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CAbdominal Viscera (Solid Organs) .............. 338Breast ......................................................... 355Cardiac ....................................................... 366Chest .......................................................... 379Computer Applications ............................... 396Contrast Media ........................................... 402Genitourinary .............................................. 405GI Tract ....................................................... 422Head and Neck ........................................... 439Interventional Radiology ............................. 449Molecular Imaging ...................................... 463Musculoskeletal .......................................... 465Neuro .......................................................... 482Pediatric ...................................................... 502Physics in Radiology .................................. 512Radiographers ............................................ 519Vascular ...................................................... 522

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C-001 Portal biliopathy: Imaging findings J.P. Cruz, F.D. Frota, A. Huete, F. Cruz; Santiago/CL (jpcruz81@gmail.com)

Learning Objectives: To show the radiological alterations of the portal biliopathy in Doppler US, CT and MRI images that although are characteristic can be confused with other diseases like sclerosing cholangitis, cholangiocarcinoma, hepatic cir-rhosis or Caroli´s disease. To describe the best radiological finds we use a series composed by 8 patients, in which the diagnosis was made by a combination of Doppler US, multi-detector CT and MRI.Background: The portal biliopathy is a relatively recent term used to describe the morphologic alterations of the biliary ducts that can happen in patients with portal hypertension. These changes frequently are seen in patients with extrahepatic biliary hypertension (presinusoidal) secondary to trombosis of the main portal vein that gives rises to dilated pericholedochal and periportal collaterals that bypass the portal vein obstruction. This collateral circulation takes to formation of varices on the hepatoduodenal ligament, cavernous transformation of the portal vein.Imaging Findings: The radiological characteristics of the portal biliopathy are mainly: 1) Extrinsic compression of the common duct; 2) Cavernous transforma-tion of the portal vein; 3) Perivesicular varices; 4) Biliary stricture and dilatation of the proximal biliary tree due to extrinsic compression by dilated venous collaterals or isquemy.Conclusion: In our series, one of the patients, at the time of the diagnoses, already had a secondary biliary cirrhosis due to chronic biliary obstruction. In this case the alterations of the biliary duct are not reverted after the treatment; therefore, the importance of the diagnosis and precocious treatment.

C-002 Uncommon obstructive causes of extrahepatic bile duct: Imaging findings and clinical significance S. Kim1, H. Shin1, I. Kim1, H. Kim2, D. Lee2, Y. Ko2; 1Choongnam/KR, 2Seoul/KR (rad2000@hanmail.net)

Learning Objectives: To illustrate and discuss the imaging findings of uncommon obstructive causes and conditions of extrahepatic bile duct and correlate with ERCP and pathologic findings. To discuss the clinical significance of these conditions.Background: The common causes of bile duct obstruction or dilatation are biliary stone and malignant tumors arising from the bile duct or the periampullary area. The diagnostic performance of CT and MRI for common obstructive causes of bile duct is good. However, we often encounter cases, which show dilatation of biliary trees without evidence of stone or tumor in the extrahepatic bile duct. Various uncommon conditions may cause obstruction of the extrahepatic bile duct.Procedure Details: Uncommon obstructive conditions of the extrahepatic bile duct were classified as extraductal causes (portal biliopathy, metastasis, lymphoma, Mirizzi syndorme), intraductal causes (sump syndrome, tumor thrombus, pyogenic granuloma, papillomatosis, biliary cystadenoma) and periampullary causes (Lemmel syndrome, choledochocele, uncommon ampullary tumors, autoimmune pancreati-tis). We will also present diseases mimicking bile duct obstruction.Conclusion: Thus, familiarity with the various uncommon causes of bile duct obstruction would be helpful in the accurate diagnosis of biliary pathology.

C-003 The MRCP features of biliary cast syndrome A.P. Winterbottom, A.S. Krishnan, A.E. Gimson, C.J.E. Watson, D.J. Lomas; Cambridge/UK (winterbottom771@hotmail.com)

Learning Objectives: 1 Illustrate the spectrum of MRCP features of biliary cast syndrome (BCS). 2 Describe the aetiology of this rare complication of liver transplantation that typically leads to graft failure. 3 Emphasise the importance of investigating for underlying hepaticischaemia.Background: BCS is the presence of obstructing casts within the biliary system secondary to necrosis of the bile duct epithelium, most commonly in patients fol-lowing liver transplantation. BCS was originally described in the development phase of transplantation associated with long ischaemic times between graft retrieval and implantation. Presentation may be acute or chronic and associated with sequelae of biliary stasis, infection, and duct and hepatocyte damage, typically leading to graft failure and retransplantation. Owing to the shortage of donor livers, graft acceptance criteria have relaxed in recent years and BCS is re-emerging.

Imaging Findings: Using three proven cases of BCS that presented during the last 2 years, the spectrum of MRCP features are demonstrated. Early features of biliary epithelium sloughing and late features of cast, stricture and abscess formation are illustrated and correlated with ERCP, PTC, CT and US. The role of imaging andthe impact on clinical management at different stages of presentation and the eventual outcomes are discussed. The importance of establishing hepatic artery patency and investigating causes of ischaemia are emphasised.Conclusion: The MRCP features of a rare but serious biliary complication of liver transplantation are described, illustrated and compared with other imaging techniques. The role of imaging in the management and the underlying aetiology are reviewed.

C-004 Postsurgical bile leaks and bile duct strictures: From ultrasound to endoscopic retrograde cholangiopancreatography M.D.G.A. Certo1, L. Lopes2; 1Santo Tirso/PT, 2Viana do Castelo/PT (manuelacerto@sapo.pt)

Learning Objectives: To describe and classify the different types of postsurgical bile duct injury; to discuss the role of imaging and endoscopic retrograde cholan-giopancreatography (ERCP) in the management of biliary injuriesBackground: Biliary injury is the most common complication of any surgical procedure involving the liver and/or bile ducts. Bile duct injury has always been a risk for cholecystectomy, but its incidence increases sharply when laparoscopic surgery is introduced.Management of patients with postsurgical bile duct injuries requires a multidisci-plinary approach of radiologists, endoscopists, and surgeons.Imaging Findings: The postoperative clinical presentation varies widely and is influenced by the type of injury.The first step is to perform ultrsound (US) to investigate the presence of ductal dilatation or fluid collections.Biliary dilatation is often absent because the biliary system is decompressed by the leak. In the presence of fluid collections, percutaneous needle aspiration may differentiate an abscess from a biloma. When ductal dilatation is present or needle aspiration yields bile, an ERCP should be the next procedure.Four types of bile duct injury can be recognized on ERCP. Type A: Cystic duct leaks or leakage from aberrant or peripheral hepatic radicles. Type B: Major bile duct leaks with or without concomitant biliary strictures. Type C: Bile duct strictures without bile leakage. Type D: Complete transactions of the duct with or without excision of some portion of the biliary tree.Conclusion: Adequate management of these injuries requires an early diagnosis with a low threshold for performing an ERCP.

C-005 Gallbladder’s diseases on MDCT: Revisited N.P. Silva, A. Almeida, M. Castro, B. Viamonte, L. Melão, J.M. Pereira; Porto/PT (nunopsi1@gmail.com)

Learning Objectives: The aim of this study is to review the spectrum of imaging findings of gallbladder’s diseases, with emphasis on MDCT.Background: Today, sonography remains the imaging modality of choice for the initial evaluation of patients with symptoms suggestive of gallbladder’s disease. CT and MR are generally relegated to a secondary role, being specially useful in the more detailed evaluation of a previously known affection, such as staging of a neoplastic lesion, or in the evaluation of the complications of acute diseases. On the other hand, due to the widespread use of CT and the often asymptomatic nature of some of the diseases affecting the gallbladder, we should be prepared to face such conditions as incidental findings on CT studies made for any other reason.Imaging Findings: The authors extensively discuss the imaging features of gallbladder’s pathology, illustrating it with examples from their clinical practice, on a 64-slice CT scanner.Conclusion: Due to the widespread use of CT, abnormalities of the gallbladder are being increasingly found, either in targeted examinations or by accident. Understanding the spectrum of the findings of gallbladder pathology can optimize patient management.

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C-006 Blood supply of intrahepatic bile duct: Histopathological findings of peribiliary plexus and its significance on hepatic imaging S. Kobayashi, O. Matsui, T. Gabata, J. Sanada, W. Koda, Y. Nakanuma; Kanazawa/JP

Learning Objectives: To familiarize the histopathological findings of peribiliary plexus (PBP), blood supply system of the intrahepatic bile duct. To understand the significance of PBP on hepatic imaging.Background: The biliary tree is supplied primarily by hepatic arterial branches that give off a vascular plexus around the bile duct (peribiliary plexus, PBP). Histopatho-logically, this unique blood supply system shows various kinds of changes under hepatobiliary diseases. Also, morphological and/or functional changes of PBP are sometimes observed directly or indirectly on hepatic imaging.Imaging Findings: PBP around the intrahepatic large bile ducts and septal bile ducts in normal liver consists of three layers: inner, intermediate and outer layer. The inner layer of PBP increases in number under active inflammation of the portal tract, such as in hepatolithiasis and early stage of primary biliary cirrhosis. The vessels in all the layers of PBP show increase in number and are dilated in liver cirrhosis (LC). After transcatheter arterial embolization (TAE) for treatment of hepatocellular carcinoma (HCC), PBP shows marked decrease, especially in the inner layer, and it might be concerned with the occurrence of bile duct injury after TAE. On liver imaging, dilated PBP may be visualized as cavernous transformation in portal vein thrombosis. Functional status of PBP might have intimate relation with the visualization of central and peripheral zonal differentiation of the liver.Conclusion: We will demonstrate the histopathological findings of PBP and de-scribe the significance of PBP on liver imaging.

C-007 Prediction of survival with F-18 fluorodeoxyglucose-positron emission tomography in biliary carcinoma H. Furukawa, H. Ikuma, K. Yokoe-Asakura, K. Uesaka; Shizuoka/JP

Purpose: To determine whether high uptake of FDG predicted overall survival independently of clinicopathological characteristics.Methods and Materials: Sixty-nine patients (40 men, 29 women) at a median age of 69 years (range, 46-84) with biliary carcinoma underwent FDG-PET before cancer treatment. The maximum standard uptake values (maxSUV) were calculated as an index of FDG uptake. Tumors were localized in the bile duct in 51 patients and in the gallbladder in 18. Fifty-one of 58 surgically treated patients underwent resection and their diseases were staged by histopathological analysis of the resected specimen.Results: Receiving operator characteristics curve demonstrated a maxSUV of 6.3 to be the optimal cut-off point (area under the curve, 0.695; standard error of 0.065). A high uptake of FDG assessed by maxSUV was associated with gender (p=0.028), TNM staging (p=0.009), tumor morphology (nodular or infiltrating, p=0.005), and resection (p=0.009). The 3-year survival of patients with a maxSUV of 6.3 or less was 77%, whereas it was 42% for those patients with values greater than 6.3 (odds ratio 2.976; 95%CI, 1.298-6.826). Univariate analysis showed that TNM staging (p 0.001), T status (p 0.001), N status (p 0.001), M status (p 0.001), resection (p 0.001), and maxSUV (p 0.007) were significant prognostic factors for overall survival. Multivariate analysis showed the only independent predictor of survival was TNM staging (odds ratio 5.121; 95%CI, 1.951-13.440).Conclusion: High uptake of FDG in biliary carcinoma is associated with advanced disease and portends poor survival. Quantitative FDG-PET is a valuable adjunct to conventional clinical and histologic assessments.

C-008 Evaluation of the gross type and longitudinal extent of extrahepatic cholangiocarcinomas on contrast-enhanced MDCT H. Seo1, J. Lee1, I. Kim2, J. Han1, S. Kim1, J. Jang1, S.-W. Kim1, B. Choi1; 1Seoul/KR, 2Je-ju/KR

Purpose: To determine the accuracy of the contrast-enhanced multidetector row computed tomography (MDCT) in classifying the morphologic subtype and revealing the longitudinal extent of extrahepatic cholangiocarcinomas.Methods and Materials: Two radiologists retrospectively reviewed the preoperative MDCT images of 56 patients undergone the surgical treatment for extrahepatic cholangiocarcinomas from 2000 to 2006. The reviewers classified the morphologic subtypes and measured the enhancing segment of the bile duct with wall thick-ening on axial images, and then reviewed axial and multiplanar reconstruction (MPR) images in 39 patients. The results of image analysis were compared with pathological findings.

Results: The accuracy of MDCT for morphologic classification was 78.9%. The differences between radiologic and pathologic measurements of longitudinal ex-tent of the tumors ranged from 0 mm to 53.5 mm (mean: 5.89 11.42 mm). There was moderate correlation between the two measurements of longitudinal extent of the tumors (P 0.05, =0.4455). In 35 patients, MDCT measurements were not significantly different from pathologic measurements (62.5%). In 18 patients, CT underestimated the longitudinal extent of the tumor more than 6 mm (32.1%). In the 39 patients with MPR images, the correlation between CT measurements and pathologic measurements of the longitudinal extent was better in combined inter-pretation of axial and coronal images (P 0.05, =0.4153) than in interpretation of axial only images (P 0.05, =0.2652).Conclusion: Our results demonstrate that MDCT can classify the morphologic subtype of EHC correctly. However, CT had a strong tendency to underestimate the longitudinal tumor extent compared to the pathologic results.

C-009 Transient hepatic attenuation difference (THAD) in biliary vessels diseases (BVD) S. Pradella, B. Duranti, N. Centi, M. Vangelisti, G. Faralli, N. Villari, S. Colagrande; Florence/IT (pradella3@yahoo.it)

Purpose: THADs have been widely described; however, their association with BVD is not well known. We retrospectively evaluate the incidence and the diagnostic role of THAD in patients with specific BVD.Methods and Materials: 1833 patients underwent biphasic CT examinations (2003-October/2007-June) of the upper abdomen. We selected patients with fol-lowing diagnoses: biliary tree dilation due to extrahepatic biliary obstruction (A), intrahepatic or hilar cholangiocarcinoma (B), and cholangitis (C). In each group, presence, pattern, and density of any THAD were identified. Patients without any demonstrable clinical/imaging signs of liver/biliary pathology represented the control group.Results: 53 patients, 30 men; mean age 66 (13.7) yr; (79 CT) met the inclusion criteria (study group). THADs were observed in 36/53 (67.9%) and 20/1124 (1.78%) in study and control groups, respectively. Statistical analysis demonstrated a significant association between groups and THAD patterns (p 0.0001). A) 11/20 (55%) patients showed a low density linear railway-like THAD around dilated biliary vessels (peribiliary). B) 15/19 (79%) demonstrated a high density roughly triangular shaped THAD with the apex directed to the hepatic hilum involving one or more segments (sectorial) due to portal infiltration. C) 10/14 (71%) variously shaped all along inflamed biliary vessels (polymorphous). In 14 CT patients followed-up a THPE disappearance/less evidence was demonstrated. In 2 cases a previous CT showed only the arterial phenomenon without any detectable mass.Conclusion: Evaluation of THAD can be an additional diagnostic tool in patients with BVD. Sectorial-high-density THAD correlates with portal infiltration while polymorphous pattern links with cholangitis. Diffused peribiliary low-density THAD matches with biliary tree ectasia, independently from etiology.

C-010 Portal biliopathy: MR cholangiopancreatography features E. Özkavukcu, A. Erden, I. Erden; Ankara/TR (eozkavukcu@gmail.com)

Purpose: To evaluate the MR cholangiopancreatography (MRCP) features of portal biliopathy and their frequencies.Methods and Materials: Sixteen patients (9 male, 7 female) with portal cavernomas who had undergone MRCP were involved in the study. Patients` ages were between 21 and 60 years (mean: 39.3 years). Patients with other causes of biliary abnormality or tumors causing biliary obstruction were not included in the study. Two radiologists evaluated all the MRCP examinations retrospectively for the presence of biliary ste-nosis, upstream ductal dilatation, wavy appearance of the biliary ducts, angulation of the common bile duct (CBD), and cholelithiasis. Finally, MRCP appearances were classified using the classification system suggested by Chandra et al.Results: All patients had either one sign of portal biliopathy. Except one, all of the patients (n=15; 93.7%) had either solitary, but mostly multiple biliary stenosis (n=5; 33.3%, and n=10; 66.6%, respectively). Upstream dilatation was observed in 11 patients (68.7%). Fourteen patients (87.5%) had wavy appearance of the biliary ducts. No patient had cholelithiasis. Twelve patients (75%) had angulation of the CBD. According to the classification suggested by Chandra et al., 6 patients (37.5%) had type I, 6 patients (37.5%) had type IIIa, and 4 (25%) patients had type IIIb changes in the biliary tree.Conclusion: Portal biliopathy is very common in patients with portal cavernomas. In this study, the MRCP findings of portal biliopathy in the order of their frequencies were: biliary stenosis, wavy appearance of the bile ducts, angulation of the CBD, and upstream dilatation.

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C-011 Peripheral cholangiocarcinoma (PCC): Enhancement features on enhanced MR imaging with gadobenate dimeglumine (Gd-BOPTA) L. Grazioli1, L. Romanini1, M. Bondioni1, B. Frittoli1, M. Kirchin2; 1Brescia/IT, 2Milan/IT

Purpose: To evaluate gadobenate dimeglumine (Gd-BOPTA, MultiHance®) for the differentiation of peripheral cholangiocarcinoma (PCC) from metastases and other common focal liver lesions (FLLs).Methods and Materials: 79 patients (24 PCC, 22 metastases, 33 other FLLs) were evaluated. Unenhanced T2- and T1-weighted images were acquired pre-contrast injection followed by repetition of the T1-weighted sequence during the dynamic and delayed hepatobiliary (up to 3h post-injection) phases after administration of Gd-BOPTA. Image evaluation was performed by two blinded radiologists in terms of signal-to-noise ratio (SNR) on pre-contrast and hepatobiliary phase T1-weighted images, lesion enhancement pattern, % lesion necrosis, peripheral contrast wash-out and delayed phase contrast pooling.Results: No significant differences were noted between lesion types in terms of SNR changes from pre-contrast to delayed post-contrast images. A significant (p=0.009) correlation was noted on dynamic images for the degree of peripheral enhancement of PCC lesions and other FLLs but not between PCC lesions and metastases. No differences were noted for % lesion necrosis. Delayed pooling was more frequent in PCC lesions but was not significant (p=0.12). Significant correla-tions were noted between PCC and other FLLs for peripheral wash-out during the dynamic (p=0.018) and hepatobiliary (p=0.003) phases.Conclusion: Peripheral enhancement and wash-out aid in the differentiation of PCC from other FLLs. Contrast pooling in the hepatobiliary phase may help in the differentiation of PCC from metastases.

C-012 Clinical usefulness of MRCP and MR imaging in patients with hepatolithiasis: Focusing on variable complications J. Kim, H. Eun, S. Hong, G. Kwon, D. Choi, J. Hwang; Seoul/KR (junghkim@medimail.co.kr)

Learning Objectives: To learn the clinical considerations and roles of MRCP and MRI in patients with hepatolithiasis. To describe the specific imaging features of hepatolithiasis and its complications on MRCP and MRI. To learn the specific key differential diagnostic points malignant complications from benign complications.Background: MRCP is a noninvasive technique that has proven to be accurate in hepatolithiasis. The purpose of this exhibit is to describe the imaging features of hepatolithiasis and its complications on MRCP and MRI.Imaging Findings: During 28 month period, 249 patients underwent MRCP and MRI for hepatolithiasis. The results were derived from 249 patients with hepatoli-thiasis and its benign complications including acute cholecystitis (n=32), adeno-myomatosis (n=17), mirizzi’s syndrome (n=7), pocelain GB (n=2), abscess (n=18), biloma (n=3), pancreatitis (n=13), enteric fistula (n=3), ancillary findings including choledochal cyst (n=4), biliary web (n=2), and its malignant complications including cholangiocarcinoma (peripheral=12; hilar=4; extrahepatic=1), IPMT of the bile duct (n=2), papillomatosis (n=1), GB cancer (n=2).Conclusion: The MRCP and MRI can be an effective diagnostic method in the work up for hepatolithiasis. We can learn the specific key differential diagnostic point malignant complications from benign complications on advanced MR imaging.

C-013 Pineapple juice with gadolinium used as negative oral contrast in magnetic resonance cholangiopancreatography: A multicentric study J.A. Duarte, A. Furtado, C.A. Marroni; Porto Alegre/BR (juavila2003@yahoo.com.br)

Purpose: The aim of our study was to evaluate the use of pineapple juice (PJ) solution with gadolinium as a negative contrast agent for magnetic resonance cholangiopancreatography (MRCP).Methods and Materials: A multicentric study with three institutions and 71 patients who underwent MRCP. The subjects were examined before and after administration of 180 ml of PJ with gadolinium. Image quality scores were obtained before and after contrast ingestion in six different sites of the biliary tree. Three radiologists evaluated the films and a statistical analysis was made.Results: No adverse reaction was reported after ingestion of PJ/gadolinium solu-tion. There were no complaints about the taste or amount of the solution. T test and Wilcoxon test with significant threshold: the image quality improved statisti-cally (p 0.001) for the three radiologists (R1, R2 e R3). The score improvement for R1 was 0.9; for R2 0.86 and for R3 0.68 after ingestion of the solution. The

radiologists mean before PJ ingestion was 2.48 0.735 (R1); 2.62 0.582 (R2); and 2.1870 0.78577 (R3) (mean standard deviation). After ingestion the improvement was: 3.38 0.656 (R1); 3.48 0.574 (R2) and 2.8728 0.95984 (R3).Conclusion: Ingestion of 180 ml of PJ/gadolinium solution eliminated efficiently the gastroduodenal SI in MRCP, improving significantly the rates of complete visualiza-tion of the pancreatobiliary ducts (P 0.01) for the three radiologists. All patients easily ingested the contrast solution and found the solution palatable. PJ/gadolinium constituted an efficient negative oral contrast agent for MRCP.

C-014 The role of MR cholangiography in patients with iatrogenic bile duct injury after cholecystectomy F. Todua, K. Lashkhi, S. Kakhadze, M. Gurgenidze, K. Gigauri, R. Kharadze, G. Svanidze; Tbilisi/GE (rkharadze@yahoo.com)

Purpose: Our aim was to assess the diagnostic value of magnetic resonance cholangiography (MRC) in the evaluation of iatrogenic bile duct injuries after cholecystectomy.Methods and Materials: 17 patients (13 women and 4 men; mean age, 45 years) with suspected bile duct injury as a result of laparoscopic cholecystectomy (13 patients) and open cholecystectomy (4 patients) underwent MRC on a 1.5-T (Sie-mens Avanto). Patients were examined with contiguous thin-section images in the transverse and the optimal coronal oblique planes. MR images were evaluated for bile duct discontinuity, presence or absence of biliary dilation, stricture, excision injury, and free fluid. Bile duct excision and stricture were classified according to the Bismuth classification. Final diagnosis was made on the basis of findings at surgery in 11 patients, on percutaneous transhepatic cholangiography (PTC) in one patient, and on endoscopic retrograde cholangiography (ERC) and at clinical follow-up until hospital discharge in the remaining 5 patients.Results: In 15 patients, injury of the bile duct was observed. 3 patients had Bismuth type I injury; 2 patients, type II injury; 9 patients, type III injury; and one patient type IV. 3 patients showed findings suggestive of leakage from the cystic duct remnant, which were confirmed on ERC.Conclusion: MR cholangiography is an accurate diagnostic technique in the iden-tification of postoperative bile duct injuries. Only this technique allows delineation of the duct proximal and distal to the stricture and accurate classification of these injuries that facilitate planning treatment tactics.

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Liver

C-015 The role of imaging techniques in acute bleeding liver: A rational approach J. Quintero, J. Sampere, S. Mourelo, J. Jiménez, I. Urra, E. Barluenga; Badalona/ES (jcquintero.germanstrias@gencat.net)

Learning Objectives: The purpose of this exhibit is to: 1) Recognize the imaging radiology manifestation of hemoperitoneum originating in the liver and identify key CT features that may help direct management. 2) Establish the differential diagnosis of hemorrhagic hepatic conditions, traumatic and non-traumatic.Background: Spontaneous hepatic bleeding is a rare condition. In the absence of trauma or anticoagulant therapy, hepatic hemorrhage may be due to underlying liver disease. The most common causes of non-traumatic hepatic hemorrhage are hepatocellular carcinoma and hepatocellular adenoma. Such hemorrhage can also occur in patients with other liver tumors and other conditions.Imaging Findings: We reviewed retrospectively 25 patients with acute bleeding liver diagnosed in our institution. We present a comprehensive algorithmic approach to diagnose in acute bleeding liver 1) traumatic conditions (10); 2) hepatocellular carcinoma (5); 3) hepatocellular adenoma (2); 4) other liver neoplasms such as focal nodular hyperplasia (1), hepatic hemangioma (1), hepatic metastasis (3) and primary hepatic lymphoma (1); 5) other conditions associated with spontaneous hepatic hemorrhage such as HELLP syndrome (2), amyloidosis, peliosis hepatis, connective tissue diseases, infectious diseases and parasitic diseases (1).Conclusion: Hemoperitoneum may occur in various emergent conditions. In the trauma setting, evidence of intraperitoneal blood depicted at CT should lead the radiologist to conduct a careful search of images for the injured visceral organ. Imaging plays a significant role in the diagnosis and management of this potentially lethal entity.

C-016 Magnetic resonance elastography of liver: Technique and clinical application S.K. Venkatesh1, M. Yin2, R.L. Ehman2; 1Singapore/SG, 2Rochester, MN/US (dnrskv@nus.edu.sg)

Learning Objectives: To describe magnetic resonance elastography (MRE) tech-nique of the liver. To describe the application of MRE in diffuse liver pathologies.Background: Liver fibrosis is the end result of injuries from various etiologies to liver parenchyma. Currently the gold standard for the diagnosis and grading of liver fibrosis is liver biopsy. Fibrosis of liver can also be assessed by measuring the elasticity of the liver. MRE, a new technique has the potential to provide quantitative measurement of the mechanical properties of the biological tissues. MRE measures mean hepatic tissue stiffness which is related to the degree of fibrosis.Procedure Details: MRE was performed on a 1.5 T scanner with a passive driver placed against the right chest wall overlying the liver. A continuous acoustic vibration at 60 Hz transmitted from an active driver to the passive driver via a flexible vinyl tube was used to produce propagating shear waves in the liver. The propagating shear waves were imaged with a gradient echo based MRE sequence. A stiffness map or elastogram was automatically processed using an inversion algorithm. The technique was successfully implemented and well-tolerated in patients. Normal liver parenchyma showed stiffness values 2.9 kPa and higher stiffnesses were seen in liver fibrosis. Body habitus, anatomical variations, ascites and bowel interposition did not affect the MRE study suggesting robustness of the technique.Conclusion: MRE is a useful non-invasive technique for quantitative evaluation of mechanical properties of liver parenchyma and improves characterization of diffuse and focal pathologies of liver.

C-017 Third in-flow as a cause of hepatic pseudo-lesions C. Vallone1, F. Marra1, C. Bertolani1, M. Fazi1, L. Grazioli2, N. Villari1, S. Colagrande1; 1Florence/IT, 2Brescia/IT (bigvalley72@gmail.com)

Learning Objectives: To describe the main CT/MR features of the hepatic pseudo-lesions due to the third-inflow, based on a series of 78 patients.Background: The liver has a dual blood supply with compensatory relationships between the two inflows. A percentage (2-4%) is also due to the third-inflow, a non-portal-venous system which provides small areas of parenchyma acting, accordingly to the pressure gradient, as supply or drainage vessels. These veins enter the liver separately and communicate with the intrahepatic portal branches, causing localized portal hypoperfusion with arterial reaction. Persistent hemodynamic changes can

determine inadequate regional metabolic supply that result in focal sparing in fatty liver, or nodular steatosis in normal liver. Such pseudo-lesions, often detected in neoplastic patients after chemotherapy, represent a diagnostic challenge because may mimic tumorous lesions.Imaging Findings: Although detectable in all segments, except the first, fatty and sparing areas are mainly localized (75%) in segments III-IV-V. They prevalently appear as single (55%) or multiple (45%) round masses with a maximum diameter of 2 cm, left and/or right sided to the gallbladder and/or round ligament, or roughly polygonal area in the dorsal portion of segment IV. At contrastographic imaging, skip areas can enhance (25-30%) during the arterial phase, never showing wash-out phenomenon at portal phase. All accumulate hepato-specific gadolinium chelates at liver-specific phase.Conclusion: Hepatic pseudo-lesions due to third-inflow include polimorphous hypo/hyper dense/intense areas, with/without arterial enhancement on CT/MR dynamic imaging. The knowledge of sites, characteristics and enhancement pattern of these pseudo-lesions can avoid diagnostic pitfalls.

C-018 Diffusion-weighted MR imaging of the liver A.A.A. Abdel Razek, M. Shady, M. Elbendary, E. Omram; Mansoura/EG (arazek@mans.eun.eg)

Learning Objectives: To describe the technique of diffusion-weighted MR imaging of the liver; to illustrate the role of diffusion-weighted MR imaging in the character-ization of hepatic focal lesions; to review the role of diffusion MR imaging in diffuse liver diseases; to predict the response to the treatment of hepatic focal lesions and diffuse liver disease. Background: Liver disease is a common worldwide problem. Characterization of hepatic focal lesions and degree of diffuse liver cirrhosis is essential for treatment planning.Imaging Findings: Technological advance has allowed the expansion of the role of diffusion-weighted MR imaging into the abdomen. Diffusion-weighted MR imaging plays a role in the differentiation of benign from malignant hepatic focal lesions as well as in the differentiation of cystic or necrotic hepatic tumors from abscess. Also, it can be used for the follow-up of hepatic tumors after radiofrequency or chemotherapy to detect tumor viability. It has a fundamental role in quantification of hepatic fibrosis as well as for characterization of diffuse liver diseases.Conclusion: We conclude that diffusion-weighted MR imaging can be incorporated into the routine MR pulse sequence of the liver. It has been used for characteriza-tion of hepatic focal lesions, grading of hepatic fibrosis and monitoring patients after treatment.

C-019 The treated liver: A pictorial review of imaging findings following liver-directed therapy, short-term and long-term follow-up S. Carter, C. Farinas, M. Patnana, J. Szklaruk; Houston, TX/US (yeinu@aol.com)

Learning Objectives: To review the indications and techniques of different liver-directed therapies. To learn the CT and MRI appearance of the immediate and long-term follow-up of various liver directed therapies.Background: There have been recent advances in techniques and an increased utilization of liver-directed therapy. The most commonly utilized techniques for liver-directed therapy include partial hepatectomy, radiofrequency ablation, portal vein embolization, trans-arterial chemo-embolization, biliary stent palcement, trans-jugular intrahepatic portal systemic shunting, radiation therapy, and Y-90 microspheres.Computed tomography (CT) and magnetic resonance imaging (MRI) are commonly used for the evaluation of patients with liver disease. Familiarity with the appear-ance of the liver in the immediate and in the long-term follow-up is essential for accurate image interpretation.Imaging Findings: This interactive electronic exhibit will review the current concepts on liver-directed therapies and the imaging features for immediate and long-term follow-up. The participant will select from a master menu a specific therapy of interest and will then be asked to select from a list of topics that include clinical background, immediate imaging features, and long-term imaging features. The clinical background section will include a discussion on the technique, indications, success rate, and inclusion criteria for each technique. The exhibit will then illustrate the evolution of the imaging findings.Conclusion: This exhibit will teach the participant the indications, techniques, and immediate and long-term imaging features of various liver-directed therapies.

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C-020 Role of contrast-enhanced ultrasound in the characterization of hypervascular focal liver lesions: Spectrum of imaging findings T.V. Bartolotta, A. Taibbi, M. Galia, E. Grassedonio, A. Galluzzo, V. Alaimo, M. Midiri; Palermo/IT (tv_bartolotta@yahoo.com)

Learning Objectives: To illustrate the spectrum of imaging features of hypervas-cular liver lesions (HLL) on contrast-enhanced ultrasound (CEUS).Background: Liver lesions may be classified as hypovascular and hypervascular based on the degree of arterial blood supply. Usually, HLLs include hemangioma, fo-cal nodular hyperplasia, hepatocellular adenoma, hepatocellular carcinoma, fibrola-mellar carcinoma and metastases from particular primary tumors. Nevertheless, at gray-scale US evaluation, the characterization of liver lesions is not achievable in the majority of cases and represents a diagnostic challenge to the radiologists. As widely reported in literature, CEUS has a diagnostic performance comparable to more expensive and invasive imaging techniques as CT and MR.Imaging Findings: Two experienced radiologists retrospectively reviewed by consensus SonoVue®-enhanced US of 124 patients (70 women, 54 men; mean age: 53.3 years) with definitively diagnosed 125 HLLs (mean size: 3.4 cm; 32 hem-angiomas, 37 focal nodular hyperplasias (FNH), 29 metastases, 25 hepatocellular carcinomas (HCC), 1 hemangiopericytoma), evaluating dynamic enhancement pattern of each lesion, in comparison with adjacent liver parenchyma. On CEUS, 24/32 (75%) hemangiomas showed peripheral hyperechoic nodules followed by progressive centripetal fill-in; all FNHs were highly hypervascular in the arterial phase keeping contrast-medium also in the late phase and showing “spoke-wheel sign” and/or central scar in 19/37 cases; 29 metastases and 23/25 HCCs, even if hypervascular in the arterial phase, appeared hypoechoic in portal-venous or late phase.Conclusion: CEUS can be considered a reliable technique for the characterization of HLLs, since it provides useful findings and makes the radiologist more confident of the final diagnosis.

C-021 Various extrahepatic metastasis of hepatocellular carcinoma: Spectrum of imaging findings J. Kim, Y. Lee, J. Byun, S. Oh, S. Rha, S. Jung, Y. Ku; Seoul/KR (yjleerad@catholic.ac.kr)

Learning Objectives:1. To learn the spectrum of various extrahepatic metasta-ses of hepatocellular carcinoma. 2. To learn the characteristic imaging findings in extrahepatic metastasis of hepatocellular carcinoma for differentiation between hepatocellular carcinoma and other metastatic tumors.Background:Various extrahepatic metastases of hepatocellular carcinoma is com-mon, especially in advanced intrahepatic tumor. Uncommon extrahepatic metastasis of hepatocellular carcinoma can be confused with primary or other metastatic tumors. Knowledge of imaging features of various extrahepatic metastases of hepatocellular carcinoma is essential for the precise evaluation of the spread of he-patocellular carcinoma and determination of the appropriate treatment method.Imaging Findings:1. Imaging findings of common extrahepatic metastases of hepatocellular carcinoma: lung, bone, regional lymph node and adrenal gland. 2. Imaging findings of uncommon extrahepatic metastasis of hepatocellular carcinoma: mesentery, peritoneum, brain, stomach, ovary, etc. Conclusion: We will illustrate the spectrum of imaging findings in various extra-hepatic metastases of hepatocelluar carcinoma involving whole body and review characteristic imaging findings in extrahepatic metastasis of hepatocellular carci-noma for differentiation from other metastastic tumors.

C-022 Changes in MR-imaging features of patients with hepatocellular carcinoma following sorafenib monotherapy: Incidence, time of occurrence and significance M.S. Horger, M. Bitzer, U. Lauer, C. Schraml, M.P. Lichy, C.D. Claussen; Tübingen/DE

Learning Objectives: To illustrate the spectrum of MRI-signal changes occurring in patients with hepatocellular carcinoma (HCC) after onset of monotherapy with an oral multikinase inhibitor-sorafenib.Background: The precise mechanism of action by which sorafenib exerts its clinical effects, and the etiologic role of the Raf/MEK/ERK pathway are undergo-ing further investigation, but in HCC, sorafenib may be acting through inhibition of angiogenesis.Imaging Findings: MR-signal changes in HCCs at follow-up depend on the initial characteristics of the tumor. Patients with HCCs that are either hypointense or isoin-

tense to normal liver on T1-weighted images T1WI and hyperintense or isointense on T2WI, at baseline, are showing increase in signal on T1WI and often also on T2WI, at short-term follow-up (after ca. 2-3 weeks). They also present synchro-nously a decrease in signal intensity on Gd-enhanced fat saturated T1WI and an increase in tumor necrosis. Contrary, in patients showing hyperintense signal on T1WI (corresponding generally to well-differentiated HCCs) and hypointense signal on T2WI, at baseline, MR-signal does not show relevant abnormalities, at follow-up. In these cases, tumor response is demonstrated at best on Gd-enhanced T1WI where the signal decreases while necrosis is showing progress. In these patients, signal abnormalities are milder and the course of HCC more stable.Conclusion: MR-signal abnormalities occurring in hepatocellular carcinomas at follow-up in patients receiving therapy with sorafenib are predictable markers of response supposed to represent hemorrhagic necrosis due to inhibition of receptor tyrosine kinases involved in tumor growth and angiogenesis.

C-023 Diffusion-weighted MRI of the cirrhotic liver: Advantages and limits J.-S. Yu, J.-J. Chung, J. Kim; Seoul/KR (yjsrad97@yuhs.ac)

Learning Objectives: To illustrate the diffusion-weighted imaging (DWI) features of focal lesions in the cirrhotic liver. To outline the advantages and limits of the technique. To describe the feasibility and best indications of the technique in the cirrhotic liver.Background: Non-invasive diagnosis of cirrhotic nodules and degree of cirrhosis are always challenging during the daily practice of hepatic MRI. In this exhibit, we will describe the initial and follow-up imaging features of hepatocellular carcinomas (HCCs) before and after treatment by the DWI technique. Besides the routine pro-tocol of hepatic MRI using a 1.5-T system (Magnetom Avanto; Siemens, Erlangen, Germany) consisted of pre- and post-contrast Gd-enhanced dynamic imaging with or without liver-specific contrast agents, DWI was obtained before and after the injection of contrast agent using spin-echo echo-planar imaging. Apparent diffusion coefficient (ADC) map was automatically obtained and ADC value of each focal lesion was calculated using ROIs.Imaging Findings: On DWIs, the signal intensity of HCCs was not constant on the initial detection; however, marginally recurrent HCCs or liver-to-liver metastatic nodules showed hyperintensity and well correlated with the hypervascularity on the dynamic imaging studies. The ADC value tended to be increased for the acutely necrotic HCCs just after chemoembolization or radiofrequency ablation and de-creased for the chronically necrotic lesions.Conclusion: For detection and characterization of the focal lesions in the cirrhotic liver, DWI provides additional information; however, direct measurement of ADC still has very limited value for individual lesion characterization.

C-024 Focal nodular hyperplasia or hepatic adenoma? The role of MRI using liver-specific contrast agents in this challenging differential diagnosis P. Paolantonio, R. Ferrari, M. Rengo, P. Lucchesi, F. Vecchietti, A. Laghi; Latina/IT (paolantoniopasquale@hotmail.com)

Learning Objectives:To illustrate the pharmacodynamic and pharmacokinetic properties of Gd-BOPTA, Gd-EOB-DTPA and ferucarbutran. To show the pathologi-cal features of focal nodular hyperplasia (FNH) and hepatic adenoma (HA) with imaging correlation. To show the typical and atypical features of FNH and HA on MRI using different classes of hepatospecific contrast agents.Background:Differential diagnosis between FNH and HA is crucial for patient management. An accurate and non-invasive differential diagnosis using MRI is possible based on both dynamic imaging and functional information of liver-specific contrast agents.Procedure Details:The identification and characterization of FNH and HA requires an accurate dynamic study of the liver for the assessment of lesion vascularity. Unfortunately, a definite differential diagnosis on the basis of morphology and lesion vascularity is not always possible. Functional information offered by liver-specific contrast agents may help us in this diagnostic challenge.Conclusion:The use of liver-specific contrast agents offers functional information on lesion cellularity that are extremely useful in differentiating FNH from HA.Information on lesions of the bile ducts offered by hepatobiliary agents represent an accurate marker for FNH nodule with respect to HA.

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C-025 Diffusion-weighted MR imaging (DW-MRI) of the liver: Literature review and personal experience R. Girometti, A. Furlan, L. Cereser, M. Bazzocchi, C. Zuiani; Udine/IT (rgirometti@sirm.org)

Learning Objectives: To review the current role of DW-MRI in evaluating liver disease, especially liver fibrosis.Background: DW-MRI is a matter for intensive clinical research, due to the state-of-the-art applications in brain imaging. Measurement of the apparent diffusion coefficients (ADCs) by means of DW-MRI leads to quantification of the combined effects of microcirculation of blood (perfusion) and molecular Brownian motion of water within tissues (diffusion). Since recent development in echo-planar imaging and ultrafast gradients, the role for such technique in liver imaging is widely de-bated, particularly in characterising focal liver lesions. On the contrary, the impact of DW-MRI in the management of diffuse liver diseases, particularly liver fibrosis developing in chronic hepatopathies, has been less investigated. Currently, DW-MRI is advocated as a potentially highly reliable non-invasive alternative to percutaneous biopsy in diagnosing and staging liver fibrosis. Imaging Findings: Architectural distortion is responsible for increased or decreased water diffusion in pathologic tissues. On these bases, ADCs of liver focal lesions significantly vary according to their nature. Moreover, fibrotic liver parenchyma shows diffuse ADC decrease compared to normal values. Nevertheless, absolute values of ADCs strongly depend on the degree of diffusion-weighting, expressed by the b-value parameter, and personal data suggest a role for perfusion rather than diffusion in determining ADCs of liver fibrosis at higher b-values. Technical refinements and homogenization of study protocols are needed to improve the DW-MRI results. Conclusion: DW-MRI is a promising tool in evaluating liver disease, but our personal experience suggests a limited role in the assessment of liver fibrosis.

C-026 Nonalcoholic fatty liver disease (NAFLD) in HIV infected patients: Prevalence, characteristics and predictors F. Fiocchi, G. Ligabue, N. Squillace, C. Stentarelli, G. Guaraldi, G. Orlando, R. D’Amico, P. Loria, R. Esposito, P. Torricelli; Modena/IT (torricelli.pietro@unimore.it)

Purpose: To assess prevalence and predictors of NAFLD in HIV HAART-experi-enced patients.Methods and Materials: Consecutive patients attending a metabolic clinic. NAFLD was defined as a CT Liver to Spleen attenuation ratio 1.1 by the means of 3 density measurements. Inclusion criteria: HIV-infected patients HAART-ex-perienced ( 6 months). Exclusion criteria: HCV-Ab or HBsAg positive or heavy alcohol assumption.Results: 225 were enrolled (72.4% males; 48.5 13.2 y/o). Mean HIV duration was 147 60 months. Cumulative exposure to drug classes was: NRTI 115.05 48.04, NNRTI 38.05 30.33, PI 60.50 38.6, respectively. Mean BMI was 23.75 3.59. NAFLD was diagnosed in 83 patients (prevalence 36.89%). At univariate logis-tic regression analysis, NAFLD group differed for the following variables: male gender OR=3.2, metabolic syndrome OR=1.94, lipodystrophy phenotype of fat accumulation or mixed form (MACS classification) OR=1.66, BMI (25.1 0.4 vs 22.91 0.2, p 0.001), HDL (25.1 0.4 vs 22.91 0.2, p=0.047), ALT (51.1 52.74 vs 28.44 16.24, p 0.001), AST (33.2 22.23 vs 25.07 11.80, p 0.001), HOMA-IR (4.16 2.81 vs 2.49 1.36, p 0.001), waist/hip ratio (0.99 0.06 vs 0.94 0.06, p 0.001), NRTI exposure (124.16 44.86 vs 109.85 49.61, p=0.032), total lean mass [(DEXA) 55473 8564 vs 49337 9426, p 0.001], VAT [(CT) 167 75 vs 126 100, p 0.001], and waist (90.26 9.2 vs 83.87 9.2, p 0.001). At multivari-ate logistic regression analysis (stepwise), independent variables associated with NAFLD were as follows: ALT/AST ratio OR=4.59, male gender OR=2.49, waist circumference OR=1.06 and NRTI exposure OR=1.11. The odds of NAFLD increase of 1.11 each year of exposure to NRTI.Conclusion: Increased exposure to NRTI was associated with an increased risk of NAFLD. Traditional risk factors for NAFLD (ALT/AST, sex, waist) were confirmed in HIV-infected population.

C-027 Liver hemosiderosis: Comparison of three methods for the construction of liver T2* color parametric maps using data obtained directly from a newly designed research PACS system T.G. Maris1, K. Karolemeas2, E.E. Drakonaki1, K. Pagonidis1, N. Papanikolaou1, A.H. Karantanas1, N. Gourtsoyiannis1; 1Iraklion/GR, 2Athens/GR (tmaris@med.uoc.gr)

Purpose: To compare three methods for the calculation of liver T2* values assessed by means of quantitative MRI (T2*-qMRI) utilizing image data obtained directly by a newly designed RIS/PACS system.Methods and Materials: Liver T2* values were calculated in 40 thalassemic patients (mean age: 27 3.3 yrs, median age: 25.7 yrs) and 20 normal subjects on an 1.5 T MRI system using a breathhold 2D single slice Multi Echo (12 echoes) Gradient Echo (MEGRE) sequence with initial parameters: TR/TE1/TE12/FA 180/2.4/28.9 ms/25o. T2* calculated colour image maps were post-proccessingly reconstructed using: (a) a commercially available, (b) a conventional linear and (c) a weighted linear regression fitting algorithm. Image transferring, archiving and post-processing were performed using a research RIS/PACS system. Liver Iron Concentration (LIC) was estimated non-invasively using Yves Gandon's (Rennes University, France) methodology. Liver T2* values were correlated with LIC and Serum Ferritin Concentration (SFC) using all methods. Methods were compared using Bland Altman (BA) tests.Results: Differences of liver mean T2* values between patients and normal subjects were considered extremely significant (t=19.25, p 0.0001) using all methods. Liver ln (T2*) values were linearly correlated with LIC (a: [r=-0.85, p 0.001], b: [r=-0.97, p 0.001], c: [r=-0.99, p 0.001]). Liver ln (T2*) values were linearly correlated with SFC only when using methods b:[r=-0.62, p=0.02] and c:[r=-0.67, p=0.01]). Method (a) showed increased variability when compared with methods (b): [mean: 3.3 ms, 95% range: 6.4 ms] and (c): [mean: 2.5 ms, 95% range: 8.9 ms] using the BA test.Conclusion: T2*, as assessed using color T2* parametric maps and weighted regression analysis methods, seems to be a valuable means for an easy and ac-curate evaluation of liver hemosiderosis.

C-028 Detection of hepatocellular carcinoma: Comparison of diffusion-weighted sensitivity-encoding imaging and tetra-phase multi-detector row CT S. Takenaga1, N. Ichiba2, K. Narita3, S. Sadaoka4, D. Hayashi4, K. Fukuda4, M. Urashima4; 1Kashiwa-shi, Chiba/JP, 2Otsu-shi, Shiga/JP, 3Katsushika-ku, Tokyo/JP, 4Minato-ku, Tokyo/JP (s-takenaga@nifty.com)

Purpose: To prospectively compare the diagnostic accuracy of magnetic resonance imaging including diffusion-weighted sensitivity-encoding sequence (“DW SENSE MRI”) with that of tetra-phase multi-detector row computed tomography (MDCT) for the detection of hepatocellular carcinoma (HCC) in patients with chronic liver disease.Methods and Materials: Thirty-nine consecutive patients (34 men, 5 women) were examined prospectively with both DW SENSE MRI and tetra-phase MDCT on the previous day of transcatheter arterial chemoembolization (TACE). CT during arterial portography (CTAP) and CT hepatic arteriography (CTHA) were obtained during TACE procedure using IVR-CT/Angio system, and combined CTAP and CTHA was used as the gold standard. DW SENSE MRI was performed axially on 1.5-T MRI scanner using two b-values (50, 800 sec/mm2). Tetra-phase MDCT was performed on 16-slice-scanner using generalized protocol. Two interventional radi-ologists interpreted in consensus combined CTAP and CTHA images. MR images and tetra-phase MDCT images were independently evaluated by two radiologists. These finding were correlated on a segment-by-segment basis.Results: Combined CTAP and CTHA showed 120 HCCs (5-130 mm in diameter) in 312 segments (116 with and 196 without HCC). The mean sensitivity, specific-ity, positive predictive value, negative predictive value, and accuracy were 69.5%, 97.4%, 92.6%, 87.1%, and 88.5% for DW SENSE MRI, and 67.0%, 96.2%, 89.5%, 86.1%, and 86.9% for tetra-phase MDCT, respectively. The differences were not statistically significant (all p 0.05, McNemar test).Conclusion: DW SENSE MRI and tetra-phase MDCT show similar diagnostic ac-curacy, sensitivity, and positive predictive value for the detection of HCC in patients with chronic liver disease.

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C-029 Hepatic blood flow and liver metastasis in patients with colorectal carcinoma assessed by perfusion CT A. Satoh, K. Shuto, G. Ohira, T. Aoyagi, K. Narushima, H. Saito, T. Ohta, H. Miyauchi, N. Yanagawa, S. Okazumi; Chiba/JP (samasami@goo.jp)

Purpose: The purpose of this study is to measure the difference in liver perfusion parameters using Perfusion CT (P-CT) between colorectal carcinoma patients with and without liver metastases and of various histopathological factors.Methods and Materials: The study included 28 patients with colorectal cancer, 9 with and 19 without liver metastases. 7 of the disease-free livers were of early colorectal cancer, and 12 were of advanced. P-CT scans were performed on slices including both the aorta and portal vein. ROI placed over each vessel was used to generate a time-attenuation curve, which was used to calculate hepatic blood flow (BF, ml/min/100 g tissue) and hepatic arterial fraction (HAF) of the liver parenchyma. We compared these parameters among each case, and evaluated its correlation with TNM factors of the colorectal cancer along with the presence of liver metastasis.Results: BF and HAF were significantly higher in T3/4 compared to T1/2 (BF: P=0.0363; HAF: P=0.0489), N1/2 to N0 (BF: P=0.0043; HAF: P=0.0197), and M1 to M0 (BF: P=0.0156; HAF: P=0.0298). Cases with overt hepatic metastasis had increased BF and HAF compared to cases in colorectal cancer of early stage (BF: P=0.0273; HAF: P=0.0372).Conclusion: The BF and HAF values of the hepatic parenchyma reflect the changes in hepatic perfusion due to appearance of metastastic lesions. Perfusion CT may be a method to catch the smallest changes in aortic and portal venous flow to detect the presence of micrometastasis before visualized on any other imaging modality.

C-031 A liver function image by equivalent cross relaxation rate S. Matsushima1, H. Nishiofuku2, H. Tomozawa3, S. Era1, Y. Inaba3, Y. Kinosada1; 1Gifu/JP, 2Nara/JP, 3Nagoya/JP (smts@gifu-u.ac.jp)

Purpose: Equivalent cross-relaxation rate (ECR) imaging (ECRI) is a measurement method that can be used to quantitatively evaluate a change in the structural organi-zation by MRI. We reported that ECR value related to cellular density in the axillary lymph node. The aim of this study was to evaluate a liver function by ECRI.Methods and Materials: Fifteen patients with hepatocellular carcinoma and fifteen normal volunteers were studied. We adopted the off-resonance technique for prefer-ential saturation of the immobile protons to evaluate the equivalent cross-relaxation rate (ECR) values. The single saturation transfer pulse frequency was employed at the frequency 7 ppm downfield from the water resonance. The ECR value was defined as the percentage of signal loss between unsaturated and saturated im-ages. The ECRI were constructed on the basis of the percentage of ECR. The ECR value measured the whole liver of non-cancer pars domain without hepatocellular carcinoma. We examined a correlation of ECR value and liver function tests.Results: The normal organization showed higher ECR value. The liver with hepatitis showed lower ECR value. The liver with liver cirrhosis showed lowest ECR value. A statistically significant difference was obtained the ECR values of each tissue (p 0.05). ECR value related to AST, ALT, ChE, Albumin, Total Bilirubin, Platlet, ICG (correlation coefficient = 0.57, 0.47, 0.63, 0.68, 0.58, 0.71, 0.69).Conclusion: ECR value is related to liver function tests. Therefore, ECRI is a potentially useful method for liver function by MRI.

C-032 Multiparametric MRI [diffusion weighted imaging (DWI) and dynamic contrast enhanced-MRI (DCE)] evaluation to quantify liver fibrosis in patients with chronic hepatitis C: Preliminary resultsD. Olivié1, P.-A. Eliat1, P. Audet2, M. Mescam1, J.-S. Billiard2, J. Murphy-Lavallée2,B. N’Guyen2, M. Bilodeau2, L. Lepanto2; 1Rennes/FR, 2Montreal, QC/CA (damien.olivie@chu-rennes.fr)

Purpose: To calculate ADC by different methods and b values and different perfusion parameters during DCE MRI with BOPTA-Gd and then compare to the pathological classification in patients with chronic hepatitis C.Methods and Materials: An MRI (Avanto 1.5 T, Siemens) was conducted in patients who had a recent liver biopsy. Each examination included DCE 3D VIBE sequences using different angles. Each VIBE sequence was repeated 3 times in the same breathold and repeated 10 times during the bolus injection using 0.2 ml/kg of BOPTA-Gd. A late sequence was done 1 hour after injection. DWI sequences were performed in breathold for different b (0-50-400-1000 ms). ADC was calculated with ADC maps and Image J was used with the native sequences including small

and large ROI. The relative perfusion parameters were calculated derived from dCL (t)/dt=k1aCa (t)+k1pCp (t)-k2CL (t).Results: So far, fifteen patients have been included and were classified according to Ishak (grade 0:2, I:6, II:2, III:4, IV:1, V:0, VI:0) and Metavir (F0:2, F1:8, F2:5, F3:0, F4:0). We found a significant difference (p 0.05) between the different grades by both classifications for k1a using Kruskal-Wallis test. We found a significant difference (p 0.05) between the different grades by both classifications for ADC using the Kruskal-Wallis test. For b=150 and 400, there is a significant difference between F1 and F2 using the Mann-Withney test.Conclusion: In these initial results, it seems possible to differentiate moderate degree (F0-F2) of liver fibrosis in patients with chronic hepatitis C using DCE and DWI MRI.

C-033 Diagnostic value of SPIO-mediated breath-hold black blood fluid attenuated inversion recovery (BH-BB-FLAIR) imaging in patients with hepatocellular carcinomas M. Matsushima, S. Naganawa, H. Ogawa, T. Komada, S. Ishigaki, H. Kawai, K. Suzuki, H. Satake, S. Ito, M. Ikeda; Nagoya/JP (matsu_masa@hotmail.com)

Purpose: To assess the value of adding the breath-hold black-blood fluid attenu-ated inversion recovery (BH-BB-FLAIR) sequence with a small motion-probing gradient (b=10 s/mm2) using superparamagnetic iron oxide (SPIO) to the present SPIO-mediated studies for detecting hepatocellular carcinomas (HCC). A FLAIR pulse was used to suppress the signals from cysts. A low b-value was aimed to suppress the signal of vessels while providing higher signal to noise compared to high b-value diffusion weighted image. SPIO reduced the signal in normal liver parenchyma and most benign lesions.Methods and Materials: The data of 21 patients with 32 nodules of HCC, which were diagnosed by CT arterioportography (CTAP) and CT during hepatic arteriogra-phy (CTHA), were reviewed. Pre- and post-SPIO-mediated scans were performed, and images were divided into two sets. One (not included BH-BB-FLAIR set) was included pre- and post- dual-echo T1-, T2-, and post-T2*-weighted images and the other was added the Post-SPIO BH-BB-FLAIR image to the former set. 6 radiolo-gists individually interpreted these image sets and sorted the confidence levels for the presence of HCC. Area under the receiver operating characteristic (ROC) curve (Az) was calculated for each set.Results: The preliminary ROC analysis showed higher Az values when the included BH-BB-FLAIR set was interpreted (0.88) than when the not included BH-BB-FLAIR set was interpreted (0.84).Conclusion: Combined interpretation of post-SPIO BH-BB-FLAIR image and the SPIO-mediated images was expected to have higher performance for the detec-tion of HCC. The scan time is only 24s, and so this sequence can easily be added to the protocols.

C-034 Low-dose hepatic perfusion CT using a low tube voltage technique and an adaptive noise reduction filter Y. Yanaga, K. Awai, T. Nakaura, M. Imuta, T. Namimoto, Y. Yamashita; Kumamoto/JP

Purpose: To investigate the feasibility of low-dose hepatic perfusion CT using a low tube-voltage technique and an adaptive noise reduction filter.Methods and Materials: Thirty patients underwent serial dynamic CT on a 64-detector scanner. Half of them underwent standard-dose (p-A) and the other half low-dose (p-B) scanning. The scan parameters for p-A (p-B) were detector col-limation 8 x 5 mm (4 x 10 mm), 120 kV (80 kV), 200 mAs (150 mAs), scan cycle 3 sec/cycle, and scan duration 60 sec. We applied an adaptive noise reduction filter for images obtained under p-B. In both protocols, 15 g of iodine were administered over 10 sec. The image noise on the liver parenchyma and the maximal attenuation value of the aorta and liver were measured and 2 radiologists evaluated the image quality of the perfusion images using a 3-point scale.Results: The radiation doses for p-A and p-B were 236 and 54 mGy, respectively. The image noise for p-A and p-B was 9.78 and 10.25, respectively (t-test, p = 0.80). The maximal attenuation values for the liver and aorta in p-A were 89.8 and 321.9 HU, respectively, and for p-B they were 127.9 and 532.6 HU. All attenuation values were statistically significantly higher in p-B than p-A (p=0.03 and 0.04). The visual score for p-A and p-B was 2.4 and 2.1, respectively, with no significant difference (Mann-Whitney U test, p=0.29).Conclusion: As the image quality of low-dose hepatic perfusion CT was comparable to standard-dose scans, low-dose scanning is feasible.

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C-035 Multidetector CT angiography in the evaluation of potential living donors for liver transplantation: Single center experience in China Z. Zhuang1, J. Xu1, Y. Cheng2, L. Qian1, H. Gong1, W. Chai1, Q. Li1; 1Shanghai/CN, 2Taiwan/CN (zhiguozhuang@163.com)

Purpose: To evaluate relevant arterial, hepatic and portal venous anatomy by using multidetector CT angiography in potential living liver donors.Methods and Materials: 102 consecutive potential liver donors underwent CT angiography in the arterial, portal and hepatic venous phases with a sixteen-row CT scanner. All source images and reconstructed images were evaluated for anatomy of hepatic vasculature by an experienced radiologist and a surgeon in consensus. The anatomic variants of arterial system, portal venous system, and hepatic veins were characterized according to the classification system of Michels, Akgul, and Nakamura, respectively. CT finds were compared with the results of surgery in 42 donors who were all performed right hepatic lobectomy.Results: Of 102 candidates, 63 had type I, eight type II, 12 type III, three type IV, 11 type V, two type VI, two type VIII, and one type IX hepatic arterial anatomy. According to the classification of the portal venous system created by Akgul, type A was seen in 81 subjects. Type B, type C, and type E was revealed in 15, four and two subjects, respectively. According to the classification of the right hepatic drainage pattern by Nakamura, type 1 drainage was seen in 71 subjects (69.6%), type 2 was present in 22 candidates (21.6%), and type 3 in nine subjects (8.8%). CT angiography findings were confirmed in all donors who were operated on.Conclusion: Multidetector CT angiography can successfully show the relevant hepatic vascular anatomy in potential liver donors.

C-036 Small hypoechoic nodules in cirrhotic patients with previously treated HCC: Analysis of non-enhancing nodules at contrast-enhanced-US L. Tarantino1, I.F.M. Sordelli2, A. Schiano1, G. Francica3; 1Frattamaggiore/IT, 2Naples/IT, 3Casoria/IT (luciano_tarantino@fastwebnet.it)

Purpose: To analyze small hypoechoic nodules (SHNs) showing absence of en-hancement at contrast-enhanced-ultrasound (CEUS) in cirrhotic patients previously treated for hepatocellular carcinoma (HCC).Methods and Materials: 215 cirrhotic patients with HCC treated with surgery (19) and/or percutaneous ablation (192) and/or chemoembolization (44) were prospectively studied with US every two months (follow-up range: 10-32 months; median: 20 months). All new SHNs were studied with CEUS. Nodules showing early arterial enhancement (EN) at CEUS were considered recurrent HCCs. Non-enhancing nodules (NEN) underwent fine needle biopsy. HCC-histologically negative nodules were followed-up with US every two months. Increasing in size at follow-up was considered specific for recurrent HCC. Follow-up results were compared to FNB results.Results: 78 SHNs (size range: 7-20 mm; mean: 15 mm) were detected at US in 65 patients within 4-24 months (mean: 12 months) after previous HCC treatment. CEUS showed 52/78 (67%) ENs (diameter range 9-20 mm; mean: 16 mm). 26 NENs (diameter range: 7-13 mm) underwent FNB that showed HCC in 11/26 (42%) cases. 15/26 (68%) cases of “cirrhosis” at histology were followed-up (4-24 months; mean: 12 months). 7/15 nodules increased in size within 4-8 months and underwent thermal ablation. 5/15 did not change size and are still on follow-up. 3/14 nodules were no more detectable at subsequent US follow-up controls.Conclusion: Over 2/3 of SHNs in the clinical setting of cirrhotic patients with previ-ously treated HCC showed early arterial enhancement at CEUS. All NENs were 13 mm in size. Almost 1/3 of NEN (31% in our experience) could not be malignant

(regeneration nodules?) and even disappear at follow-up control.

C-037 Fatty metamorphosis in hepatocellular carcinoma (HCC): Comparison with MR dynamic enhancing study on HCC diagnosis Y.-J. Chen, T.-S. Jaw, T.-J. Hsieh, Y.-T. Kao; Kaohsiung/CN (HHSOOOO@gmail.com)

Purpose: To evaluate the characteristics and diagnostic effect of fatty metamor-phosis in hepatocellular carcinoma (HCC).Methods and Materials: The retrospective study enrolled 145 patients with liver tumors, including 94 HCCs, 13 regenerative nodules, 30 hemangiomas, and 8 metastastic tumors. All patients received the routine MR examinations in a 1.5 T MR scanner, which the routine sequences including in-phase and out-of-phase axial images, and contrast-enhanced dynamic axial images. The visible signal drop in tumor on out-of-phase (OP) images compared with in-phase image was defined as fatty metamorphosis. Increasing signal intensity on contrast-enhanced arterial phase, decreasing signal intensity on contrast-enhanced venous phase, and OP

signal drop in each lesion were recorded and statistical analyzed. Furthermore, the fatty metamorphosis change of HCCs were assayed to correlate with tumor size, patient’s age, sex, and the clinical underlying conditions (hypertension, diabetes, alcoholism, HBV or HCV carrier, alpha-FP level in blood).Results: The MR HCC diagnosis rate was improved in sensitivity, the positive and negative predictive values, as well as area under receiver operating characteristic (ROC) curve, by detecting OP signal drop combination with dynamic enhancing study. Totally 49 HCCs (52.1%) depicted fatty metamorphosis on chemical shift image. The data assay showed no size predominance and no predictive factor in the presentation of HCC fatty metamorphosis.Conclusion: In our study, the fatty metamorphosis was noted in the majority of HCCs on the chemical shift images and independent on several clinical factors. Using dual echo technique combine with dynamic enhancing study could improve the HCC diagnosis.

C-039 Predictive value of Tc-99m galactosyl human serum albumin (GSA) hepatic SPECT on the assessment of functional recovery after partial hepatectomy H. Wakamatsu1, S. Nagamachi1, S. Kiyohara1, S. Fujita1, K. Kamimura1, S. Futami1, R. Nishii2, S. Tamura1; 1Miyazaki/JP, 2Moriyama/JP

Purpose: In our previous study presented at ECR 2007, we reported that T1/2 was able to predict post operative function recovery as well as HH15, LHL15, and GSA-Rmax. As a second report, we calculated total hepatic GSA clearance (TCl), residual GSA clearance (RCl) total GSA-Rmax (TGSA) and residual GSA-Rmax (RGSA) using a hepatic SPECT analyze software developed by Dr. N. Shuke. The purpose of this study was to evaluate the usefulness of TCl, RCl, TGSA and RGSA to predict postoperative hepatic function recovery observing serum albumin and ChE. We compared T1/2, HH15, LHL15, and ICG15.Methods and Materials: We performed 99mTc-GSA liver scintigraphy before op-eration in 43 patients. Each patient was administered 185 MBq of 99mTc-GSA by intravenous injection. Dynamic images were taken immediately after administer-ing 99mTc-GSA for 40 minutes. SPECT image was obtained to make a functional mapping and TCl, RCl, TGSA and RGSA were calculated. We investigated the postoperative recovery days of serum albumin (rec-Alb), cholinesterase (rec-ChE), and 1 and 3 months after albumin (1M-Alb, 3M-Alb), cholinesterase (1M-ChE, 3M-ChE). We compared these predictive values for assessing postoperative liver function recovery.Results: We found significant correlation between RCl, RGSA and rec-Alb, rec-ChE, 1M-Alb, 3M-Alb, 1M-ChE and 3M-ChE and they were more significant than other parameters, T1/2, HH15, LHL15 and ICG15.Conclusion: Residual GSA clearance calculation using 99mTc GSA-SPECT was effective to predict postoperative liver function recovery, and it should be added before partial hepatectomy.

C-040 Optimal contrast dose for depiction of hypervascular hepatocellular carcinoma at hepatic dynamic CT using a 64-detector CT scanner Y. Yanaga, K. Awai, T. Nakaura, T. Namimoto, Y. Yamashita; Kumamoto/JP

Purpose: To investigate prospectively the optimal contrast dose for the depiction of hypervascular hepatocellular carcinoma (HCC) during the hepatic arterial phase (AP) at hepatic dynamic CT using a 64-detector CT.Methods and Materials: The study included 135 patients (mean, 66.1 years) with known or suspected HCC; all underwent dynamic CT on a 64-detector scanner. CT scans depicted 71 hypervascular HCCs in 47 patients. AP scanning was started 18 sec after triggering (threshold, 150 HU). The patients were randomly assigned to 3 protocols. We delivered a contrast dose of 450-, 525-, and 600 mgI per kg weight (BW) over 30 sec in protocols A, -B, and -C, respectively. We measured the tumor-liver contrast (TLC) during AP and the results were compared using the performed Turkey-Kramer test. Two radiologists qualitatively evaluated tumor conspicuity during AP using a 3-point scale and the results were compared using Steel-Dwass test.Results: The TLC in protocols A, -B, -C was 27, 38, and 52 HU, respectively; the difference was significant between protocols A and -B (p=0.05), protocols A and -C (p 0.01), and protocols B and -C (p=0.02). In qualitative analysis of tumor conspicuity, mean score for protocols A, B, and C was 1.6, 2.3, and 2.7, respectively, and there was a significant difference between protocols A and -B and protocols A and -C but not between protocols B and -C.Conclusion: A total iodine dose of 525 mg or more per kg BW should be admin-istered for the good or excellent depiction of hypervascular HCC.

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C-041 Focal contrast enhancement on hepatic CT in superior vena cava obstruction syndrome: Analysis of 12 cases L. Tang, X.P. Zhang, Y.S. Sun, J. Li, N. Wang, K. Cao; Beijing/CN (dr_alex@263.net)

Purpose: To investigate the imaging features of abnormal focal contrast en-hancement (FCE) on hepatic CT in patients with superior vena cava obstruction syndrome (SVCOS).Methods and Materials: Twelve patients with SVCOS enrolled into the study. The superior vena cava (SVC) was compressed by four lung cancers, four metastatic lymph nodes, two thymomas, and two NHL. The location, number, contour, and size of FCE areas on CT were observed, and the blood-supply collaterals were traced. The narrowing of SVC was divided into three degrees (slight, medium and severe), and the correlation between SVC compression and FCE was evaluated through follow-up.Results: The SVCs were severely compressed in 9 cases, and slight compression occurred in 3 cases. A total of 20 FCEs in 12 cases were detected and all located at the left lobe of liver, among which 5 cases located at S2, five cases located at S4, and 2 cases located at S2+S4. Fourteen FCEs appeared as irregular and 6 as round nodules. Fifteen FCEs displayed nonuniform enhancement with central high density and peripheral low density. All of the 12 cases manifested blood-sup-ply collateral vessels, which originated from internal thoracic veins (9 cases) and periesophageal veins (3 cases). Among the 6 follow-up cases, two SVC compres-sions relieved and the FCEs disappeared or diminished, two SVC compressions aggravated and the FCEs enlarged.Conclusion: The FCE on hepatic CT in patients with SVCOS has special imag-ing features and its size can change following the alteration of degree of SVC obstruction.

C-042 A new prognostic index of cirrhosis progression: CT and MR imaging findings and clinical correlation E. Filograna1, L. Bonomo1, V. Vilgrain2; 1Rome/IT, 2Clichy/FR (enricafilograna@gmail.com)

Purpose: To determine the role of lean body mass index, expressed as psoas muscle transversal diameter/height (PTD/H), obtained using CT and MR imaging, in predicting clinical evolution of compensated cirrhosis. The purpose was also to compare this index with the morphological criteria (caudate lobe, segment IV, liver and spleen volumes) showed as possible prognostic factors in cirrhotic patients.Methods and Materials: Seventy-two CT and ten MR abdominal imaging stud-ies were retrospectively reviewed in 82 patients with Child-Pugh grade A and B cirrhosis. All patients were followed up clinically for an average of 16 months. CT and MR images were employed to determine psoas muscle transversal and lon-gitudinal diameters, as well as to measure the volume of caudate lobe, segment IV, liver and spleen.Results: During follow-up in patients with progressive cirrhosis (n=34), PTD/H and volume indexes of liver and segment IV decreased significantly (P 0.0001, 0.02 and 0.01, respectively). PTD/H was significantly smaller (P 0.0001) in patients with ascites than in cirrhotic patients who did not present this complication. The volume indexes of the spleen and caudate lobe appeared bigger in presence of ascites (P=0.03 for both values).Conclusion: Lean body mass index, evaluated as PTD/H, was related to progres-sion of clinical severity of cirrhosis (Child-Pugh grade). This index previewed, as well as hypertrophy of spleen and of caudate lobe, ascites outcome after a 16 months follow-up time. Atrophy of the liver and segment IV also correlated with cirrhosis progression.

C-043 Contrast-enhanced behaviour at very low MI CEUS of a large series of hepatic adenoma V. Cantisani1, P. Ricci1, M. D’Onofrio2, F. Calliada3, D.V. Sahani4, E. Pagliara1, U. D’Ambrosio1, R. Passariello1; 1Rome/IT, 2Verona/IT, 3Pavia/IT, 4Boston, MA/US (vito.cantisani@uniroma1.it)

Purpose: To describe contrast-enhanced behaviour of histological proven hepatic ad-enomas studied with low- mechanical index (MI) contrast-enhanced US (CEUS).Methods and Materials: From 2003 and 2006, the databases of four academic hospitals (Università degli studi di Verona, Mass General, Harvard Medical School, Boston, Policlinico Umberto I, University La Sapienza, Rome, Policlinico San Matteo, Pavi) were reviewed to evaluate imaging finding of the patients with histological proven hepatic adenoma (HA) studied with contrast-enhanced US (CEUS) at low-mechanical index (0.1-0.2). Size, color-doppler US, and CEUS behaviour were analyzed.

Results: 21 patients (18 females, 3 males; age range: 25-71 years) with 28 adenomas (mean diameter: 3.5 m) were identified. All of the 28 lesions showed an early and strong enhancement (10-19 sec) during the arterial phase. All the lesions showed no portal vein supply; thus 21 out of 28 appeared isoechoic, while 7 out of 25 appeared hypoechoic during the portal and 20 isoechoic and 8 mildly hypoechoic during the late phases.Conclusion: CEUS is an effective technique in identifying micro and macrovascular characteristics of hepatic adenoma. Typically hepatic adenoma shows early (10-18 seconds) and homogeneous enhancement during arterial phase, hysoechogenicity or mild hypoechogenicity during the portal phase, remaining slightly hypoechoic or isoechoic during the late phase.

C-044 Arterial complications of adult liver transplantation: Correlation of CT appearances with angiography and surgery I. Martineau, S. Awad, A. Sarina, D. Castaing, R. Adam, D. Samuel, M.-F. Bellin; Villejuif/FR (imane.karout@free.fr)

Purpose: To assess the ability of multidetector CT angiography (CTA) to character-ize arterial complications of adult liver transplantation.Methods and Materials: From February 2005 to July 2007, 185 adult patients underwent liver transplantation in our center. We reviewed CT angiography (40-detector-row, MIP reconstructions) and Doppler sonography examinations (resistive index, morphological data) in 15 cases of arterial complication (11 patients). We correlated CTA findings with angiography and peroperative findings obtained during surgical anastomotic repair.Results: In 9 cases of early complication (3 thromboses, 2 stenoses, 2 plicatures, 1 pseudoaneurysm, 1 arterial bleeding) CTA findings were compared with surgery. In 6 cases of delayed complications (3 thromboses, 3 stenoses) CTA findings were compared with angiography. CTA yielded a correct diagnosis in 15/15 cases. There were 2 false negatives with Doppler sonography. 2 plicatures, detected on CTA and confirmed by surgery, were misdiagnosed as stenoses on sonographic and angiographic examinations. For delayed complications, MIP and multiplanar recon-structions were more precise than angiography to analyze collateral arteries.Conclusion: Multidetector CT angiography with MIP and multiplanar reconstruc-tions is a precise imaging modality for characterizing arterial complications of adult liver transplantation and may obviate the need to perform angiography.

C-045 Diffusion-weighted MRI in focal hepatic lesions: The validation study R. Maksimovic, M. Dunjic Kratovac, G. Lilic, L. Lazic; Belgrade/RS (rmaksimovic@yahoo.com)

Purpose: The study was design to determine if there is a difference between ap-parent diffusion coefficient (ADC) values using MRI with different b factors and to compare ADC values of hepatic lesions.Methods and Materials: The study included 63 patients with focal hepatic lesions, 52 men (82.5%), age 62.1 9.8 years. Fourteen patients (22.2%) had hepatocellular carcinoma (HCC) confirmed on surgery, 16 patients (25.4%) were with hepatic metastatic colorectal tumours confirmed on previous surgery, 17 patients (26.9%) with cavernous haemangioma and 16 patients (25.4%) with hepatic cysts based on clinical manifestation, ultrasound/CT/MRI and follow-up results. MRI was performed with 1.5 T scanner, with a body coil using EPI sequence with two and tree b values: 0, 500 and 0, 400, 800 s/mm2. ADC values were measured in all the lesions, as well as a ratio between the ADC value of the liver and the lesion.Results: ADC values when two and three b values were used were respectively: HCC patients 1.4 0.4 (1.4 0.4), metastatic tumours 2.0 0.4 (2.2 0.1), haeman-gioma 2.7 0.3 (2.6 0.1), cysts 3.4 0.2 (3.1 0.03) s/mm2, with no statistically significant difference (F=1.2, p 0.05), although the images were more homoge-neous when three values were applied. However, there was statistically significant difference between the ADC values of the lesions (F=39.2, p 0.01). Furthermore, the ratio liver/lesion in the patients were 1.01, 1.61, 0.48 and 0.41, respectively, with significant difference between the patients with malignant and benign lesions (F=11.2, p 0.05).Conclusion: ADC values based on three b values offer more homogenous images and can differentiate focal liver lesions.

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C-046 Hypervascular focal liver lesions: Enhancement evaluation in the dynamic and hepatobiliary phases after Gd-EOB-DTPA, comparison with MDCT L. Grazioli1, M. Bondioni1, B. Frittoli1, L. Romanini1, A. Filippone2; 1Brescia/IT, 2Chieti/IT

Purpose: To evaluate MDCT and MR enhancement of hypervascular focal liver lesions in the arterial and in the hepatobiliary phases after 0.025 mmol of Gd-EOB-DTPA.Methods and Materials: 38 cirrhotic and 30 non cirrhotic patients with 129 hypervascular proven lesions were evaluated (85 HCC, 18 FNH, 13 HA, 13 Mts). Qualitative analysis considered: CT/MR lesions’ arterial enhancement; lesions/liver enhancement in the hepatobiliary phase at 10’-20’-30’; quantitative analysis: mean % of parenchymal enhancement in the different phases.Results: On CT and MR respectively, HCC showed moderate enhancement in 33.3 vs 25.7%, discrete in 46.9 vs 35.9%, notable in 16.6 vs 38.4%. In the hepatobili-ary phase, HCCs were ipointense in 94.1% at 10’, 92.9.% at 20’-30’. On CT, FNH enhanced notably in 66.6%, discretely in 22.2%, moderately in 11.1%, and on MR, notably in 100% of lesions. In the hepatobiliary phase, FNH was isointense in 77.7%, hyperintense in 22.3%. On CT, HA enhanced moderately in 53.8%, discretely in 38.4%, and on MR discretely in 76.9%, notably in 7.6%. In the hepatobiliary phase, 100% of HA were ipointense. On CT and MR respectively, metastases showed discrete enhancement in 61.5, vs 76.9%, notable in 38.4 vs 23%. On MR all lesions appeared already notable after 10’. The mean % of parenchymal enhancement was 57.2, 59.5, and 60.2% at 10’, 20’, 30’, more elevated in non cirrhotic patients.Conclusion: MR arterial phase after Gd-EOB-DTPA was superior to arterial MDCT. Parenchymal enhancement at 10’ was judged descrete/notable in 97% of cirrhotic and in all 100% non cirrhotic patients.

C-047 To compare the imaging findings of different MR liver specific contrast materials (Gd-BOPTA, Gd-EOB-DTPA, Mn-DPDP, and ferumoxides) in the diagnosis of hepatic adenoma (HA) and liver adenomatosis (LA) L. Grazioli1, G. Morana2, G. Schneider3, M. Kirchin4, M. Bondioni1; 1Brescia/IT, 2Treviso/IT, 3Homburg a.d. Saar/DE, 4Milan/IT

Purpose: To compare the imaging findings of different MR liver specific contrast materials (Gd-BOPTA, Gd-EOB-DTPA, Mn-DPDP, and ferumoxides) in the diagnosis of hepatic adenoma (HA) and liver adenomatosis (LA).Methods and Materials: 44 patients with 156 nodules of either HA or LA were evalu-ated. MR imaging was performed in all patients before/after Gd-BOPTA, in 15 patients before/after Gd-EOB-DTPA, in 28 patients before/after Mn-DPDP, and in 21 patients before/after ferumoxides. T1wGRE and T2wDP images were acquired as appropriate. Comparison was performed for 156 lesions after Gd-BOPTA, 56 lesions after Gd-EOB-DTPA, 108 lesions after Mn-DPDP, and 74 lesions after ferumoxides.Results: Pre-contrast T1w and T2w images revealed variable enhancement pat-terns: 132/156 lesions on precontrast T2w images and 127/156 lesions on precon-trast T1w images were either slightly hyperintense or hypointense; the remainder were isointense or not visible. Dynamic evaluation after Gd-BOPTA and Gd-EOB-DTPA revealed homogeneous (149/156) or heterogenous (7/156) hyperintensity in all cases. In the delayed hepatobiliary phase, all 156 lesions after Gd-BOPTA and all 56 nodules after Gd-EOB-DTPA appeared hypointense; conversely, all 108 HA after Mn-DPDP appeared iso or hyperintense. After ferumoxides administration, 56/74 HA showed homogeneous or heterogenous signal drop.Conclusion: Gd-BOPTA and Gd-EOB-DTPA are more appropriate contrast agents than ferumoxides and Mn-DPDP for the characterization of HA. Dynamic phase imaging provides information on the hypervascular nature. Hypointensity in the hepatobiliary phase after Gd-BOPTA and Gd-EOB-DTPA permits HA to be differentiated from FNH.

C-048 Usefulness of multiplanar reconstruction with multislice computed tomography to assess hepatocellular carcinoma response after transcatheter arterial chemoembolization T.V. Bartolotta, V. Macchiarella, V. Bova, A. Taibbi, M. Galia, F. Cannizzaro, M. Midiri; Palermo/IT (tv_bartolotta@yahoo.com)

Purpose: To evaluate the role of multiplanar reconstructions with multislice com-puted tomography (MSCT) in the assessment of transcatheter arterial chemoem-bolization (TACE) therapeutic response of hepatocellular carcinoma (HCC).Methods and Materials: Fifty-seven patients (40 men, 17 women; mean age: 68.3 years) with unresectable HCC (size range: 1.3-8 cm, mean: 3.4 cm) treated with TACE underwent multiphase MSCT one month after treatment. To evaluate the necrosis rate of the lesion on MSCT, the following formula: (unhenancing area)+(iodized oil

retaining areas)/(total tumoral area) x 100 was calculated on three different planes (axial, coronal, and sagittal) choosing the slice in which the tumor showed the larg-est diameter and the mean value was obtained. Complete necrosis was considered when no enhancing portion within or at the margin of the nodule during the hepatic arterial phase was detectable, with homogeneus pattern of lipiodol deposition within the lesion, and still viable tumoral tissue when an irregular peripheral-enhancing focus in the arterial phase with irregular or incomplete lipiodol retention were observed. Patients with a necrosis rate 50% were considered as responder, whereas patients with rates 50% were considered as non-responder.Results: At MSCT, one month after treatment, 35/57 (61.4%) patients were considered as responders, whereas 22/57 (38.6%) patients were considered as non-responders. On the basis of the one-month MSCT features, 19 patients underwent a second TACE session. Survival rates were 73.1% and 53.6% at 12 and 20 months, respectively.Conclusion: Multiplanar reconstructions with MSCT are suitable for the evaluation of the efficacy of TACE for HCC.

C-049 Clinical usefulness of free-breathing (FB) MR techniques in abdomen J. Kim, H. Eun, S. Hong, G. Kwon, D. Deuk Lin Choi, J. Hwang; Seoul/KR (junghkim@medimail.co.kr)

Learning Objectives: To learn the variable application of FB MR technique in abdominal MR imaging. To compare three FB MR sequences in the evaluation of focal liver lesions. To assess the clinical usefulness of FB MRCP in non-cooperative patients compared with breath-hold MRCP.Background: We can use the FB techniques including navigator-triggered pro-spective acquisition correction (PACE) and respiratory-triggered (RT) technique in abdomen. FB techniques applied in turbo spin-echo (TSE), half-Fourier single-shot turbo spin-echo (HASTE), and MRCP. Forty-nine patients with 86 focal liver lesions (56 malignant and 30 benign) underwent liver MRI with three different FB sequences. 48 non-cooperative patients (13 malignant and 35 benign) who could not hold their breath underwent FB MRCP with TSE using PACE. The FB MR techniques and clinical usefulness of FB MRI in abdomen are described and illustrated.Procedure Details: All forty-nine patients with 86 focal liver lesions underwent liver MR imaging with three different FB sequences, including PACE-TSE, PACE-HASTE, and RT-TSE. All 48 non-cooperative patients underwent breath hold (BH) thick-sec-tion MRCP, BH thin-section MRCP, and FB MRCP with TSE using PACE.Conclusion: PACE-TSE sequence provides the best diagnostic performance for lesion detection and characterization. FB MRCP significantly improves diagnostic performance compared with the conventional BH MRCP. FB techniques are useful in abdominal MRI and MRCP, especially non-cooperative patients.

C-050 Associations between hepatic FDG accumulation and variables K. Kamimura1, S. Fujita1, H. Wakamatsu1, R. Nishii1, S. Nagamachi1, Y. Umemura1, M. Ogita1, T. Fujimoto1, M. Nakajo2; 1Miyazaki/JP, 2Kagoshima/JP (kiyohisa@mp.0038.net)

Purpose: Liver demonstrates heterogeneous FDG uptake pattern and sometimes shows abnormally increased uptake even though there is no malignant tissue. Recently, FDG uptake in liver was correlated with fasting blood glucose (FBS) and fatty liver reported. The aim of this study was to evaluate the relationships of hepatic FDG uptake with fatty liver, FBS and other biochemical data.Methods and Materials: The FDG-PET imaging was performed in 101 consecutive patients for cancer screening. The FDG uptake in liver was analyzed semiquantita-tively using region of interest (ROI) on transaxial image at umbilical level and the computed tomography (CT) number (Hounsfield units; HU) in liver was analyzed at the same level. Multiple stepwise regression analysis was used to define the best predictors of the hepatic standardized uptake value (SUV) about the CT numbers in the liver, FBS and other biochemical data, i.e., aspirate aminotransferase (AST), alanine aminotransferase (ALT), -glutamyl trasopeptidase ( -GT), triglycerides (TG), HDL cholesterol (HDL-CHO), total protein (TP), total bilirubin (T-BIL), alkaline phosphatase (ALP), and uric acid (UA).Results: The average of hepatic SUV evaluated by FDG-PET showed a significant positive relationship with the BMI (P 0.0012) and TG (P 0.0127), and negative relationship with HDL-C (P 0.0033). On the other hand, hepatic FDG uptake was not related with the CT number of the liver, FBS, and several hepatic enzymes, AST, ALT, -GT, HDL-CHO, TP, T-BIL, ALP, and UA.Conclusion: The SUV of liver was positively correlated with BMI. This result suggests that we need careful interpretation of the liver in a case of high BMI patient.

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C-051 Detection of hepatocellular carcinoma with ferucarbotran-enhanced MR imaging: Efficacy of delayed fat-suppressed T1-weighted imaging C.-T. Chou1, R.-C. Chen2, W.-T. Chen2, J.-M. Li2, H.-K. Wu1; 1Chang-Hwa/CN, 2Taipei/CN (96888@cch.org.tw)

Purpose: To evaluate the effectiveness of delayed fat-suppressed T1-weighted imaging (FS-T1WI) in the detection of HCC in the Ferucarbotran-enhanced MR imaging.Methods and Materials: Thirty patients underwent Ferucarbotran-enhanced MR imaging with 35 confirmed HCCs included in this prospective study. Two image sets were prepared and two radiologists independently reviewed two reading sessions; set A without and set B with the postcontrast delayed FS-T1WI. HCCs were confirmed by operation (n=4), biopsy (n=28) and follow-up studies for at least one year (n=3).Results: The CNRs significantly increased from -1.2 7.5 to 12.7 7.3 on the post-contrast delayed FS-T1WI, but only slightly increased from 12.2 10.3 to 15.5 12.2 on the postcontrast T2WI (p 0.001). The SNRs decreased on T1WI and T2WI for the liver parenchyma and T2WI for the HCCs and slightly increased on T1WI for the HCCs. 29 HCCs were detected on the set A and 35 nodules were identified with the postcontrast delayed FS-T1WI on the set B. The detection rate was statistically significantly increased by reading postcontrast delayed FS-T1WI (p =0.014).Conclusion: Due to better CNR on the delayed postcontrast FS-T1WI and increas-ing in the detection rate, the postcontrast delayed FS-T1WI is recommended as one of the routine protocols for HCC detection.

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C-052 Extrapancreatic lesions associated with autoimmune pancreatitis: Prevalence, distribution and image findings Y. Fujinaga, M. Kadoya, K. Ueda, M. Momose, S. Kawakami, S. Yamazaki, T. Hatta, H. Hamano, S. Kawa; Matsumoto/JP (fujinaga@hsp.md.shinshu-u.ac.jp)

Learning Objectives: To clarify involved organs accompanied by autoimmune pancreatitis (AIP). To characterize the diagnostic imaging features of the extra-pancreatic lesions of AIP.Background: AIP is a unique form of chronic pancreatitis characterized by au-toimmune inflammatory process in which prominent lymphocytes, IgG4-positive plasma cells and fibrosis are found. Recently, IgG4-positive plasma cells have been demonstrated in various extrapancreatic lesions in AIP patient, suggesting AIP might be a part of the systemic disease. Diagnostic imagings play an important role in the evaluation of the lesions.Procedure Details: We retrospectively reviewed diagnostic images of 85 AIP patients who underwent CT, MRI or Gallium scintigraphy between September 1994 and August 2007. Diagnosis was based on the diagnostic criteria for AIP proposed by the Japanese Pancreatitis Society. Extrapancreatic lesions were confirmed by biopsy or improvement of image findings after steroid therapy. AIP was accompanied by extrapancreatic lesions (91.7%), such as hilar lymphadenopathy (79.7%), bile duct lesions (77.2%), peripancreatic or paraaortic lymphadenopathy (57.6%), lung lesions (47.2%), lachrymal and salivary grand lesions (46.9%), retroperitoneal fibro-sis (19.8%), and renal lesions (12.9%). CT and MR imaging showed enlargement or deformity of the involved organs. The lesions revealed abnormal signal intensities at MR images. Gallium scintigraphy demonstrated increased uptake of the lesions. We exhibit diagnostic images of various extrapancreatic lesions of AIP.Conclusion: Because AIP might be a systemic inflammatory disease, recognition of the prevalence, distribution, and image features of various involved organs will be helpful in developing the differential diagnosis for lesions involving the pancreas.

C-053 Imaging analysis of intrapancreatic vein under various pathological conditions of the pancreas with multi-detector CT scanning N. Hongo, H. Mori, R. Takaji, Y. Yamada, S. Matsumoto; Oita/JP

Learning Objectives: 1. To demonstrate the changes in the intrapancreatic vein under pathologic conditions. 2. To explain the utility of the assessment of the intra-pancreatic vein in the diagnosis or treatment of various pancreatic diseases.Background: Multiphase study using multi-detector CT enables detailed assess-ment of the peripancreatic veins or the intrapancreatic veins. Knowledge of the pathological findings of these veins in the light of normal venous anatomy provides key information in the diagnosis of the various pancreatic diseases.Imaging Findings: Abnormal dilatation of the intrapancreatic veins can be ob-served in cases with neuroendocrine tumors, serous cystic tumors, hypervascular metastatic lesions and portal vein stenosis or occlusion at collateral pathways. Obscuration of the intrapancreatic veins can occur in cases with acute pancreatitis and pancreatic carcinomas.Conclusion: 1. Neuroendocrine tumors have a strong tendency to have abnormally dilated intrapancreatic veins as drainage vessels. 2. To differenciate cystic neoplasm of the pancreas, dilatation or early visualization of the surrounding intrapancreatic vein can be a key in the diagnosis of serous cystic tumors. 3. Obscuration of the intrapancreatic veins in acute pancreatitis can help in predicting the severity of pancreatitis.

C-054 Pancreatic adenocarcinoma: Facing the beast F. González, J. Izquierdo, C. Juanco, G. Blanco, M. Gutierrez, M. Lopez, M. Silvan; Santander/ES (radgsf@humv.es)

Learning Objectives: Overview of the prevalence of pancreatic adenocarcinoma, tumor biology and genetics, and treatment options. Overview of imaging modalities and protocols for optimizing imaging with MDCT and MR. Overview of endoscopic ultrasound (EUS)and its role in diagnosis. Evidence-based review of the perfor-mance of each technique in staging.Background: Pancreatic adenocarcinoma is a widespread and difficult cancer to diagnose and treat, despite improved understanding of biology, improved imaging, and improved surgical expertise.The exact diagnosis and staging condition therapeutics options. An exact pre-surgi-

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cal stage is essential for the surgeon. Imaging methods (MDCT, MR, EUS) allow us approach to an exact, but difficult stage.Procedure Details: We provide an overview of pancreatic adenocarcinoma: prevalence, genetics, biology, tumor markers, treatement strategy and survival. We also describe the imaging optimized prococols, MDCT, MDCT-PET, MR, EUS, used to evalate the pancreas. We emphasize on angio CT or angio MR to determine vascular involvement; multiplanar views are also important. We analyze the critical preoperative imaging findings: Size, location, vascular involvment, metastases. Evidence-based review of performance of modalities for local and distant staging is made. All the findigns are illustrated with clinical examples of routine and chal-lenging cases. Finally, we stablish an algorithm for the imaging diagnosis.Conclusion: Pancreatic adenocarcinoma is a widespread and difficult cancer to diagnose and treat. It was considered as a beast by clinicians and surgeons. The radiologist has an important weapon to win the “ beast”, early diagnosis and cor-rect staging. MDCT, dynamic MR, Cholangio MR and EUS are the tools that help to establish an early and exact diagnosis.

C-055 Cystic pancreatic masses: A systematic approach based on imaging findings F. González, A. Fernandez, C. Juanco, R. Pellon, J. Izquierdo, M. Lopez, M. Silvan; Santander/ES (radgsf@humv.es)

Learning Objectives: To learn the spectrum of cystic lesions of the pancreas.To recognize and categorize imaging findings of cystic lesions of the pancreas.To understand the diseases by correlating radiological and pathologic studies of cystic lesions of the pancreas.Background: Cystic neoplasm of the pancreas is a common type of lesion of a different nature (benign and malignant tumor, inflammation, infectious, congenital, etc.). Its diagnosis and characterization finally determine its management and patient prognosis. We illustrate with sample cases of imaging findings the clues that allow a definitive diagnosis.Imaging Findings: Sonography, CT and MR before and after intravenous contrast are analyzed (Cystic wall, contrast enhancement, intracystic material, borders, pancreatic duct dilatation, vascular encasement, etc.).We illustrate with examples imaging findings in the most frequent cystic pancreatic masses (pseudocysts, serous cyst adenomas, mucinous cystic neoplasms, solid and papillary epithe-lial tumors, intraductal papillary mucinous tumors of the pancreas, pancreatic abscess).The differential diagnosis of cystic lesions of the pancreas include the spectrum from non-tumoral processes to malignancies and peripancreatic cystic masses. Pseudocysts are the most common cystic lesions of the pancreas and the most likely diagnosis after pancreatitis. Mucinous and serous cystic tumors of the pancreas affect middle-aged women. Serous cystic tumors are benign, while mucinous have malignant potential.Intraductal papillary mucinous tumors of the pancreas are often associated with pancreatic duct dilatation.Conclusion: A correct approach to cystic pancreatic masses based on imaging findings is essential to stablish the exact diagnosis. Imaging findings and exact characterization determine management and patient prognosis.

C-056 Primary and secondary pancreatic lymphoma: Diagnostic criteria on imaging C. Triantopoulou, Z. Touloumis, P. Porfyridis, I. Fagadaki, P. Maniatis, I. Siafas, J. Papailiou, C. Dervenis; Athens/GR (chatri@mycosmos.gr)

Learning Objectives: To demonstrate the imaging features of primary and sec-ondary pancreatic lymphoma and present differential diagnostic criteria from other pancreatic tumors.Background: Primary pancreatic lymphoma (PPL) is an extremely rare potentially treatable disease and can present as an isolated mass mimicking pancreatic carcinoma. On the other hand, secondary invasion of the pancreas from other involved structures such as stomach, duodenum, small intestine or peripancreatic and retroperitoneal lymph nodes, is more common. Computed Tomography (CT) is a well-established procedure to evaluate pancreatic masses. Our experience concerning a large number of patients is presented.Imaging Findings: Two different patterns of the disease were recognized: a local-ized well-circumscribed tumoral form and a diffuse enlargement with infiltration or replacement of most of the pancreatic gland. According to established diagnostic criteria, PPL was diagnosed when there was no hepatic, splenic or thoracic involve-ment, the leukocyte count in the peripheral blood was normal and lymph nodal involvement was confined to the peripancreatic region. Neither calcifications nor necroses were seen in the involved pancreatic areas, while pancreatic duct showed no dilatation. Vessels encasement or stenosis was seen in a minority of cases. Ac-

curate diagnosis of lymphoma was possible by imaging in all the patients and was confirmed in a small number of cases by CT-guided FNA or FNB.Conclusion: Accurate differentiation of pancreatic lymphoma from pancreatic adenocarcinoma is very important as treatment and prognosis differ significantly. In most cases diagnosis is possible by CT obviating the need for interventional procedures.

C-057 Imaging of hypervascular pancreatic lesions: Endocrine tumor and others S. Arizono, H. Isoda, Y. Maetani, Y. Hirokawa, K. Shimada, K. Togashi; Kyoto/JP (arizono@kuhp.kyoto-u.ac.jp)

Learning Objectives: To describe the spectrum of hypervascular tumors and tumor like conditions affecting the pancreas. To illustrate the imaging findings of these lesions with histopathological correlation. To provide examples of differential diagnosis.Background: Although endocrine tumor represents most of hypervascular tumors arising in the pancreas, there are many other hypervascular tumors and inflam-matory, vascular, or congenital lesions, which sometimes mimic endocrine tumor. In this exhibit, we present various imaging findings of hypervascular tumors and tumor like conditions, and discuss their differential diagnosis.Imaging Findings: We retrospectively evaluated dynamic enhanced CT, MR, and angiographic images of patients with hypervasucular pancreatic lesions. Endocrine tumor typically presents as a well-circumscribed hypervascular lesion. Metastatic tumor, especially from renal cell carcinoma, is often depicted as a hypervascular nodule, mimicking endocrine tumor. Serous cystadenoma is generally well en-hanced, but can be differentiated from other lesions by the finding of high signal intensity on heavily T2-weighted image. Accessory spleen can be diagnosed using SPIO-enhanced MRI or 99mTc colloid scintigraphy. Ductal adenocarcinoma and acinar cell carcinoma present as hypervascular tumor on rare occasions. There are other hypervascular pancreatic and peripancreatic lesions illustrated, including mixed exocrine-endocrine carcinoma, hemangioma, arteriovenous malformation, rare form of autoimmune pancreatitis, and gastrointestinal stromal tumor of the duodenum.Conclusion: Knowledge of imaging findings of various hypervascular pancreatic lesions is important for differential diagnosis.

C-058 Cystic pancreatic tumors: Imaging review with pathologic correlation C.A. Silva1, M. Pimenta2, A. Salgueiro1; 1Matosinhos/PT, 2Porto/PT (catarina.silva.hph@gmail.com)

Learning Objectives: 1. Illustrate the spectrum of imaging findings of cystic pancreatic tumours with pathologic correlation. 2. Review the diagnostic strengths and limitations of each imaging modality in the differential diagnosis of pancreatic cystic lesions.Background: Cystic tumours of the pancreas are uncommon, contributing to 2% of all pancreatic tumours. The discovery of a cystic lesion in the pancreas represents a challenge to the radiologist. Despite the recently increased attention to pancreatic cystic neoplasms, there continues to be inadequate appreciation of the different types of cystic tumours, with improper diagnostic and therapeutic approaches.Procedure Details: The accurate diagnosis of a cystic pancreatic tumour requires different imaging techniques, including US, CT, MRI and MRCP. Because most of the presenting symptoms are abdominal symptoms, ultrasonography is generally the first imaging technique used to detect and sometimes characterize the features of these tumours, especially when classic features are present. MDCT is however superior in the depiction and characterization of these lesions, and is the preferred modality in the initial workup of pancreatic cystic tumours. MRI with MRCP accu-rately depicts the cystic morphology and can be a useful problem-solving technique when an evaluation of the ducts and its relationship with the lesion is needed.Conclusion: A definitive preoperative diagnosis of pancreatic cystic tumours is often possible when the lesion has a typical radiological appearance, but in many cases characterization with imaging alone is difficult.

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C-059 Cystic lesions of the pancreas: CEUS, MRI and MRCP features G.A. Zamboni, M. D’Onofrio, G. Carbognin, A. Casarin, L. Bassi, R. Pozzi Mucelli; Verona/IT

Learning Objectives: To describe CEUS and MRI findings that allow characteriza-tion of cystic pancreatic lesions.Background: MRI and MRCP are established imaging modalities for studying cystic pancreatic lesions. MRI of the pancreas includes baseline T1-weighted gradient-Echo (GE) fat saturated and T2-weighted fast spin-echo, and postcontrast T1W-GE or volume interpolated breath-hold examination sequences. MRCP is performed with 2D or 3D sequences. MRI and MRCP provide useful information on the cystic lesion, the pancreatic ducts and their relationship. The study of the pancreas is a recent promising application of CEUS. CEUS of the pancreas with second-generation contrast media shows marked early parenchymal enhancement followed by progressive washout; the peculiarity of CEUS is that contrast-enhanced phases can be followed dynamically.Imaging Findings: Pseudocyst: Intralesional debris, well depicted by CEUS and MRI, can render the diagnosis difficult; CEUS easily demonstrates the absence of intralesional enhancement. Serous cystadenoma: CEUS, thanks to its better spatial resolution, shows enhancement of intralesional septa improving identification of microcystic features. Mucinous cystadenoma: CEUS helps identify vascularization of parietal nodules and septa, which aids in the differential diagnosis with pseudo-cysts. Depicition of calcifications is easier with CEUS than with MRI. IPMT: CEUS can show the vascularization of intraductal papillary tumoral vegetations. MRCP can easily demonstrate the communication between the tumor and the pancreatic duct, allowing a final diagnosis of branch-duct IPMT; MRI is also more useful when studying multiple lesions.Conclusion: This comprehensive review addresses the topic of MRI and CEUS of cystic pancreatic lesions, discussing examination techniques and imaging findings.

C-060 Intraductal papillary mucinous neoplasm of the pancreas: Assessment of the grade of dysplasia using multislice CT H. Ogawa, S. Itoh, M. Ikeda, K. Suzuki, S. Naganawa; Nagoya/JP

Purpose: To evaluate the capabilities of multislice CT in determining the grade of dysplasia of intraductal papillary mucinous neoplasm (IPMN).Methods and Materials: Our institutional review board approved this research, with informed consent from the patients waived. Two radiologists blinded to the grade of dysplasia of IPMN retrospectively evaluated CT images of 61 consecutive surgi-cally resected tumors (26 adenomas, 15 noninvasive carcinomas, and 20 invasive carcinomas) in patients who underwent multiphase contrast-enhanced CT with 0.5-mm or 1-mm collimation. The findings were statistically analyzed by univariate and multivariate analyses, with the optimal cutoff levels of each continuous parameter determined by generating receiver operating characteristic curves.Results: The following findings showed significant differences between the three groups: maximum diameter of the main pancreatic duct (MPD), size of the largest mural nodule in the MPD and/or cystic lesion, abnormal attenuated area in the surrounding parenchyma, calcification in the lesion, protrusion of the MPD into the ampulla of Vater, and bile duct dilatation. An MPD diameter of 6 mm or more, a mural nodule of 3 mm or more, and an abnormal attenuated area were independently predictive of malignancy. A mural nodule in the MPD of 6.3 mm or more and an abnormal attenuated area were independently predictive of invasion. According to these criteria, the sensitivity, specificity, and accuracy for identifying malignancy and invasion were 83%, 81%, and 82% and 90%, 88%, and 89%, respectively.Conclusion: Multislice CT is useful for distinguishing between adenoma, nonin-vasive carcinoma, and invasive carcinoma in patients with IPMN.

C-062 Predictive value of multidetector CT in determination of pancreatic cancer resectability S. Mazzeo, C. Cappelli, V. Battaglia, D. Caramella, G. Caproni, A. Belcari, S. Pallocci, C. Bartolozzi; Pisa/IT (novetrequarti@yahoo.it)

Purpose: To evaluate the role of multidetector CT in determining surgical resection of pancreatic cancers.Methods and Materials: We evaluated 134 patients with ductal adenocarcinoma of the pancreas submitted to surgery. At CT we considered the following criteria: vascular encasement, retroperitoneal infiltration, metastases and peritoneal carcinosis. Three different groups of patients were identified: resectable cases (all negative findings); questionably resectable cases (absence of carcinosis and

metastases, suspicion of retroperitoneal infiltration or venous infiltration eligible to vascular resection); and unresectable cases (metastases and/or carcinosis and/or arterial encasement and/or venous encasement not eligible to vascular resection associated with retroperitoneal macroinfiltration). Pathologic reports and intraopera-tive findings were considered as the “gold standard”.Results: Pancreatic therapeutic resection was performed in 74 patients, while 60 patients were submitted only to an intra-operative exploration. In detecting metas-tases, carcinosis, vascular infiltration and retroperitoneal infiltration CT obtained a sensitivity of 88%, 17%, 89% and 87% respectively. At CT, resectability was judged absolute in 50/74 cases and questionable in 24/74: among the latter, 20 patients underwent surgery. In analysing the 110 patients judged at CT either as resectable (50) or unresectable (60), we obtained a sensitivity of 90%, a specificity of 91%, with a PPV of 95% and a diagnostic accuracy of 86%.Conclusion: Multidetector CT provides valuable preoperative prediction of surgical resectability not only in patients with negative findings but also in the cases judged as questionably resectable.

C-063 Multidetector CT in the assessment of neuroendocrine pancreatic neoplasms nature: Comparison between CT and histological findings S. Mazzeo, V. Battaglia, C. Cappelli, D. Caramella, G. Caproni, D. Campani, F. Mosca, C. Bartolozzi; Pisa/IT (novetrequarti@yahoo.it)

Purpose: To evaluate the role of multidetector CT in assessing the nature of neuroendocrine pancreatic neoplasms.Methods and Materials: We analysed 49 lesions in 30 patients (3 patients had, respectively, 15, 5 and 2 lesions). CT was performed before and after iodine contrast medium intravenous administration (5 ml/min) in early arterial (15”), pancreatic (30”), venous (70”) and delayed (180”) phases. Three different post-contrasto-graphic patterns were identified: pattern A, including lesions with “early arterial” or “pancreatic” enhancement (15”/30”) and rapid wash-out; pattern B, including lesions with early wash-in and no wash-out; pattern C, including lesions with en-hancement in the “delayed” phase. CT findings were compared with pathological results after surgery.Results: At histopathology, 23 lesions resulted to be benign, 18 malignant and 8 borderline. At CT, 27/49 lesions showed pattern A (average dimension-a.d 13 mm); at histopathology 22/27 resulted to be benign (diameter 2 cm in all cases), 1 malignant (12 mm) and 4 borderline (all 2 cm). Patterns B and C included 22/49 lesions (a.d. 41 mm); at histopathology 17/22 resulted to be malignant ( 2 cm in all cases, a.d 46 mm), 4 borderline (a.d. 19.4 mm) and 1 benign (15 mm). Pattern A showed a positive predictive value (PPV) of 82% in predicting neuroendocrine pancreatic lesions benignity, while patterns B and C showed a PPV of 77% in predicting malignancy.Conclusion: Multidetector CT may suggest the nature of neuroendocrine pancreatic neoplasms on the basis of their enhancement pattern. Our series confirm that le-sions with diameter greater than 2 cm should be suspected to be malignant.

C-064 Complete pancreatic encasement of portal vein: Circumportal pancreas S.-Y. Song1, J.-Y. Oh1, Y. Kim2, O.-K. Cho1, B.-H. Koh1; 1Seoul/KR, 2Kuri/KR (songsy@hanyang.ac.kr)

Purpose: To evaluate the incidence of the complete encasement of the portal vein by the pancreas (CEP), not widely known variation, and to propose its develop-mental hypothesis.Methods and Materials: Two radiologists interpreted MDCT data of 500 consecu-tive patients by consensus. Patients were divided into 5 groups according to the degree of pancreatic encasement as seen on axial scan just cranial to the conflu-ence of the splenic vein into portal vein (portal confluence) (Group I, encasement 90°; II, 180°; III, 70°; IV, 360°; V, CEP). We measured the vertical distance

between the centers of SMA orifice and portal confluence. It was compared with the degree of encasement.Results: CEP (Group V) was discovered in 17 patients (3.4%). The remaining were 162 (32.4%) in group I, 202 (40.4%) in II, 61 (12.2%) in III, and 58 (11.6%) in IV. The mean distance between SMA and portal confluence was -4.38 10.61 mm in I, -2.30 10.49 mm in II, -1.82 11.13 mm in III, -6.74 10.37 mm in IV, and -14.29 12.49 mm in V. The distance was significantly lower in groups IV and V than in others (p 0.05). The increments of group III to IV and IV to V decreased in proportion to the distance (p 0.05).Conclusion: CEP was not a rare finding. There was a tendency for higher degree of encasement of the portal vein by the pancreas in subjects with lower-lying portal confluence. This suggests that the portal venous anatomy may be associated with the development of this variation.

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Abdominal Viscera (Solid Organs)

Miscellaneous

C-065 How diffusion and relaxation related factors influence MR signal intensity (SI): A pictorial introduction to MR diffusion weighted imaging (DWI) studies F. Pasquinelli1, L. Mannelli1, G. Belli1, L. Politi2, F. Vizzutti1, U. Arena1, S. Colagrande1; 1Florence/IT, 2Milan/IT (filippopasquinelli@yahoo.it)

Learning Objectives: To describe and exemplify the main factors which influence SI value on DWI.Background: MR-DWI allows measuring the degree of diffusion of water molecules in biological tissues in vivo. Several diffusivity-related factors such as temperature, b value, diffusivity, pseudodiffusion, macroscopic motion and T2-weighted SI value can influence DW-SI and should be taken into consideration for an accurate inter-pretation of resultant images. Such factors are of common knowledge, but they have never been collectively explained, mathematically described nor interrelated.Imaging Findings: The effects of the above reported factors on DWI have been exemplified and described using in vitro/in vivo illustrative examples. Apparent diffusion coefficient (ADC), shine-through, and lack of mobile spin effect have been defined and analyzed in various experimental and clinical conditions. Finally, pseudodiffusion and macroscopic motion have also be defined and examined to show how T2-weighted SI value and non diffusional intra-voxel-incoherent-motion can affect the DWI.Conclusion: In DWI, SI is mainly influenced by diffusivity, pseudodiffusion, mac-roscopic motion and T2-weighted intensity value; the latter is to be considered as an index of the amount of free water molecules in the examined voxel. ADC is a scalar quantitative parameter insensitive to T2-effects and incorporating all the intra-voxel-incoherent-motion. To obtain an image which is truly representative of diffusivity, a high b value is required and ADC maps should be calculated. In fact, high b values increase the “weighting” in D, and determine a progressive reduction of T2, pseudodiffusion and macroscopic motion effects. ADC mapping, instead, eliminates only T2 outcome.

C-066 Imaging of extranodal lymphoma from head to toe L.F.P. Gonçalves, S.C.P.C. Dias, H. Torrão, S. Kurochka, A.C. Costa, C. Leite, V. Mendes; Braga/PT (l.f.p.goncalves@gmail.com)

Learning Objectives: We review the imaging of 170 patients with pathologically proven extranodal lymphoma, consecutively evaluated at our institution, and high-light its clinical importance.Background: Extranodal location occurs in 40% of lymphoma, most frequently in children, immunocompromised and non-Hodgkin’s lymphoma. Extranodal lesions may locate in virtually any organ, simulating neoplastic or infectious disorders. It is an adverse prognostic factor and affects therapeutic decisions. Imaging determines the extent of lymphoma and assists in treatment planning, thus playing a major role in staging and in follow-up. Computed tomography (CT) is the imaging technique most widely used and has diagnostic and therapeutic impact. Diffuse infiltration and microscopic lymphoma remain a challenge to all imaging modalities.Imaging Findings: We describe radiography, CT, ultrasound, mammography and magnetic resonance (MR) imaging of diverse extranodal lymphomas. The most common location was the abdomen. CT adequately demonstrated respiratory, gastrointestinal, genitourinary and focal hepatic and splenic lymphoma. MR was superior in depicting musculoskeletal, subdural, epidural and bone marrow involve-ment. Breast lymphoma was best portrayed by ultrasound and mammography. Diagnosis is not always straightforward, so useful differential features were also pointed out.Conclusion: CT adequately depicts most of the extranodal lymphoma; other im-aging modalities have specific indications. These imaging findings are important staging and management determinants.

C-067 State-of-the-art imaging of spleen J. Quintero, C. Roqué, D. Hernández, A. Olazábal, I. Guasch; Badalona/ES (jcquintero.germanstrias@gencat.net)

Learning Objectives: The purpose of this exhibit is: 1) to illustrate the spectrum of congenital and acquired abnormalities in the spleen; 2) to determine the current role of ultrasound, CT and MR imaging in the detection and characterization of focal spleen lesions.

Background: The spleen has the same relationship to the circulatory system as the lymph nodes have to the lymphatic system. A wide range of splenic variations and abnormalities can affect the spleen and may be detected on abdominal imaging, while one simultaneously evaluates the remaining intraabdominal structures.Imaging Findings: We reviewed retrospectively 43 patients with normal splenic variations and with abnormalities of the spleen diagnosed in our institution. We present a comprehensive algorithmic approach to diagnose various abnormali-ties of the spleen: 1) normal anatomy and congenital variations (5); 2) traumatic conditions (9); 3) vascular affections (5); 4) infections (4); 5) cysts (3); 6) benign neoplasms: hemangioma (3), hamartomas (1), lymphangiomas, and inflammatory pseudotumor (1); 7) malignant neoplasms: primary, lymphoma (5), and metastasis (4); 8) miscellaneous conditions: sarcoidosis (1), amyloidosis (1), thorotrastosis, and extramedullary hematopoiesis (1).Conclusion: The normal anatomy, congenital variations, and acquired abnormali-ties such as those resulting from trauma, infection, infarction, cysts, and neoplasm were discussed. US, CT and MR imaging all play an important role in the detection and characterization of focal splenic lesions, and with sufficient clinical information, they enable the differential diagnosis of these lesions.

C-068 Virtual non-contrast (VNC) dual energy scanning with dual source CT (DSCT): Initial experience R. Ma1, C. Liu1, J. Chen2; 1Jinan/CN, 2Peking/CN (mary.03@163.com)

Learning Objectives: To investigate the ability and value of VNC in depicting abdominal anatomic structures and lesions.Background: VNC-indicated, no real non-contrast scan (RNC), non-contrast im-age is generated from contrast images by dual energy (DE) scan with DSCT. This is a new technique of DSCT, introduced in 2006. Between April and August 2007, DE abdomen scan was done on 30 patients (35-72 years) who were suspected of abdominal lesions and referred for routine abdomen CT scan on DSCT (SOMATOM Definition): portal venous phase, with 120 Kv single tube scan in arterial and paren-chyma phase, DE protocol:1.2 mm collimation, Iopromide (Ultravist 300,Schering) at an injection rate of 3.5 ml/s. Portal venous phase was obtained in about 60 s after contrast injection. In kernel D30f, 80 kV, 140 kV and merged images were generated, respectively, with 5.0 mm slice thickness and increment. The 80 and 140 Kv images were imported into the DE VNC software on Syngo workstation and VNC images were acquired as gray scale images.Imaging Findings: High-density spots of contrast agent on contrast images were removed after DE VNC postprocessing and the VNC image was just like the routine RNC image, except for the relatively high-image noise. The following were structures and lesions whose outlines and normal/abnormal densities could be distinguished on VNC images: portal vein and its main branches (27/30), major anatomatic structures in the abdomen (30/30), stones in the gallbladder and renal pelvis (5/5), calcifications in the vascular wall (10/10), cysts in the liver and kidney (6/6), tuomr in the liver and kidney (5/5), which were confirmed by contrast scan or surgery.Conclusion: VNC image could play a part of RNC role in appreciating main ana-tomic structures and lesions of the abdomen.

C-069 Comprehensive approach to inflammatory pseudotumor: Various radiologic manifestations that mimic malignant tumors S. Park1, H. Kim2, J. Lee2, J. Kim2, K.-S. Cho2; 1Ulsan/KR, 2Seoul/KR (pksungbin@paran.com)

Learning Objectives: To identify inflammatory pseudotumor with a variety of morphologic characteristics and clinical manifestations that mimic malignant tumors; to identify the sites at which inflammatory pseutotumor occurs, unusually as well as usually.Background: Inflammatory pseudotumor is an enigmatic entity of unknown etiol-ogy, usually seen in the lung and in the orbit of children and young adults. This disease entity may demonstrate a variety of morphologic characteristics and clinical manifestations that mimic malignant tumors. It has also been described in nearly every site in the body. When the imaging findings and occurring sites are unusual, the diagnosis of inflammatory pseudotumor can be extremely difficult. Therefore, unusual image features and occurring sites as well as usual features should be taken into account.Imaging Findings: We demonstrate the findings on usually occurring sites (air-ways including lung and heads, and neck including orbit, cavernous sinus, nasal cavity, brain, sphenoid sinus, temporal bone) and unusually occurring sites (liver, pancreas, small and large intestine, retroperitonum, pelvic mass, inguinal, adre-nal gland, kidney, bladder). Findings on heart and breast involving inflammatory pseudotumors are also demonstrated.

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Conclusion: Familiarity with the imaging features and manifestations of unusual inflammatory pseudotumor as well as with the usual features will facilitate prompt and accurate diagnosis and treatment.

C-070 The rebirth of venous imaging: MR venography using a blood pool contrast agent and time resolved imaging J.R. Bottomley; Sheffield/UK (john.bottomley@sth.nhs.uk)

Learning Objectives: 1) To understand the advantages of using blood pool con-trast agent in vascular imaging, including additional (free) central venous, deep and superficial venous evaluation. 2) To understand the adjustments necessary for MR imaging parameters to achieve high-quality MR venography examinations. 3) To understand the common clinical senarios in which MR venography plays an important role. 4) To understand the advantages of dynamic, time-resolved MR venography and their clinical application.Background: Venous imaging has for a long time suffered from problems of contrast dilution in capacious veins, centrally directed blood flow not allowing peripheral vessel opacification, and blind spots on ultrasound. Blood pool contrast agents and high-resolution MR sequences have allowed many of these issues to be ad-dressed once and for all. In addition dynamic MR venography using time-resolved sequences has allowed physiological reverse venous filling to be demonstrated without resorting to external compression.Imaging Findings: Examples include 1) painful vulval varicose veins due to dynamic reversed filling of the left ovarian vein filling pelvic collaterals and left vulval varices. 2) Central venous obstruction with collateral filling demonstrated on dynamic MRV. 3) Incidental extensive IVC thrombosis identified on MRA using blood pool contrast agent.Conclusion: Blood pool contrast agents have widely opened the door to accurate and more extensive venous imaging. When combined with dynamic time-resolved MR, physiologically significant reflux can be demonstrated.

C-071 The spaces of the retroperitoneum: A pictorial review A. Almeida, M. Castro, J. Loureiro, B. Viamonte, J.M. Pereira; Porto/PT (atbalmeida@sapo.pt)

Learning Objectives: The aim of this study is to make a review of the complex anatomy of the retroperitoneum, illustrating it with a series of cases of pathologic processes that spread along the boundaries of the different retroperitoneal com-partments.Background: The anatomy of the retroperitoneum is somewhat complex. The retro-peritoneal space, between the diaphragma and pelvic brim, is divided into anterior pararenal, perirenal and posterior pararenal compartements by the anterior and posterior renal fascia. Some authors include a distinct fourth compartment, called the retroperitoneal vascular compartment. These different compartments encompass fat and organs and structures of the gastrointestinal, urinary and vascular systems. Diseases of the retroperitoneal space usually originate from these organs. Some pathologic processes may spread to different retroperitoneal spaces or the pelvis, making it difficult to locate its origin.Imaging Findings: This educational exhibit presents a comprehensive review of the anatomy of the retroperitoneal space. We use the imaging features of the most frequent retroperitoneal pathologic processes, including inflammatory processes and fluid collections (pancreatitis, pielonephritis, diverticulitis, perforating ulcera, abcesses, hematomas, etc.), as well as solid processes (primary and metastatic tumors, lymphoma, fibrosis, etc.) to illustrate the location of the different compart-ments on MDCT, emphasizing the importance of its knowledge to make an accurate localization of a variety of pathologies.Conclusion: Familiarity with the anatomic boundaries of the retroperitoneal space and the pathways of disease spread allows the radiologist to make an accurate evaluation of disease extension, helping in management decisions.

C-072 Imaging findings in alveolar hydatid disease M. Inal, C.K. Parsak, M. Celiktas, S. Soyupak, F. Binokay, E. Akgül, K. Bıçakçı, E. Aksungur, M. Oguz; Adana/TR (minal@cu.edu.tr)

Learning Objectives: To present imaging findings of alveolar echinococcosis. To describe the role of different imaging methods in both diagnosis and demonstrating the preoperative disease extent. To discuss the role of preoperative percutaneous image-guided interventions in alveolar echinococcosis of the liver.Background: Alveolar Hydatid Disease (AHD) caused by the larvae of echino-coccus multilocularis is rarely seen when compared with Cystic Hydatid Disease

(CHD) caused by echinococcus granulosus. Although liver is the most commonly involved organ by both parasites, geographic distribution, symptoms, imaging find-ings, clinical course and the treatment of AHD and CHD are different. Although histopathologically a benign disease, AHD shows the characteristics of a malignant disease: destructive tissue growth, invasion of adjacent organs or structures, and distant dissemination. US, triphasic CT, MRI, PTC, ERCP, percutaneous porto-graphic findings in 6 cases of alveolar echinococcosis (5 in liver, 1 in gastrosplenic ligament) are presented in this study.Imaging Findings: Large (range: 8-19 cm), infiltrating tumorlike mass with irregular margins was seen in all (100%) cases. Amorphous calcifications (83%), vascular invasion (83%), enhancement of fibroparasitic component (67%), intrahepatic bile duct invasion (67%), and central cystic areas (34%) were detected with different imaging methods. Percutaneous biliary drainage (two cases) and percutaneous abscess drainage (one case) were performed in 50% of cases, preoperatively.Conclusion: In case of a large, infiltrating, heterogenous liver mass containing calcifications and showing enhancement with contrast material, AHD should be considered in the differential diagnosis. Preoperative percutaneous interventions can facilitate subsequent surgery in cases with biliary obstruction or centropara-sitic abscess.

C-073 Familial amyloidosis (Portuguese variant): Spectrum of manifestations J. Pires, M. França, M. Teixeira Gomes, R. Themudo, J. Reis; Porto/PT (jmigps@gmail.com)

Learning Objectives: Illustrate the range of manifestations and complications of this entity, endemic in Northern Portugal.Background: Familial amyloid (Portuguese variant) is a hereditary disease, char-acterized by the extracellular deposition of insoluble material, namely the transport protein transthyretin (TTR), causing organ dysfunction. TTR is synthesized primar-ily in the liver and its gene is located on chromosome 18. Clinical manifestations are wide-ranging. Most cases are associated with cardiac, nerve, gastrointestinal tract, carpal ligament and vitreous corpus involvement. Complications are common and reflect the system affected. Definitive diagnosis is made by demonstration of Congo red binding material in a biopsy specimen and positive immunostaining (antiserum against TTR).Treatment depends mainly on hepatic transplantation, which slows down the pro-gression. It should be performed early in the course of disease. Prognosis depends on the TTR variant and organs involvedImaging Findings: Common imaging findings observed are: presence of pacemak-ers in plain films of chest (associated or not with cardiomegaly); significant amount of intestinal gas in abdominal plain films; sonographic signs of nephropathy and neurogenic bladder; sonographic features of carpal tunnel syndrome; neuropathic changes in the joints of the lower limb. Several other manifestations and complica-tions are illustrated.Conclusion: At a time when the mobility of people in Europe is a reality, it is necessary to be familiar with the manifestations of this entity, so that we can alert the clinician of the diagnosis, and not confuse it with other pathologies that could result in erroneous treatment.

C-074 Understanding dissemination of diseases in the peritoneal cavity: What we should know about peritoneal anatomy A.G. Spanoudaki, N.A. Courcoutsakis, G.E. Daskalogiannakis, P.K. Prassopoulos; Alexandroupolis/GR (ncourcou@med.duth.gr)

Learning Objectives: To illustrate the normal appearance of peritoneal ligaments and mesenteries on cross-sectional imaging. To describe the interconnections between peritoneal viscera along peritoneal reflections and the peritoneal cav-ity subdivisions. To understand the key role of anatomy in the dissemination of peritoneal diseases.Background: The peritoneum is reflected over abdominal organs to form a series of folds known as ligaments, mesenteries, and omenta. These peritoneal reflections attach, interconnect, suspend, and supply the abdominal viscera. They govern the pathways of intra- or extra-peritoneal diseases dissemination and affect the peritoneal fluid circulation along with bowel peristalsis, hydrostatic pressure and gravity gradients.Imaging Findings: Although not directly visible on imaging, the twelve major peritoneal ligaments and mesenteries can be identified by their typical position, organ relationships, fatty composition and anatomic landmarks provided by their constituent vessels. Peritoneal folds involved by edema, inflammation or neoplastic infiltration alter their composition, become thickened and are directly recognized on imaging. Peritoneal cavity is subdivided into multiple compartments and recesses

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by peritoneal reflections, which are visualized when distended by fluid. These subdivisions provide the anatomic basis for localization of acsites, abscesses, seeded metastases and traumatic effusions. Multiplanar CT reconstructions and specific MRI sequences, including 3d FLASH and True-FISP sequences, are useful in demonstrating normal or infiltrated ligaments and mesenteries.Conclusion: Knowledge of the normal anatomy and, consequently, of the anatomic pathways for disease spread in the abdominal cavity is crucial in the main radiologi-cal analysis and differential diagnosis of peritoneal and mesenteric pathology.

C-075 Be mindful of melanoma R. Summerfield, G. Rylands, M. Goldstein, M. Metelko, N. Lane; Stoke-on-Trent/UK (summerstuff@yahoo.com)

Learning Objectives: To review the pathophysiology and staging of malignant melanomas. To review the spectrum of imaging findings of metastatic melanoma including its MRI characteristics.Background: When metastatic disease is found incidentally, melanoma can be overlooked in the ‘hunt’ for a primary tumour as the original lesion is rarely seen on imaging. Melanoma is unfortunately increasing in incidence. Current figures for the United Kingdom show a prevalence of 44 per 100000. Whilst only 4% have distant metastasis at presentation, there can be a long latent period between the original diagnosis and the development of metastasis. 30-40% of patients with melanoma will eventually die due to the cancer. When melanoma metastasises, it does so aggressively. It can spread by direct extension, blood or lymphatics to a wide variety of organs.Imaging Findings: We use multimodality imaging to illustrate the appearances of malignant melanoma in a variety of organs including the brain, bones, liver, spleen, gastrointestinal tract and the peritoneum. MRI images are reviewed which illustrate that melanoma metastasis are often high signal on T1 weighted sequences.Conclusion: Metastatic melanoma can spread to almost any organ. Whilst appear-ances can be variable, it does have some imaging features which can guide the radiologist when making a diagnosis. It should always be considered as a primary tumour and the patient examined accordingly.

C-076 Comprehensive review of the interfascial plane of the reteroperitoneum M. Kim, S. Lee, Y. Won, Y. Ku, K. Kim; Seoul/KR (sneaky0708@hanmail.net)

Learning Objectives: To review embryologenesis and anatomy of interfascial plane and spread pathways of various kinds of retroperitoneal pathologic entities with CT imaging.Background: Up to date, traditional compartmental anatomy does not completely explain the spread of fluid collections in the retroperitoneum. More recent works including embryologic, clinical considerations and anatomic dissections have modified the classic tri-compartmental model and introduce the concept of the interfascial plane. In this exhibit, we will describe the concept of expandable planes (interfascial plane) in which rapidly growing fluid collections may accumulate, by review of embryology and imaging findings. After reviewing records in the radiology database from January 2006 through June 2007, we identified 54 patients with various pathologic conditions involving interfascial planes on CT scan.Procedure Details: CT observations demostrated the rapidly accumulating fluid collections or hematoma tend to escape retroperitoneal site of origin into laminar variably fused and potentially expandable interfascial planes. Between these planes, potential communicating spaces exist. These are represented by retromesenteric plane (anterior fusion space), retrorenal plane (posterior fusion space) and lateral conal plane. Interfascial fluid collection can spread from the abdominal retroperi-toneum into the pelvis along retromesenteric plane and retrorenal plane that form the combined fascial plane at the level of the iliac fossa.Conclusion: The knowledge of embryology and anatomy of interfascial plane and their interconnection is helpful for the radiologist to determine the extent and spread pathways of the retroperitoneal disease.

C-077 Marginal zone B-cell non-Hodgkin lymphoma of mucosa-associated lymphoid tissue (MALToma) type: Imaging findings O. Maksimovic, W. Bethge, J. Pintoffl, M. Vogel, R. Bares, C.D. Claussen, M.S. Horger; Tuebingen/DE (Olga.Maksimovic@med.uni-tuebingen.de)

Learning Objectives: To illustrate the characteristic imaging findings of marginal zone B-cell lymphomas (MZL) of mucosa-associated lymphoid tissue (MALToma) type and to outline these findings in comparison with respective differential diag-noses. To make the reader familiar with the imaging features of this hematologic

disorder throughout different affected organs.Background: There are three types of marginal zone B-cell non-Hodgkin’s lympho-mas (NHL), splenic, nodal and mucosa-associated extra-nodal, which are each distinct clinicopathologic entities. Mucosa-associated lymphoid tissue neoplasms (MALToma) constitute approximately 5% of all NHLs. Systemic “B symptoms” are uncommon with MALToma and there is a rare association with nodal or medullar involvement ( 25%). Moreover, peripheral blood is usually not initially involved. As MALToma arise most frequently in various extra-nodal sites with approximately 51% of cases being in the gastrointestinal (GIT) tract, diagnosis is challenging. Further potential primary sites are the orbit and ocular adnexa, lung, skin, soft tissues, parotid gland, thyroid gland, thymus, Waldeyer's tonsilar ring, breast and pancreas.Imaging Findings: Imaging findings in 17 different patients with MALToma with different sites of involvement including scarcely involved organs such as ocular ad-nexa, parotid gland, skin, biliary tract, breast and Waldeyer´s tonsilar ring as well as lung and gastrointestinal tract are demonstrated comprising CT, MRT, PET-CT and ultrasound findings. Important differential diagnoses are outlined respectively.Conclusion: The awareness of potentially expected locations of MALToma com-bined with their incidence and imaging findings allows a more accurate diagnosis

of lesions suspicious of this disorder and, furthermore, helps to differentiate it from other abnormalities.

C-078 Fat only and water only gradient echo MR imaging of the abdomen. Part I: Basic concepts and imaging findings in the liver E.M. Merkle, D.I. Schulz, D.T. Boll, D. Marin; Durham, NC/US (elmar.merkle@duke.edu)

Learning Objectives: 1. To review the physics of a 2-point Dixon technique based on a breath-hold 3D T1-weighted gradient dual echo sequence. 2. To discuss and illustrate the most relevant applications of this technique in liver imaging.Background: Applying a 2-point Dixon method to a gradient dual echo sequence allows in the reconstruction of two additional data sets referred to as ‘water only’ (WO) and ‘fat only’ (FO) images. This exhibit will explain the underlying physics, illustrate the imaging appearance of diffuse and focal liver diseases, and highlight potential pitfalls on ‘fat only’ images due to T2* effects.Imaging Findings: WO images provide excellent suppression of fat signal, whereas FO images demonstrate signal intensity similar to the background noise for most abdominal organs. A notable exception is the increased signal intensity on FO images of fatty liver. Occasionally, this finding can also be seen in the liver and/or spleen of patients with iron storage disease due to iron-based magnetic susceptibil-ity effect. FO and WO images enable a definite diagnosis of increased liver content of both iron and fat. FO and WO increase the conspicuity of either fat-containing liver lesion or lesion in the setting of a diffuse fatty liver.Conclusion: WO images represent an alternative to pre pulse chemical shift fat saturated images. FO images may increase the reader’s confidence for the detec-tion and characterization of fat within abdominal tissues. FO and WO images may enable a definite diagnosis in patients with simultaneous hepatic storage of both iron and fat.

C-079 Fat only and water only gradient echo MR imaging of the abdomen. Part II: Extrahepatic imaging findings E.M. Merkle, D.I. Schulz, D.T. Boll, D. Marin; Durham, NC/US (elmar.merkle@duke.edu)

Learning Objective: To illustrate the most relevant extrahepatic imaging findings on 2-point Dixon fat only and water only images, with special emphasis on the gallbladder, pancreas, adrenals and kidneys.Background: With recent technological advances, 2-point water only (WO) and fat only (FO) Dixon images can be reliably acquired without additional data acquisition time. By providing additional information of tissue composition, WO and FO im-ages will probably become a routine part of every abdominal MR imaging protocol. Besides potential liver application, radiologists should familiarize themselves with major extrahepatic imaging findings on WO and FO images.Imaging Findings: WO and FO images can be useful in evaluating several gall-bladder pathologies, including cholecystitis, gallstone composition, and gallbladder carcinoma. WO and FO images are also beneficial in corroborating the diagnosis of pancreatic fatty replacement (either diffuse or focal), as well as several benign fat-containing neoplasm of the adrenals (i.e., adenoma, myelolipoma) and kidneys (i.e., angiomyolipoma).Conclusion: As an adjunct to in-phase and opposed-phase sequences, FO and WO images can be beneficial for a definite diagnosis of several extrahepatic abdominal disorders.

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C-080 Comparison of observer performance in a non-traumatic acute abdomen CT setting N.-H. Stauffer, A. Tempia, P. Rau, D. Guntern, N. Kotzampassakis, E. Melloul, C. Picht, T. Prot, S. Schmidt, C. Vallet, A. Denys; Lausanne/CH (stauffernh@hotmail.com)

Purpose: Emergency room reading performances have been a point of interest in recent studies comparing radiologists to other physician groups. Our objective was to evaluate and compare the reading performances of radiologists and surgeons in an emergency room setting of non-traumatic abdominal CTs.Methods and Materials: A total of ten readers representing four groups participated in this study: three senior radiologists and visceral surgeons, and two junior radiologists and surgeons, respectively. Each observer blindly evaluated a total of 150 multi-slice acute abdominal CTs. CTs were chosen representing established proportions of acute abdominal pathologies in an academic trauma center. Each answer was transformed into a score ranging from 0=all false to 3= all correct for further statistical evaluation. Gold standard was the intraoperative result and the clinical patient follow-up for non-operated patients. Significance was assumed at a p .05 level.Results: Senior radiologists had a mean score of 2.38 1.14 and junior radiologists a score of 2.34 1.14, whereas senior surgeons scored 2.07 1.30 and junior sur-geons 1.62 1.42. No significant difference was found between the two radiologist groups, but results were significantly better for senior surgeons as compared to junior surgeons and better for the two radiologist groups as compared to each of the surgeon groups (all p 0.05).Conclusion: Abdominal CT reading in an acute abdomen setting should continue to rely on an evaluation by a radiologist, whether senior or junior. Satisfying reading results can be achieved by senior visceral surgeons, but junior surgeons need more experience for a good reading performance.

C-081 Should splenic injuries be reclassified with multi-detector contrast-enhanced CT? R. Young, H. Hiller, J.-L. Cook; Swindon/UK (rdy44@doctors.org.uk)

Purpose: The classification of splenic trauma has been reviewed, suggesting that the current AAST (American Association for the Surgery of Trauma) criteria do not accurately predict the need for splenectomy. Therefore a new classification system has been proposed to utilize the improved diagnostic accuracy of contrast-enhanced multi-detector CT.Methods and Materials: Retrospective clinical and laboratory data were collected from 21 patients with splenic trauma between January 2003 and December 2006. The mechanism of trauma and interval between admission and splenectomy were also recorded. All patients underwent a contrast enhanced CT scan, usually within one hour of admission, using a Siemens Somatom Sensation 16. All CT scans were classified by a consultant radiologist, blinded to the outcomes, using both the AAST criteria and our own new classification system.Results: Eight patients underwent splenectomy within two hours of admission, and thirteen patients were managed conservatively. Using the AAST criteria, 2 out of 6 grade II lesions underwent splenectomy, and 4 out of 7 grade III lesions underwent splenectomy. Using the new classification system, 1 out of 7 grade II lesions had a splenectomy, and 5 out of 6 grade III lesions had a splenectomy. The three AAST grade III lesions, which were managed conservatively, would have been reclassified as grade II using the new classification system.Conclusion: Using the preliminary new classification system, the need for splenectomy was more accurately predicted compared with the traditional AAST criteria. This system is currently being assessed with a prospective randomized clinical trial.

C-082 A quantitative method for splenomegaly assessment by superparamagnetic iron oxide-enhanced MRI with SHU-555 A (Resovist®) M.L. Paolucci, S. Ciolli, L. Santoro, N. Villari, S. Colagrande; Firenze/IT (marialarapaolucci@libero.it)

Purpose: To assess malignant vs. non malignant splenomegaly, evaluating Signal Intensity Variation ( SI) of the parenchyma after Resovist® administration with a quan-titative method, based on the function of spleen reticuloendothelial system (RES).Methods and Materials: 19 patients without splenic pathology, 13 with malignant splenomegaly (diffuse involvement by 9 chronic lymphatic leukaemia and 3 lym-phoma, pathologically proven), 9 with non-malignant splenomegaly (chronic liver disease related) have been prospectively evaluated by 1.5-T MRI, body phased-ar-ray receive coil, GE-T1w/TSE-T2w sequences. After slow administration (0.5 ml/s)

of Resovist®, followed by 20 ml of saline-solution-flush, T1w sequences were repeated at 30-60-120”, and T1/T2w sequences at 10’. SI of the parenchyma was measured by 400 mm2 ROI (sd 20%) and normalised with SI of the muscle (N) in order to avoid the rescaling phenomenon: in all phases SI was formulated by [(SI-

post/SIpre)x (Npre/Npost)-1]x100. Statistical analysis was performed by paired t-test.Results: At enhanced 10’- T2w sequences, normalized mean SI was -46 13, -12 26, -47 6 in normal spleen, malignant splenomegaly, and non-malignant splenomegaly, respectively. Average parenchymal measurement identifies normal spleen and non-malignant splenomegaly, from malignant splenomegaly (99% confidence interval for p 0.01).Conclusion: In our series, normalised SI measurement after Resovist® allows for differentiating non-malignant from malignant splenomegaly due to leukaemia-lymphoma. In the latter patients, scarce negative enhancement seems related with poor RES activity due to diffuse parenchymal malignant involvement.

C-083 Iron distribution in the upper abdomen, bone marrow and myocardium in beta-thalasssemia major: Assessment with quantitative MR imaging O. Papakonstantinou, E. Alexopoulou, N. Economopoulos, K. Foufa, A. Katamis, V. Ladis, A. Gouliamos, N. Kelekis; Athens/GR (olypapak@hotmail.com)

Purpose: To investigate the correlation between the degree of hepatic, splenic, pancreatic bone marrow and myocardial siderosis, as expressed by T2 values of re-spective tissues in transfusion-dependent patients with beta thalassemia major.Methods and Materials: T2 relaxation rate values of liver, spleen, pancreas, VBM and myocardium were calculated in 68 consecutive patients with beta-thalassemia major and 10 healthy controls. Thirty-two patients were splenectomised. All MR imaging studies were performed at a single 1.5 T magnet, using a respiratory triggered 16-echo Carr-Purcell-Meiboom-Gill (CPMG) spin-echo sequence (TR: 2000 msec, TEmin: 5 msec, in 16 symmetrically repeatable echoes). Serum ferritin values close to the MR studies were recorded.Results: a) Hepatic T2 values were significantly decreased in all 68 patients, VBM T2 in 67 patients, pancreatic T2 in 36 patients and myocardial T2 in 51 patients. Splenic T2 was found decreased in 29 of 38 non-splenectomised patients and within normal limits in 9/38 patients. Noteworthy, splenomegaly was more common in patients with normal splenic T2. b) Hepatic siderosis correlated with splenic (r=0.63, p 0.001), VBM (r=0.52, p 0.001) but not with myocardial and pancreatic siderosis. Serum ferritin correlated with hepatic, VBM, splenic and myocardial T2.Conclusion: Although there are positive correlations between the degree of hepatic, splenic, VBM and cardiac siderosis, in beta-thalassemia major occasionally, iron distribution may follow unpredictable patterns such as normal signal of the spleen in the presence of siderotic liver, similar to primary hemochromatosis. MR imaging can be valuable in the follow-up of thalassemic patients and in elucidating iron kinetics.

C-084 Whole body MDCT in patients with multiple trauma: Is there still need for abdominal ultrasound follow-up studies?T. Meindl, M. Koerner, T. Vogl, M. Reiser, U. Linsenmaier; Munich/DE (thomas.meindl@med.uni-muenchen.de)

Purpose: Ultrasound serves as a diagnostic tool for follow-up examinations in patients with multiple trauma if admitted to an intensive care unit (ICU). This study evaluates the clinical impact of ultrasound follow-up after the introduction of multi-detector computed tomography (MDCT).Methods and Materials: 46 patients with multiple traumas referred to the emer-gency room and subsequent ICU admission were included. All patients underwent MDCT and follow-up abdominal ultrasound at 6 and 24 hrs after admission. Patients were grouped into group 1, normal abdominal MDCT scans and group 2, abdominal injuries indicated by MDCT. Medical records and radiological reports were evalu-ated for the diagnostic impact of follow-up abdominal ultrasound in comparison to MDCT. Changes of routine laboratory parameters within the first 24 hours on ICU and their impact on the use of abdominal ultrasound were evaluated.Results: Twenty-four out of the 46 patients had an unremarkable abdominal MDCT (group 1) but extra-abdominal injury, and 22 had traumatic abdominal organ lesions (group 2). Follow-up ultrasound detected no additional/secondary lesions in group 1 compared to initial MDCT, even when laboratory parameters (e.g. drop in hemoglo-bin) indicated hemorrhage. In group 2, ultrasound failed to reliably confirm MDCT findings. Ultrasound detected no additional/secondary lesions after MDCT.Conclusion: Follow-up ultrasound after whole body MDCT provides no additional information in patients with unremarkable initial CT. Follow-up ultrasound did not contribute substantial information in patients with MDCT-proven abdominal organ injury and failed to reliably monitor abdominal lesions. Changes in laboratory parameters have no additional impact on ultrasound follow-up.

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Biopsy

C-085 MRI-guided interventional procedures: Reasons for failure B. Viamonte, L. Melão, A. Almeida, N.P. Leite, R.G. Cunha; Porto/PT (barbaraviamonte@gmail.com)

Learning Objectives: 1. To review the techniques of MR image-guided biopsy and wire localization. 2. To discuss the reasons for failure of MR image-guided interventional procedures.Background: MR guided wire localization and core biopsy are accurate techniques for histological characterization of enhancing breast lesions not seen with mam-mographic or sonographic modalities; however, failure of sampling is subsequently documented in a small percentage of cases. Many limitations of these procedures, which have become evident and published, will be discussed. The possible reasons for failure of MR image-guided tissue sampling procedures are discussed, as well as ways to minimize technical failure.Imaging Findings: Advantages, disadvantages and techniques of MR image-guided wire localization and biopsy that illustrate the points given above are reviewed.Conclusion: Awareness of the causes of procedure failure will improve the success rate of MR sampling techniques.

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Digital Mammography

C-086 Effect of a computer-aided detection system on radiologists’ performance in detection of lesions on mammograms obtained by using a phase contrast digital mammography system T. Tanaka, N. Nitta, S. Ota, K. Tsuchiya, Y. Murakami, S. Kitahara, M. Wakamiya, A. Furukawa, M. Takahashi, K. Murata; Otsu/JP (tanatoyo@gmail.com)

Purpose: To evaluate the effect of a newly developed computer-aided detection (CAD) system on radiologists’ performance in the detection of clustered microcal-cifications and masses on digital mammograms.Methods and Materials: One hundred cases of mammograms (50 abnormals including 19 biopsy proven cancers and 50 normals) were obtained by using a phase contrast mammography (PCM) system. Seven qualified radiologists participated in an observer study based on a receiver operating characteristic (ROC) analysis.Results: The average AUC values obtained from ROC analysis with and without CAD output were 0.927 and 0.897, respectively (p=0.015). The difference between the two AUC values was greater with the less experienced radiologists than with the more experienced ones. The AUC values improved from 0.840 to 0.888 for clustered microcalcifications (p=0.034) and from 0.947 to 0.962 for mass shadows (p=0.025), respectively. Beneficial effects of CAD were confirmed on 12 cases including two biopsy proven cancer cases: the two cases were invasive ductal carcinoma in dense glandular tissue.Conclusion: The CAD system can assist radiologists in detecting both clustered microcalcifications and masses. The application of the CAD system to digital mam-mograms of superior image quality, which are acquired by using a PCM system, is a promising approach for the detection of breast cancer in the early stage.

C-087 Low-dose digital mammography technique by using image processing Y. Fujimura1, H. Nishiyama1, T. Masumoto1, S. Kono1, T. Furukawa1, J. Horiguchi1, K. Ito1, T. Ishida2; 1Hiroshima/JP, 2Higashi-Hiroshima/JP (ysfuji@hiroshima-u.ac.jp)

Purpose: Low-dose digital mammography will be useful for the reduction of patient’s dose. Therefore, we investigated the detectability of simulated lesions with the conditions of various exposure doses and image processing.Methods and Materials: RMI156 phantom images are obtained with the Senogra-phe DS system (GE) with a tube voltage of 28 kV and Mo (anode)/Mo (filter) combi-nation. Different exposure doses ranging from 1.34 to 10.54 mGy are employed to obtain the digital images with different granularities. Those images were processed by the use of Gaussian filter and unsharp masking filters for the evaluation of the effects on image properties based on digital Wiener spectrum (WS), presampled modulation transfer function (MTF). In addition, the observer performance tests for the detectability of microcalcifications and masses are performed.Results: With a 5x5 Gaussian filtering, the WS value decreased to 50% at 2.0 cycles/mm and the detectability score of mass raised up to 32 -80% on 2.62-1.34 mGy (p 0.05). With a 7x7 unsharp masking, the MTF values increased to 226% at 2.0cycles/mm and the detectability score of microcalcification raised up to 5-32% on 5.25-1.34 mGy (p 0.05). For the detection of microcalcifications and masses, the optimal doses were 8.27 mGy, 5.25 mGy, and 9.50 mGy for the original image, the 7x7 unsharp masking, and the Gaussian filtering, respectively. The 7x7 unsharp masking could reduce 37% of exposure dose.Conclusion: We could reduce the exposure dose without a loss of the detect-abilities of microcalcification and mass by using a 7x7 unsharp masking in digital mammogram.

C-088 Effects of reduced dose on observer accuracy with digital mammography A. Roselli, F. Pediconi, S. Padula, V. Dominelli, S. Cagioli, M.L. Luciani, R. Passariello; Rome/IT (anto.roselli@libero.it)

Purpose: To determine the relationship between radiation dose and observer accuracy for detection of malignant masses and microcalcification clusters on digital mammography.Methods and Materials: 200 craniocaudal images with malignant masses and/or clusters of microcalcifications were retrospectively selected from a database of digital mammograms (DR; PlanMed). Each image was originally acquired under automatic exposure conditions, corresponding to an average glandular dose of 1.3 mGy for a standard breast (considered 100% dose level). One level of simulated

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system noise was added to the images to yield a new image set corresponding to simulated dose level of 50% of the original images. The manufacturer’s standard display processing was subsequently applied to all images. Three radiologists experienced in mammography evaluated the images by searching for lesions and marking and assigning confidence levels to suspicious regions. Results were analyzed to determine effects of reduced dose on overall interpretation accuracy, detection of microcalcifications and malignant masses.Results: Dose reduction did not significantly affect the detection of malignant masses; confidence for mass detection was 0.72 and 0.65 at dose levels of 100 and 50%, respectively. Conversely, significantly different confidence scores of 0.91 and 0.64 were assigned for the detection of microcalcifications at dose levels of 100 and 50%, respectively, resulting in an overall statistically significant (p 0.05) difference in overall interpretation accuracy.Conclusion: Reducing the dose level by a factor of two compromised the detection of microcalcifications but had no significant effect on the detection of malignant masses.

C-089 Texture analysis of mammograms: A useful tool in differential diagnosis of breast lesions G.P. Giannakopoulou, S. Golemati, D. Koulocheri, A. Tsakiri, J. Stoitsis, A. Nonni, F. Zagouri, K.S. Nikita, G.C. Zografos; Athens/GR (ggiannakopoulou@gmail.com)

Purpose: To correlate breast tissue histology with image texture features in an attempt to investigate the validity of texture analysis techniques and their potential application in clinical practice.Methods and Materials: 60 patients with non-palpable breast lesions underwent stereotactic directional vacuum-assisted breast biopsies. Regions of interest (ROIs), corresponding to suspect lesions, were defined and outlined by radiologists on the digitized mammograms. Texture analysis was performed using first-order mathemati-cal descriptors estimated from the normalized gray-level histograms of the image ROIs. These included minimal, maximal, median, and mean gray-levels, standard deviation of gray levels, coefficient of variation, and gray-level skewness, kurtosis, entropy, and energy. The fractal dimension was also estimated. Mann-Whitney U test was performed throughout the data analysis.Results: According to the histological results, 13 lesions were ductal carcinoma in situ (DCIS), 16 were invasive carcinomas (IVC), 10 belonged to premalignant breast lesions (lobular neoplasia and atypical ductal hyperplasia) and 21 were be-nign. Mann-Whitney U test (p 0.05) revealed that gray level's maximal (p=0.028), standard deviation (p=0.009), entropy (p=0.03) and energy (p=0.018) were signifi-cantly different between DCIS and IVC. In addition, there was significant difference in gray level energy (p=0.045) and standard deviation (p=0.04) between invasive and premalignant lesions and in entropy (p=0.045) between invasive and benign lesions. Gray-level entropy is a measure of histogram homogeneity, energy corre-lates to pixel distribution in different gray level values, whereas standard deviation characterizes the contrast of the image.Conclusion: Texture analysis provides a quantitative operator-independent as-sessment of breast lesion type and may be helpful in differential diagnosis of breast lesions.

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Magnetic Resonance

C-090 The variety of MR imaging findings on fibroadenoma of the breast: Correlation with pathologic features J. Tominaga, H. Hama, S. Takahashi; Sendai/JP (jrtomi@jf6.so-net.ne.jp)

Learning Objectives: The aim of this exhibit is to show various magnetic reso-nance imaging (MRI) findings of fibroadenomas of the breast and correlate them with pathologic features.Background: Fibroadenomas are common benign tumors of the breast and are often identified at MRI. Fibroadenomas show various MRI findings which reflect a wide spectrum of pathologic characteristics. The radiologist must be familiar with the radiologic-pathologic correlation in various fibroadenomas for correct diagnosis because some of them show similar MRI findings to other tumors that should be resected; for example, phyllodes tumors and mucinous carcinomas. This exhibit provides several examples of fibroadenomas with various MRI findings and dem-onstrates radiologic-pathologic correlation.Imaging Findings: Fibroadenomas of the breast typically manifested as lobulated mass with nonenhancing internal septation on MRI. They demonstrated low to high T2 signal intensity with various degree of enhancement. This variety of MRI findings reflected stromal structure modified by hyalization, fibrosis and myxoid change. Some cases of fibroadenomas showed similar MRI findings (lobulated mass, high T2 signal intensity, various degree of enhancement) to phyllodes tumors and mucinous carcinomas; however fibroadenomas showed more homogeneous T2 signal intensity and enhancement than the others, which reflected their pathologic features. Other cases of fibroadenomas showed overlap MRI findings with breast carcinomas: ill-defined border, peripheral rim enhancement, and washout type signal intensity time course in dynamic MRI, which reflected mastopathic type fibroadenoma, lymphocystic infiltrate adjacent to surrounding fibroglandular tissue, and intralesional abundant vessels on pathologic examination.Conclusion: Fibroadenomas show various MRI findings which reflect those pathologic features.

C-091 MRI of the breast: The breast and so much more R. Bitar, P. Crystal, S. Kulkarni, T.H. Helbich; Toronto, ON/CA (richard.bitar@gmail.com)

Learning Objectives: After reading this educational exhibit, the reader will be able to identify and appropriately work-up the most common non-breast related abnormalities that can be detected when performing breast MRI.Background: MRI of the breast has emerged as an accurate modality for screening and diagnosis of breast carcinoma. As radiologists, we are trained to evaluate all the information available in the field of view, not limiting ourselves just to the target organ being studied. This exhibit will demonstrate the most common non-breast related abnormalities that can be detected when performing breast MRI, providing an approach to identify and manage these lesions.Imaging Findings: The abnormalities will be categorized according to the anatomi-cal compartments in which they are located. These will include: a) chest wall, b) axillary regions, c) the mediastinum, d) the heart/pericardium, e) the lungs and f) the upper abdomen. Examples of the abnormalities will be presented and discussed.Conclusion: Radiologists should be aware of non- breast related abnormalities when reading a MRI of the breast study. Radiologists should perform a comprehensive evaluation of all the anatomy present in the images, and not just the breast tissue, as these examinations will often reveal other significant abnormalities/pathology.

C-092 Mimickers of malignancy and pitfalls in breast MR imaging P. Crystal, K. Bukhanov, Y.-Y. Ong, A. Scaranelo, S. Kulkarni, T.H. Helbich; Toronto, ON/CA (pavel.crystal@uhn.on.ca)

Learning Objectives: To understand the pitfalls encountered in breast magnetic resonance imaging. To identify common and atypical appearance of malignancy. To identify benign lesions which share malignant MR imaging features. To describe an appropriate management of MRI detected abnormalities.Background: MRI of the breast has emerged as an accurate modality for screening and diagnosis of breast. The sensitivity of breast MR for invasive carcinoma is up to 99%, and 50-90% for ductal carcinoma in situ. The relatively low specificity between 50 and 70% is due to overlapping features between benign and malignant pathology. This exhibit will demonstrate benign lesions with MRI features that are suspicious

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for malignancy and provide a basis for management of these lesions.Imaging Findings: Several factors may account for pitfalls in the interpretation of breast MRI. The best predictors of malignancy are irregular or spiculated margins in mass lesions and segmental or linear distribution of enhancement in non-masslike lesions. Atypical appearance of carcinomas include regional and diffuse non-mass-like enhancement, high T2 signal, obscured lesion due to enhancing background parenchyma, and smooth margins. Several benign lesions may share malignant features. These include radial scar, fat necrosis, papilloma, fibrocystic changes, sclerosing adenosis, fibrosis, and normal breast parenchyma.Conclusion: Radiologist should be aware of benign breast pathology that imitates malignancy on MRI. An understanding of the overlapping features between benign and malignant lesions on breast MRI has paramount importance in appropriate manage-ment of breast MRI findings and improving diagnostic accuracy of breast MRI.

C-093 Unusual malignant breast lesions at breast MRI: Radiologic-histopathologic correlation A. Iglesias Castañón, M. Arias Gonzalez, J. Mañas Uxó, M. Herreros Villaravitz, J. León Alonso; Vigo/ES (alfonso.iglesias.castanon@sergas.es)

Learning Objectives: 1. To describe the clinical and MR imaging findings of his-tologically proven unusual malignant breast lesions. 2. To define useful imaging and clinical characteristics, which can aid the correct diagnosis. 3. To understand the MR findings on the basis of pathologic findings.Background: When reading a breast MR, a wide spectrum of unusual malignant lesions can be found. The purpose of this exhibit is to describe the MR appearance of a variety of these unusual biopsy-proven malignant breast lesions, making a correlation with the pathologic findings. Both kinetic and morphologic information in MR imaging were evaluated to recognize the MR characteristics that can con-tribute in making an accurate diagnosis and to avoid misdiagnosis. Data were also correlated with mammographic findings.Imaging Findings: Malignant lesions showed a wide range of findings. Angiosar-coma, metaplastic carcinoma, squamous cell carcinoma, etc. present as irregular masses with marked enhancement. Papillary carcinoma, invasive lobular carcinoma, etc. show moderate enhancement and ill-defined margins. Colloid and medullary carcinoma are typically well-circumscribed masses with minimal enhancement. Invasive tubular cancer presents as a spiculated mass with rim-enhancement.Conclusion: Breast MRI can help in the differential diagnosis of some unusual malignant breast lesions, combining morphological features and contrast uptake curves, and correlating MRI features with clinical history, mammographic and ultrasonographic findings.

C-094 Can breast MRI help evaluate the tumor response to primary radiochemotherapy in patients with large breast cancers? Illustration with clinical cases F. Thibault, A. Tardivon, A. Athanasiou, M.A. Bollet, B. Sigal-Zafrani, R. Salmon, A. Fourquet; Paris/FR (fabienne.thibault@curie.net)

Learning Objectives: To show the key issues in the accurate evaluation of tumor response in breast cancer patients who undergo primary chemotherapy or radio-therapy for large tumors. To illustrate the role of breast MRI in assessing the tumor response to a preoperative regimen of concurrent radiochemotherapy in a series of 60 patients treated at our institution. Patients had conventional and breast MRI assessments before radiochemotherapy and preoperatively. Pathologic data are the reference.Background: Medical neoadjuvant treatments were shown to be effective in large operable breast cancers not amenable to conserving surgery at initial presenta-tion. A new therapeutic option with yet limited evaluation consists of a concomitant combination of chemotherapy with radiotherapy. This option was evaluated in a phase II study. Treatment consisted of four cycles of 5-fluorouracil-vinorelbine with, starting with the second cycle of chemotherapy, radiotherapy to the breast and internal mammary and supra/infra-clavicular lymph nodes. Breast-conserving surgery or mastectomy and axillary lymph node dissection were performed 4-6 weeks after completion of irradiation.Imaging Findings: A panel of concordant and discordant cases based on imaging (MRI based)-pathologic correlations is presented. This includes different morphologic patterns of tumor regression and the relatively higher accuracy of breast MRI com-pared with clinical evaluation, mammography and breast ultrasound. Pitfalls in MRI interpretation that led to over/underestimation of tumor response are also shown.Conclusion: Compared with conventional evaluation, MRI substantially improved the prediction of pathologic tumor response to preoperative radiochemotherapy for large breast cancers. MR imaging was not impaired in this specific clinical setting.

C-095 Evaluation of suspicious nipple discharge by MR mammography based on BI-RADS MRI descriptors Y. Tokuda, K. Kuriyama, A. Nakamoto, H. Sai, K. Yutani, Y. Kunitomi, K. Haneda, M. Kawai, N. Masuda, M. Takeda; Osaka/JP (ytokuda@onh.go.jp)

Purpose: To evaluate the findings of MR mammography for suspicious nipple discharge based on BI-RADS MRI descriptors and establish any correlation with pathologic diagnoses.Methods and Materials: Between August 2003 and September 2006, 51 breasts of 47 patients with suspicious nipple discharge underwent breast MRI using a 1.5-T system. Three radiologists interpreted images independently and arrived at a consensus after discussion. Images were evaluated for a signal of abnormal dis-charge, related abnormal enhancement according to the BI-RADS MRI descriptors, and clustered ring enhancement, and compared with the pathological diagnoses established in 35 breasts.Results: 16 malignant and 21 benign lesions were detected. The most frequent morphologic findings in the benign and malignant lesions were a ‘stippled’ (50%) and ‘segmental distribution’ (59%), respectively. Clustered ring enhancement was found in 60% of the malignant lesions and only 9% of the benign lesions (p=0.02). The most frequent kinetic pattern observed in the malignant lesions was a plateau pattern (40%). A clumped internal architecture (100%), clustered ring enhancement (82%), and a kinetic washout pattern (100%) had the highest positive predictive value for carcinoma. Although the distribution pattern was not useful to differentiate malignant from benign lesions, the combination of segmental distribution and clustered ring enhancement showed a significant association with malignant lesions (p=0.02).Conclusion: The most common breast MRI finding in patients with suspicious nipple discharge was non-mass enhancement. The combination of segmental distribution and clustered ring enhancement showed the highest positive predic-tive value for malignancy. MRI provides clinically useful information in patients with suspicious nipple discharge.

C-096 Diffusion-weighted imaging in breast malignancies: Comparison of different b-value J. Lee, H.-Y. Choi; Seoul/KR (choihy@ewha.ac.kr)

Purpose: The purpose of this study was to evaluate the effect of the different b-value on the diffusion-weighted imaging of preoperative breast MRI in breast cancer.Methods and Materials: A total of 38 patients with 45 breast malignancies underwent breast MRI with diffusion-weighted imaging at our institute between January 2007 and June 2007. We modified the b-values as 300, 500, 700, 1000 second/mm2. Detectability of diffusion-weighted imaging with different b-values was divided into good, fair, and poor.Results: With b-value of 300 second/mm2, detection of breast malignancies were good in 7 of 16 (43.8%) lesions and fair in 9 of 16 (56.2%). With b-value of 500 second/mm2, detection of breast malignancies were good in 4 in 12 (33.3%) lesions; fair in 7 of 12 (58.3%); and poor in 1 of 12 (8.3%). With b-value of 700 second/mm2, detection of breast malignancies were good in 9 of 17 (58.8%) lesions; fair in 6 of 17 (35.3%); and poor in 1 of 17 (5.9%). With b-value of 1000 second/mm2, detection of breast malignancies were good in 32 of 45 (71.1%) lesions and fair in 13 of 45 (28.9%).Conclusion: In conclusion, diffusion-weighted MR imaging with higher b-value show higher detectability. So, diffusion-weighted MRI with higher b-value (700 or 1000 second/mm2) is recommended in the evaluation of breast malignancies.

C-097 Quantitative diffusion weighted imaging in locally advanced breast cancer C. Iacconi, C. Marini, M. Giannelli, A. Cilotti, D. Mazzotta, C. Bartolozzi; Pisa/IT (c.iacconi@med.unipi.it)

Purpose: To measure mean diffusivity (MD) in locally advanced breast cancer.Methods and Materials: 33 women with locally advanced breast cancer were enrolled in an on-going prospective clinical trial. All the patients underwent MR both before the beginning and after the fourth cycle of FEC (5 FU, Epirubicin, Cyclophos-phamyde). All patients were examined using a 1.5 T MR and a dedicated breast coil. The MR acquisition protocol consisted of coronal EPI sequences sensitised to diffusion along 3 orthogonal directions (bvalue 0-1000 sec/mm2), pre and post-contrast 3D coronal T1 sequences. Percentage of neoplasm volume reduction (PVR) was calculated by using the dynamic MR study before and after chemotherapy. Comparison between MD values before and after chemotherapy was performed using Wilcoxon test. Correlation between PVR and pre-chemotherapy MD values was estimated with Spearman-rank correlation testing.

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Results: 15 women (age range: 31-67) completed the study. PVR was 65% in 14/15 patients (responders). In these patients, the mean PVR value was 87 14%. In the responders, we observed an increase of MD values after chemotherapy (1.17 0.31 10-3 mm2/sec) but not statistically significant (p=0.09), while PVR significantly correlated (r=-0.59, p=0.025) with pre-chemotherapy MD values (0.99 0.25 10-3 mm2/sec).Conclusion: This study seems to suggest an increase of MD values after chemo-therapy. Moreover, it is noteworthy that the percentage of neoplasm volume reduc-tion was significantly greater in patients with lower pre-chemotherapy MD values.

C-098 Phase contrast mammography system: Contrast-detail comparison for mammography between phase contrast imaging and flat panel digital images R. Ishii1, A. Yoshida1, M. Ishii2, Y. Higashida3; 1Mihara/JP, 2Kurashiki/JP, 3Fukuoka/JP (ishii@hpc.ac.jp)

Purpose: We evaluated the image quality between the phase contrast imaging for mammography (PCM) and the flat panel detector (FPD) mammography (2000D).Methods and Materials: We measured the physical imaging properties of the PCM and the 2000D. Observer performance experiments were done by using a CD-MAM phantom with the PCM and the 2000D. We exposed a phantom to three parameters, including tube voltage (26, 30, 35 kV), phantom thickness (3, 4, 5, 6 cm), and average glandular dose (1, 2, 3, 4 mGy). Sample images were printed on hard-copies with the optical density variation range within 1.5 0.1. The experi-ment results were evaluated by calculating image quality figures (IQF). Observ-ers included 10 radiological technologists certified as screening mammography technologists in Japan.Results: The IQF increased when the average glandular dose increased when the tube voltage and the phantom thickness were fixed. The IQF decreased when the phantom thickness increased when the tube voltage and the average glandular dose were fixed. However, the IQF did not change when the tube voltage was increased and the average glandular dose and the phantom thickness were fixed. The modula-tion transfer factor of the PCM was less than the 2000D, but the Wiener spectrum at below 1 cycle/mm of the PCM was about the same as the 2000D.Conclusion: Observer performance did not show a significant difference between the PCM and the 2000D. However the resolution of the PCM was less than the 2000D and the noise properties were about the same in the low frequency region.

C-099 Advantages of contrast enhanced MRI in the estimation of breast cancer extent before breast-preserving surgery E.A. Yukhno, G. Trufanov, S.V. Serebryakova, V.A. Fokin; St. Petersburg/RU (l55@yandex.ru)

Purpose: To compare the diagnostic value of MRI with contrast enhancement ac-cording to tumor with conventional imaging methods (sonography, mammography) before breast-preserving surgery.Methods and Materials: 82 female patients (mean age 54 3 years old) with breast malignancy underwent contrast-enhanced MRI, breast sonography and mammography before breast-preserving surgery. The largest diameter of mass was evaluated on the sonograms, mammograms and on the MR images in three planes. The results were compared with pathological findings.Results: Conventional methods detected precise size of tumor only in 57 of 82 (70%) patients; the underestimation occurred in 21 (26%) cases and overestimation in 4 (4%) cases. MRI allowed precise detection of tumor size in 75 patients (91%); underestimation and overestimation was registered in 4 (5%) cases and 3 (4%) cases, respectively. MRI with contrast enhancement demonstrated best correlation with pathological findings in comparison with traditional imaging (91 vs. 70%). Both MRI and conventional imaging methods assessed tumor size with equal accuracy in 68% of patients (56 of 92).Conclusion: MRI allows more accurate estimation of tumor extent than breast US and mammography in patients selected for breast-conserving surgery in every fourth case. Besides, this method provides additional data and improves evaluation of tumor size in cases when conventional imaging methods over- or underestimate extent of infiltration (with difference more than 10 mm in comparison with pathological findings).

C-100 Analysis of breast MR limits in the management of patients treated with neo-adjuvant chemotherapy A. Cilotti, C. Marini, D. Mazzotta, C. Iacconi, C. Giaconi, V. Battaglia, R. Scandiffio, C. Bartolozzi; Pisa/IT

Purpose: To evaluate the usefulness of contrast enhanced MR in measuring the diameter of residual malignancy in patients treated with neoadjuvant chemo-therapy.Methods and Materials: MR studies of 27 patients (28 lesions) with locally ad-vanced breast carcinoma were retrospectively revaluated. Standard high field (1.5 T) MR study was performed in all cases before and after the primary chemotherapy. MR measurements were compared to histological results. The analysis of MR images had been optimized in order to identify residual disease in treated breast.Results: MR showed a sensibility of 84%, a specificity of 67%, a PPV of 95% and a NPV of 33%. The correlation with pathology is an r value of 0.15.Conclusion: Although MR is considered the best technique in evaluating the usefulness of neoadjuvant chemotherapy, the main reasons of its limits are: 1. MR is considered the gold standard before surgery, but the absolute gold standard is represented by histological measurement, not available at the beginning of the treatment; 2. difficulties in comparing MR lesion extension to histological dimen-sions; 3. difficulties in differential diagnosis at MR between residual cancer and associated high grade proliferative disorders; and 4. difficulties in comparing MR functional parameters and lesion angiogenesis at histology. Next desirable devel-opments are: 1. collaboration between the radiologist and the pathologist in order to define comparable criteria between the histological measurement and the MR ones; and 2. to find out a relation between MR functional parameters and immuno-histochemical data of angiogenesis.

C-101 Contrast enhanced MR mammography (CE-MRM): Comparison of the blood pool agent B22956/1 and Gd-DTPA for detection and differentiation of benign and malignant breast lesions V. Dominelli, F. Pediconi, C. Catalano, A. Roselli, S. Cagioli, M.L. Luciani, R. Passariello; Rome/IT (valeria.dominelli@yahoo.it)

Purpose: To compare the diagnostic performance of the blood pool agent B22956/1 with that of gadopentetate dimeglumine (Gd-DTPA) for differentiation of benign and malignant breast lesions based on microvascular permeability.Methods and Materials: Twelve patients with suspected breast lesions at X-ray mammography and ultrasound (BIRADS 4 or 5) underwent two identical CE-MRM examinations with Gd-DTPA and B22956/1 separated by 48-72h. Dynamic 3D Flash T1-weighted GRE images were acquired before and after injection of either Gd-DTPA or B22956/1 (0.1 mmol/kg). All lesions were surgically excised within 1-15 days (mean, 9 days). Quantitative and qualitative enhancement data were obtained and analysed according to the shape of the tumor enhancement curves. The endothelial transfer coefficient was calculated for each tumor and each contrast agent using a bi-directional kinetic model. All quantitative MRI data were correlated with histopathology.Results: Two patients had no lesions at CE-MRM with either contrast agent. Histo-pathology determined 3 benign (1 sclerosis adenosis, 1 fibroadenoma, 1 papilloma) and 7 malignant (1 atypical ductal hyperplasia, 4 invasive ductal carcinomas, 2 invasive lobular carcinomas) lesions in the remaining 10 patients. High sensitivity was obtained with both agents. The greater microvascular permeability of B22956/1 permitted differentiation of benign and malignant lesions. The endothelial transfer coefficient for the albumin-bound part of B22956/1 was lower in benign lesions than in malignant tumors. No correlation between tumor histopathology and apparent microvascular permeability to Gd-DTPA was found.Conclusion: B22956/1 permits improved characterization of lesions. This could impact clinical management if confirmed in a larger cohort of patients.

C-102 Evaluation of neoadjuvant chemotherapeutic response of breast cancer by MRI: Accuracy of MRI in predicting pathological complete response N. Gomi, Y. Yamamoto, K. Matsueda, Y. Fujiwara, H. Tanaka, A. Kohno, Y. Miyagi, T. Iwase, Y. Itoh, F. Akiyama; Tokyo/JP (naoya.gomi@jfcr.or.jp)

Purpose: The importance of evaluation of pathological complete response (pCR) has been confirmed by the fact that there is a close correlation between pCR to neoadjuvant chemotherapy (NAC) and prognosis of breast cancer. The objective of our study was to determine the accuracy of MRI in predicting pCR after NAC.Methods and Materials: 145 women with stage IIB-III solid breast cancer under-went dynamic contrast-enhanced T1WI of the entire breast, before and after pre-

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operative NAC. On imaging, complete response (iCR) was defined as no enhanced tumor on all serial images. All patients underwent radical or conservative surgery, and imaging findings were compared with pathologic findings.Results: 21 of 145 patients had iCR after NAC. 11 of the 21 iCR patients (52%) were identified correctly with pCR (no histological evidence of invasive tumor cells). Yet in 10 of 21 iCR patients (48%), MRI underestimated the residual tumor. In 6 of the 10 patients who were underestimated on MRI, resected specimens showed marked response to chemotherapy and only a small amount of residual tumor was detected. In four of 10 patients, resected specimens showed mild response to chemotherapy and a considerable amount of residual tumor was detected.Conclusion: MRI seems to reflect pathological conditions after NAC effectively, and appears to provide good correlation with pCR. 52% of the patients who were evalu-ated as iCR were pCR. At the same time, there are cases where no tumor is detected on MRI, but a considerable amount of residual tumor is found pathologically.

C-103 The role of MRI in the diagnosis of Paget’s disease of the breast O. Golan, F. Sperber, A. Gat; Tel Aviv/IL (oritgolan@gmail.com)

Purpose: The prevalence of an associated cancer in Paget’s disease of the breast ranges from 67 to 100%. Treatment of Paget’s disease is either mastectomy or breast conserving surgery involving resection of the nipple areola complex, depending on the extension of underlying disease. Mammography is of limited value in man-agement of Paget’s disease for women without palpable mass; the true extent of the disease is underestimated in 43% of cases. To evaluate MRI ability to detect underlying cancer in patients with Paget’s disease of the breast without palpable mass compared to mammography.Methods and Materials: Eleven cases of nipple biopsy proven Paget’s disease of the nipple presenting with non palpable mass underwent mammography ultra-sound and MRI to evaluate underlying breast cancer. The patients’ imaging studies were retrospectively reviewed. Imaging findings were correlated to histopathologic results.Results: Histopathology showed associated breast cancer (ductal carcinoma in situ or invasive ductal carcinoma) in ten out of eleven patients (91%). Mammography showed no underlying diseased in seven cases (64%) and DCIS in four cases (36%). The sensitivity and specificity of mammography was 40 and 100%, respectively. MRI showed underlying disease in all ten cases (invasive disease 27%, DCIS 46% both invasive disease and DCIS 18%). MRI sensitivity and specificity were both 100%. MRI results affected the surgical treatment decision in 91% of cases.Conclusion: Mammography is limited in the evaluation of underlying cancer in patients with Paget’s disease. MRI should be suggested in the pretreatment workup of these patients to guide further surgical planning.

C-104 Use of T2-weighted images in computer-aided diagnosis for breast MRI W. van Aalst1, T. Twellmann1, H. Buurman2, F. Gerritsen2, B. ter Haar Romeny1; 1Eindhoven/NL, 2Best/NL

Purpose: To evaluate the use of lesion features derived from T2-weighted images in computer-aided classification of benign and malignant masses in dynamic contrast-enhanced (DCE) magnetic resonance imaging studies of the breast.Methods and Materials: Fat-suppressed DCE-T1-weighted and non-fat-sup-pressed T2-weighted images of 50 patients containing 64 masses (28 benign and 36 malignant) were acquired. All masses were segmented in the DCE-T1-weighted images using a semi-automatic method. Twenty-two morphological and kinetic DCE-T1-weighted features proposed in literature were computed for each mass. Additionally, 14 quantitative T2-weighted features were defined and evaluated. These features are mainly based on the intensity characteristics within the lesion or within the enclosing shell of normal tissue. The intensity values were normal-ized with respect to the mean intensity of different reference regions to account for the qualitative and inhomogeneous nature of MR images. Feature selection was performed to determine the best set consisting of not more than five DCE-T1-weighted features and the best set combining not more than a total of five DCE-T1-weighted and T2-weighted features. Subsequently, a linear classification function was estimated by Fisher discriminant analysis.Results: In a leave-one-out evaluation, including T2-weighted features improved the classification performance from an area-under-the-ROC-curve of 0.94 to 0.99, yet a test for statistical significance failed with p=0.064. The selected T2-weighted features reflect the existence of bright structures in the surrounding tissue (caused by e.g. edema) and dark areas within the lesion.Conclusion: The obtained results encourage the use of quantitative information from T2-weighted images in CAD for breast MRI.

C-105 The influence of tumor histology, tumor size, tumor grade and receptor profile on the pharmacokinetic parameters of invasive carcinomas of the breast R.M. Mann, H. Huisman, J. Veltman, C. Boetes; Nijmegen/NL (r.mann@rad.umcn.nl)

Purpose: To determine the influence of tumor histology, tumor size, tumor grade, and hormonal receptor profile on the expression of kinetic contrast enhancement parameters in patients with breast cancer.Methods and Materials: The MRI scans of all patients with invasive cancer (IDC or ILC) of the breast, operated between 2003 and 2006, who underwent pre-operative dual time resolution MRI were collected. Presence of wash-out was determined by visual assessment. An ROI was drawn around the whole tumor. For all tumors the median and 75th percentile, representing a whole tumor and a hotspot approach, of: wash-out, transfer constant (Ktrans), and extracellular volume (ve), derived by pharmacokinetic modelling of dynamic sequences with a temporal resolution of 4s, using a per patient callibrated Tofts model, were calculated. Tumor histology, size, grade, and hormonal receptor profiles were collected from the pathology reports.Results: The dataset comprised 98 IDC and 32 ILC carcinomas. Wash-out was more common in IDC (83/98) than in ILC (16/32) (p 0.01). Extra cellular volume (ve) was not significantly different between IDC and ILC. Ktrans was lower in ILC than in IDC, especially when using a hotspot technique 1.20/min vs 1.84/min (p=0.03). Tumor size and tumor grade are not reflected in the dynamic parameters nor is the hormonal receptor profile.Conclusion: The lower Ktrans in ILC reflects a pathophysiological difference in permeability surface area compared to IDC. Consequently, enhancement is slower in ILC than in IDC. The decrease in wash-out pattern is a similar but indirect ex-pression of that difference.

C-106 Diffusion-weighted imaging in breast cancer: ADC value and tumor grading correlation P. Belli, M. Costantini, C. Ierardi, R. Lombardi, E. Bufi, L. Bonomo; Rome/IT (mcostantini@rm.unicatt.it)

Purpose: To evaluate the role of diffusion-weighted imaging (DWI) in breast cancer and to correlate the apparent diffusion coefficient (ADC) with tumor grading in malignant breast lesions.Methods and Materials: From January 2005 to December 2006, all patients with malignant breast lesion who underwent breast MRI in our department were stud-ied with the same MRI protocol, including DWI sequence. For each breast lesion ADC value was calculated. ADC values were compared to pathological results including tumor grade.Results: 68 female Patients (mean age: 51.4 years, range: 25-84 years) for a total of 95 breast lesions were included in our study. Mean diameter of lesions was 27.0 mm (range: 4-90 mm). Mean ADC value of lesions was 0.91 x 10-3 mm2/s. Pathology results revealed 14 ductal carcinomas in situ (mean ADC value: 0.96 x 10-3 mm2/s), 10 invasive lobular carcinomas (mean ADC value: 0.82 x 10-3 mm2/s), 70 invasive ductal carcinomas (mean ADC value: 0.94 x 10-3 mm2/s) and 1 tubular carcinoma (ADC value: 0.81 x 10-3 mm2/s). There were 12 G1, 37 G2 and 46 G3 carcinomas. Mean ADC value was 1.28 x 10-3 mm2/s for G1 carcinomas, 1.01 x 10-3 mm2/s for G2 carcinomas and 0.87 x 10-3 mm2/s for G3 carcinomas.Conclusion: In our preliminary study, diffusion-weighted imaging and ADC mea-surements showed a potential role in the breast cancer diagnosis and characteriza-tion. ADC value was low in all cases and seems to correlate with tumor grading: ADC value decrease increasing tumor grade.

C-107 ADC value changes in diffusion MRI after neoadjuvant chemotherapy in breast cancer P. Belli, M. Costantini, C. Ierardi, R. Lombardi, E. Bufi, L. Bonomo; Rome/IT (pbelli@rm.unicatt.it)

Purpose: To evaluate the role of diffusion-weighted imaging (DWI) and the appar-ent diffusion coefficient (ADC) as suitable biomarker of response to neoadjuvant chemotherapy (NAC) in locally advanced breast cancer.Methods and Materials: From June 2006 to July 2007, we enrolled 24 female patients with locally advanced breast cancer who underwent MRI in our depart-ment, including DWI sequence, before and after 3 or 6 cycles of NAC (respectively 11 and 14 women). The ADC value changes were compared to the response to treatment and to histological type.Results: Mean age of patients was 46.5 years. Mean size of cancer at diagnosis was 56 mm. A definitive pathological diagnosis obtained after biopsy revealed 13 CDI, 5 CLI, 4 poor differentiated carcinomas, 1 papillary carcinoma and 1 muci-

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nous tumor. Detection rate of DWI was 100%. After NAC, ADC value increase was observed in 22/24 (91%) patients. In only 2 cases ADC value did not show modifications; there were two minor response cases. 40% and 43.4% ADC value increase was noted respectively in the major and minor response. In the 3 no re-sponse patients ADC increase was 31.3%. ADC value showed a greater increase in patients who underwent 6 cycles of NAC than that who received 3 cycles of treatment (50.2% vs 37.3%).Conclusion: ADC value in breast cancer tissue significantly increases after neoadjuvant chemotherapy. Our preliminary results did not show a good correla-tion between type of response and ADC changes. More studies are necessary to understand if ADC change was a suitable indicator of response to treatment.

C-108 Comparison of the diagnostic value of visual assessment of parametric images calculated by a computer assisted diagnosis system with region of interest (ROI) measurement in MR-mammography (MRM) P.A.T. Baltzer, D.M. Renz, S. Beger, C. Freiberg, J. Böttcher, M. Gajda, O. Camara, W.A. Kaiser; Jena/DE (pascal.baltzer@med.uni-jena.de)

Purpose: Available CAD systems for MRM analyze dynamic data and display the results as colour-coded parametric images, offering the possibility of fast visual estimation of contrast enhancement. This investigation was performed to compare the CAD method with standard ROI measurements.Methods and Materials: 329 patients undergoing operation of breast lesions after MR-Mammography (1.5 T, 0.1 mmol/kg bw Gd-DTPA) were analyzed using a CAD-system (CADSciences, USA). CADSciences processes dynamic data using a pharmacokinetic algorithm and displays the results as a colour-coded overlay with red (suspicious), green (intermediate) and blue (benign) voxels. The most suspect curve type (continuous increase: 10%; plateau: 10%; washout: 10% signal decrease) was assessed before the use of CAD by two blinded observers using the ROI method. Washout and plateau curves were counted suspicious of malignancy. Both observers also visually assessed the parametric images, rating lesions benign or malignant. Not threshold reaching lesions ( 33%) were counted negative. Kappa statistics and diagnostic parameters were calculated for ROI and CAD results.Results: Pathology revealed 469 lesions (279 malignant, 190 benign). 276 malig-nant (98.9%) and 174 (91.6%) benign lesions were colour-coded by CAD. Using the ROI method, a sensitivity of 75.3% (210/279) and a specificity of 76.3% (145/190) was revealed. Visual assessment of parametric images led to sensitivity and speci-ficity values of 74.9% (209/279) and 77.9% (148/190). Kappa was calculated with 0.74, accuracy amounted to 75.7% (ROI) and 76.1% (CAD).Conclusion: Our results show a comparable diagnostic accuracy of both analyzed methods to estimate dynamic MRM data.

C-109 Diagnostic role of CAD-analysis of axillary lymph nodes on pretherapeutic dynamic breast MRI on breast cancer patients A. Malich, A. Kott, A. Beier, R. Gorna, J. Feger, S. Schnohr, H.-F. Holzwarth; Nordhausen/DE (ansgar.malich@shk-ndh.de)

Purpose: When applying CAD for analysis of axillary lymph node kinetics in breast-MRI, lymph node enhancement kinetics, including peak contrast uptake can be obtained. The study aimed to determine if enhancement kinetics can differentiate histologically verified benign and malignant nodes.Methods and Materials: 117 consecutively selected pretherapeutic breast MRI examinations of breast cancer cases performed at our institution exclusively were analyzed by CAD (Confirma, USA) on patients finally undergoing a surgical therapy including a lymphadenectomy. Enhancement kinetics of axillary nodes were ana-lyzed and compared to histopathological outcome of the nodal status.Results: 80/117 cases remained without metastatic axillary nodes, and 37/117 showed a metastasis. 26/80 non metastatic cases remained without a visible lymph node in MRI. 54/80 nodes were visible, 14/54 visible benign nodes remained without any contrast uptake regarding CAD-analysis. 37/37 metastatic nodes were visible in MRI, 36/37 cases showed an enhancement according to CAD-analysis. Peak contrast uptake was significantly higher and initial rapid contrast uptake was significantly stronger in metastatic nodes vs. benign nodes. Using ROC-based optimal cut off value of peak uptake (240%) sensitivity, specificity, PPV and NPV of the diagnosis of lymph node metastases were: 89.2%; 88.8%, 78.6% and 94.7%, respectively. Cardiac artifacts limited the analysis of enhancement characteristics in eight cases only.Conclusion: Metastatic axillary lymph nodes differ significantly from non meta-static nodes regarding contrast uptake which can be detected automatically and objectively using CAD. Using this option, a reliable and accurate diagnosis of even subtle axillary metastases on breast cancer cases seems to be possible.

C-110 Contrast appearance of breast cancer after chemotherapy: A radiologic and histopathologic correlation in dynamic magnetic resonance mammography (MRM) A.B. Herzog, P.A.T. Baltzer, D.M. Renz, M. Dietzel, M. Gajda, O. Camara, W.A. Kaiser; Jena/DE

Purpose: To evaluate the MRI contrast medium appearance of invasive breast cancer after neoadjuvant chemotherapy (NC) in correlation with histopathological results.Methods and Materials: In 2005 and 2006, 40 patients with 41 histologically verified invasive breast cancers underwent dynamic MRM before and after neo-adjuvant chemotherapy at our institution. The MRM were obtained on a 1.5 T imager according to a standard protocol and study design (2D-FFE sequences, 0.1 mmol/kgbw Gd-DTPA, T2-TSE). There were 37 ductal, 1 lobular, 1 ductal-lobular and 2 medullary carcinomas.Results: Contrast appearance: maintained cancer corner (suspicious signal intensity course as plateau- and washout phenomenon) (18/43.9%), cut cancer corner (continuous enhancement) (14/34.1%), no contrast enhancement (9/21.9%), sensitivity 86.2%, specificity 83.3%, PPV 92.6%. Morphologic chances in contrast enhancement: cancer resistance sign (no chance or minimal response) (17/41.5%), shrinking star (15/36.6%), no contrast enhancement (9/21.9%), sensitivity 85.7%, specificity 84.6%, PPV 92.3%. Carcinomas with histological signs of regression (Chevalier 1 or 2) after neoadjuvant chemotherapy (13/31.7%) had a higher amount of cases with changed contrast kinetic parameters compared to those with poor response to chemotherapy (Chevalier 3 or 4) (28/68.3%).Conclusion: Histological regression of breast cancer is possible to be reflected by dynamic MRM. Dynamic MRM can be an option to accompany neoadjuvant chemotherapy to show the vitality of an invasive breast cancer. Resistant enhance-ments, especially like maintained suspicious signal intensity course, should be suspicious for vital tumour parts.

C-111 Dynamic CE-MRI of the breast at 3.0 T: A prospective comparative study between spectral fat suppression and image subtraction E. Eracleous1, C. Economides1, S. Kokkis1, I. Seimenis1, K. Kiale2, C. Tsompanlioti2, O. Benekos2, N. Kelekis2; 1Nicosia/CY, 2Athens/GR (kelnik@med.uoa.gr)

Purpose: To compare spectral fat saturation with image subtraction for fat signal elimination in dynamic CE-MRI of the breast at 3.0 T through a prospective intra-individual study.Methods and Materials: Ten women referred for preoperative staging of biopsy proven breast cancer underwent bilateral CE-MRI at 3.0 T and at two imaging sessions 24 hours apart. The two pulse sequences compared were a 3D, RF-spoiled gradi-ent echo sequence (TR=9.5 ms, TE=6.9 ms, flip-angle=20o) and a 3D, RF-spoiled, segmented (186 shots) gradient echo sequence spectral fat suppression (TR=7.1 ms, TE=4.6 ms, flip-angle=10o). Five dynamics (one before and four immediately after a bolus contrast injection) and 50 contiguous sections (2.5 mm thickness) per dynamic were acquired with each sequence using sensitivity encoding. Temporal resolution (1 min 45 sec) and in-plane spatial resolution (0.5 mmx0.5 mm) were identical in both sequences. Off-line image interpretation was performed by two radiologists on subtracted and original images. Image quality, number and enhancement rates of lesions, as well as Gottingen scoring system groups, were compared.Results: Identical number of lesions was identified with both techniques, but overall image quality scores were slightly higher for the plain gradient pulse sequence. Image subtraction appears to be the most robust technique, since fat suppression is not always homogeneous, whilst normal fibroglandular tissue enhancement with the segmented sequence seems to obscure margin definition of lesions.Conclusion: A plain gradient echo pulse sequence and a dynamic subtraction technique seems to lead to higher diagnostic confidence in MR mammography at 3.0 T compared to a segmented gradient echo sequence with spectrally selective fat saturation.

C-112 Malignant and benign inflammation in MR-mammography: Can MRI distinguish inflammatory breast carcinoma from acute mastitis? D.M. Renz, P.A.T. Baltzer, J. Böttcher, F. Thaher, T. Vag, M. Gajda, O. Camara, W.A. Kaiser; Jena/DE (diane.renz@med.uni-jena.de)

Purpose: MR imaging has proven benefit in precisely differentiating between malignant and benign lesions, such as fibroadenomas. However, the value of MRI in distinguishing inflammatory breast carcinoma from acute mastitis is still controver-

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sial, based on limited data. The purpose of this study was to evaluate the potential of MRI to discriminate between malignant and benign inflammations.Methods and Materials: MR examinations (1.5 T; 0.1 mmol Gd-DPTA/kg bw) of 48 patients with inflammatory carcinoma were compared with a collective of 42 subjects with acute mastitis. All patients presented a rapid onset of clinical inflam-matory symptoms. Multiple dynamic and morphological MR imaging parameters were evaluated, using T1- and T2-weighted sequences.Results: For the following parameters, no significant differences of prevalences could be revealed between the two inflammation entities (p 0.05): morphology of focal masses, morphological pattern of non-mass like enhancement, breast enlargement, diffuse skin thickening, pathological nipple configuration, prominent vessels, cutaneous/subcutaneous, perimamillar and diffuse oedema. However, inflammatory carcinomas showed more frequently an initial signal increase 100% and a postinitial wash-out sign in comparison with mastitis cases (p 0.001). The following morphological criteria were also found more frequently in inflammatory carcinomas (p 0.01): infiltration of the pectoralis muscle (54.2% inflammatory carcinoma/ 16.7% mastitis), perifocal oedema (66.7%/33.3%), prepectoral oedema (72.9%/31.0%), intramuscular pectoral oedema (41.7%/7.1%) and focal masses 1 cm (75.0%/31.0%).

Conclusion: Focussing on a limited selection of imaging parameters might not be sufficient for the precise and timely differential diagnosis between malignant and benign inflammations in MRI. However, considering multiple dynamic and morphological criteria seems to be promising.

C-113 Oedema in MR-mammography: Analysis of different localisations and their correlation with histology in invasive breast carcinomas D.M. Renz, P.A.T. Baltzer, M. Herold, A.B. Herzog, M. Dietzel, M. Gajda, O. Camara, W.A. Kaiser; Jena/DE (diane.renz@med.uni-jena.de)

Purpose: Although invasive breast carcinomas frequently present oedema in MR-mammography, the different localisations of this imaging feature have not been analysed in detail. This study was performed to evaluate the prevalences of different oedema localisations and to correlate them with histopathological findings.Methods and Materials: MR examinations (1.5 T; 0.1 mmol Gd-DPTA/kg bw) of 81 patients with unilateral invasive breast carcinoma were analysed. None of the subjects had breast surgery or radiation therapy prior to MRI. 77.8% of all maligno-mas were histopathologically characterised as invasive ductal, 17.3% as invasive lobular and 4.9% as invasive medullary. 32.1% of all tumours were classified as G2 (moderately differentiated) and 67.9% as G3 (poorly differentiated).Results: In 70.4% of all carcinomas, unilateral asymmetric oedema was detected by the analysis of turbo-spin-echo T2-weighted sequences in the following localisa-tions: 6.2% cutaneous/subcutaneous, 12.3% perimamillar, 25.9% diffuse, 69.1% perifocal, 38.3% prepectoral, 7.4% intramuscular pectoral. 42.3% of all G2 tumours, whereas, 83.3% of all G3 carcinomas presented asymmetric oedema (p 0.05). Thus, diffuse, perifocal, prepectoral and intramuscular pectoral oedema significantly occurred more often in G3 malignomas. In carcinomas with histopathologically proven lymphangiosis, all evaluated oedema types were detected more frequently (p 0.05). No significant differences of oedema prevalences could be revealed for different histopathological cancer types (invasive ductal vs. lobular).Conclusion: Breast oedema seems to be a promising morphological imaging fea-ture in the precise diagnosis of invasive carcinomas and can clearly be detected by using T2-images. Especially aggressive malignomas with histopathologically proven high grade and lymphangiosis seem to present an oedematous involvement.

C-114 Diagnosis of ductal carcinoma in situ using contrast-enhanced magnetic resonance mammography T. Vag, P.A.T. Baltzer, D.M. Renz, S.O.R. Pfleiderer, M. Gajda, O. Camara, W.A. Kaiser; Jena/DE (Tibor.Vag@med.uni-jena.de)

Purpose: To correlate histopathologically verified subtypes of ductal carcinoma in situ (DCIS) lesions with mammographic and magnetic resonance (MR) imaging outcomes.Methods and Materials: Twenty-three patients with twenty-three histopathologically verified pure DCIS lesions (no invasion or microinvasion) after excisional biopsy and advanced diagnostic procedures prior to surgery including mammography and MR mammography (MRM) were identified. Patient age ranged from 36 to 79 years with a mean of 60, lesion size ranged from 1 mm to 23 mm size with a mean of 11 mm. Histopathological outcome was graded according to the Holland classifica-tion, which distinguishes between well-, intermediately-, and poorly differentiated DCIS subtypes (G1-G3).Results: RM enabled identification of DCIS in 20 of 23 patients with diagnosis of

pure DCIS in 16 patients (four G1, eight G2 and four G3 subtypes) and diagnosis of DCIS with invasive cancer in 4 patients, giving an overall sensitivity of 87%. Three DCIS lesions (one G1 and two G2 subtypes) of 3 mm diameter or smaller were not detected by MRM. In mammography, 13 of the 23 patients with histopathologically verified pure DCIS revealed suspicious microcalcifications (including the three lesions not detected by MRM) and 1 of 23 patients showed a suspicious focus, demonstrating an overall sensitivity of 60.9%. The remaining 9 mammograms showed no signs of malignancy. All nine mammographically occult DCIS lesions were identified in MRM.Conclusion: MRM can depict mammographically visible and occult DCIS lesions. Some very small foci of DCIS detected at mammography and histopathology, however, may be occult at MRM.

C-115 Diffusion weighted imaging for the assessment of lymph node status in patients with invasive breast carcinomas D.M. Renz, P.A.T. Baltzer, J. Böttcher, D. Grässel, M. Dietzel, A. Preisser, J.R. Reichenbach, W.A. Kaiser; Jena/DE (diane.renz@med.uni-jena.de)

Purpose: The value of diffusion weighted imaging (DWI) in the diagnosis of invasive breast carcinoma has already been proven by several investigations. This study was performed to investigate if DWI can also assess the axillary lymph node status in patients with breast cancer.Methods and Materials: MR examinations (1.5 T; 0.1 mmol Gd-DPTA/kg bw) of 42 patients with invasive breast carcinoma were analysed. DWI was acquired by axial echo-planar images with b-values of 0, 750 and 1000 s/mm2. Apparent diffusion coefficient (ADC) maps were reconstructed for all subjects. An average ADC value of each lymph node was measured by placing three regions of interest in their margin. 26 of 42 patients had sentinel lymph node excisional biopsy after MRI; the remaining 16 subjects underwent axillary node dissection.Results: In 21 patients, histology revealed metastatic lymph nodes with a mean ADC value of 0.89 0.18x10-3 mm2/s (ranges from 0.48x10-3 mm2/s to 1.14x10-3 mm2/s). The mean ADC value of 21 subjects with negative node status was significantly higher (p 0.05): 1.15 0.24x10-3 mm2/s (ranges from 0.72x10-3 mm2/s to 1.50x10-

3 mm2/s). A receiver operating characteristic (ROC) curve was used to determine the cutoff ADC for distinguishing malignant from benign nodes. When an ADC of 1.01x10-3 mm2/s was used as threshold, the sensitivity, specificity and accuracy were 75.0%, 72.2% and 78.6%, respectively.Conclusion: Lymph nodes can clearly be detected by diffusion weighted images. DWI with ADC mapping might be a promising additional tool for determining the node status of patients with invasive breast carcinoma.

C-116 The accuracy of diffusion weighted imating (DWI) for the diagnosis of residual breast cancer after neoadjuvant chemotherapy R. Woodhams, S. Kakita, H. Hata, M. Ozaki, H. Nishimaki, S. Kan, K. Hayakawa; Sagamihara/JP (reikow@hotmail.co.jp)

Purpose: This study evaluates the usefulness of diffusion weighted imaging (DWI) for detecting the residual tumor after neoadjuvant chemotherapy.Methods and Materials: Thirty-four patients who had breast MRI including DWI before the first cycle and after each cycle of chemotherapy was analyzed. MRI exams were performed with 1.5 T GE MRI scanner. For DWI, b value was 0 and 1500s/mm2. The presence of high intensity lesion in the tumor lesion on DWI was determined as residual tumor by visual inspection. ADC value was not measured as the measurement would be inaccurate when the tumor gets small after chemo-therapy. Contrast-enhanced T1 weighted imagings (CE-T1WI) were also compared with DWI. All patients had operation and obtained histologic diagnosis.Results: Four patients were diagnosed as histological complete response (CR), whereas one of them showed high intensity mass on DWI and enhanced mass lesion on CE-T1WI, which is a false positive case. Two patients of pathological CR were diagnosed accurately on DWI; in contrast, CE-T1WI showed delayed enhancement. Residual intraductal components of two patients were not detected on DWI, which are false negative cases. These cases showed delayed enhancement on CE-T1WI. Sensitivity and specificity of DWI was 93% and 75%, respectively.Conclusion: DWI can diagnose the presence of residual tumor with reasonable accuracy, which will be comparable to CE-MRI, with the benefit of no contrast medium and short scan time. There are some problems of DWI, limitation of spatial resolution to diagnose the small or sparse intraductal lesions, and visual diagnostic approach, which is less objective.

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C-117 Analyzing “texture” of lesion enhancement kinetics in dynamic contrast enhanced MRI for breast cancer diagnosis A. Karahaliou1, K. Vassiou2, D. Kanavou2, S. Skiadopoulos1, A. Yiakoumelos1, L. Costaridou1; 1Patras/GR, 2Larissa/GR (avassiou@med.uth.gr)

Purpose: Given that contrast uptake heterogeneity of breast lesions in dynamic contrast-enhanced MRI is diagnostically important, this study investigates whether texture features extracted from enhancement kinetics feature maps can be used for breast cancer diagnosis.Methods and Materials: 55 women with 57 histologically verified breast lesions (27 benign, 30 malignant) were examined. Coronal 3D T1-weighted spoiled gradient echo sequence was acquired before and five times after intravenous administration of gadopenate dimeglumine (0.2 mmol/kg). For a selected slice, most representative of the lesion, a bilinear model was fitted pixel-wise to corresponding time series and fitted parameters were used to create 3 kinetic feature maps (wash out, time to peak enhancement and peak enhancement). Maps were converted to a single HSV color-coded image, subsequently used for delineating lesion uptake boundary. 32 first and second order statistics texture features were extracted from correspond-ing lesion uptake regions of each map. The most discriminating subset of features (combination of 2-5 features) was selected per map, via exhaustive search, using probabilistic neural network and leave-one-out training-testing methodology. Final classification was obtained by combining classification outputs of the selected fea-ture subsets, with majority voting. The area under Receiver Operating Characteristic curve (AUC) was employed to evaluate classification performance.Results: Among individual map classifications, the wash out map provided the high-est AUC=0.90 0.04. The combined scheme outperformed statistically significantly individual map classifications (z-score test, p 0.05), achieving AUC=0.98 0.01.Conclusion: Texture analysis can efficiently quantify heterogeneity of lesion contrast uptake and may contribute to computer assisted diagnosis of breast cancer in MRI.

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Ultrasound

C-118 BI-RADS 3, 4 and 5 lesions on US: Five categories and their diagnostic efficacy and pitfalls in interpretation M. Kim, S. Chong, Y. Kim, S. Park, E. Park; Seoul/KR (j3mn@chol.com)

Learning Objectives: 1. To classify BI-RADS 3, 4 and 5 lesions on US into five categories according to imaging-pathologic correlation. 2. To describe and illustrate their US and pathologic features. 3. To discuss the diagnostic efficacy and the pitfalls in interpretation.Background: BI-RADS lexicon for breast sonography had been applied to stan-dardize the characterization of sonographic lesions. Many studies have assessed the utility of sonographic features in distinguishing benign from malignant lesions. Several study found that descriptors from the sonographic BI-RADS lexicon can be useful in differentiating benign from malignant solid masses. However, there has been discrepancy among the final clinical outcome of BI-RADS category 3, 4 and 5 for diagnostic sonography.Imaging Findings: 1. What are BI-RADS 3, 4 and 5 lesions? 2. How do we diagnose BI-RADS 3, 4 and 5 lesions on US? 3. The five categories according to imaging-pathologic correlation are: Type A, concordant benign; Type B, discordant benign; Type C, concordant malignancy; Type D, discordant malignancy; Type E, high risk or borderline. 4. What are the diagnostic efficacy and the pitfalls in interpretation?Conclusion: In this pictorial assay, we categorized five forms of imaging-pathologic correlation in BI-RADS 3, 4 and 5 lesions on US, and described and illustrated their US and pathologic features. This classification of imaging-pathologic correlation in BI-RADS 3, 4 and 5 lesions on US will be of help in the efficacious categorization and in the accurate assessment of breast lesions on US.

C-119 Value of ultrasonic breast cancer screening in women with fibrocystic disease (FCD) D.V. Passynkov1, I.V. Kliouchkin2, O. Pasynkova1; 1Loshkar-Ola/RU, 2Kazan/RU (passynkov@mail.ru)

Purpose: To evaluate usefulness of ultrasonic breast cancer screening in women with FCD which results in increased breast density in mammography compromis-ing its sensitivity.Methods and Materials: Screening performed annually and included first clinical breast examination. Negative cases examined mammographically; then, in cases with 3-4 breast density (ACR 2005) and negative mammography, we performed ultrasonograhy (Medison SA8000EX). Totally 2815 women had both mammog-raphy and ultrasonic examinations (mean age 45.27 4.233 years varied from 22 to 56 years).Results: At mammography, breast density grade 1 was observed in 140 (4.97%) women with FCD, 2-308 (10.94%), 3-1630 (57.90%), 4-737 (26.18%). During ultrasonography, we found 43 lesions (BIRADS 3 - 17; BIRADS 4-5 - 26) that required biopsy. In these cases, breast cancer revealed in 14 women (12 of them previously classified as BIRADS 4-5, 2 - BIRADS 3). All of them were non-palpable and obscured at mammography. Mean size - 8.23 1.533 mm (6-23 mm); DCIS - 1 case, ductal carcinoma T1 - 11, lobular carcinoma T1 - 1, ductal carcinoma T2 - 1 case; 0 stage - 1 woman, I - 9, II - 5 cases. During the screening interval, 3 more cancers were revealed (all invasive ductal carcinomas T1). Overall sensitivity was 99.5%, specificity 32.6%.Conclusion: It is useful to add ultrasonography to screening in selected women with dense breasts. At the same time, such screening is expensive and has lim-ited sensitivity for DCIS and lesions smaller than 5-6 mm and reveals many false positive cases.

C-120 Ultrasound (US) and Doppler findings in intracystic breast tumors O. Catalano, A. Nunziata, M. Mattace Raso, L.A. Illiano, A. Siani; Naples/IT (tonikus@libero.it)

Purpose: Intracystic carcinomas represent 0.3-2% of breast malignancies and have several diagnostic peculiarities. We illustrate the US and Doppler findings in patients with breast tumours developing within cysts.Methods and Materials: We evaluated the US and Doppler findings in 23 women with intracystic tumours. Whole-breast scans were taken with high-resolution US, colour-DopplerUS and power-DopplerUS. We categorized several morphologic aspects, including cyst size, solid-to-cystic proportion, cyst shape, solid component

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shape, echogenicity of fluid component, echogenicity of solid component and evi-dence of shadowing or of enhancement. We assessed various vascular aspects, including flow presence within the solid component, flow entity, number of vascular poles, and spectral flow pattern.Results: Nine out of 24 women underwent US-guided fine-needle aspiration cytol-ogy and all were submitted to surgical resection. Final diagnosis was intracystic papilloma in 10 cases and intracystic carcinoma in 14. Papillomas typically appeared as oval-shaped cysts with a small, eccentric solid globe showing subtle flow signals. Thirteen carcinomas appeared as oval-shaped cysts with large solid globe and multipolar, diffuse signals. In one carcinoma the solid component had a diffuse, peripheral distribution. The resistive index could be measured in 5 papillomas, and showed a mean value of 0.43 while it was measurable in all carcinomas, showing a mean value of 0.71.Conclusion: Intracystic breast tumours show specific US and Doppler findings, allowing an effective differentiation of tumours from nontumoral complex cysts and of papillomas from carcinomas. The most relevant indicators for malignancy included high solid-to-cystic ratio, intense visualization, multiple vascular poles, and high resistive index values.

C-121 Applicability of contrast enhanced ultrasonography (CEUS) to the differential diagnosis of solid breast lesions D. Stanzani, M.C. Chammas, L. Chala, M.C.V. Campos, N. Barros, G.G. Cerri; São Paulo/BR (danistanzani@gmail.com)

Purpose: To evaluate color Doppler and CEUS in the differential diagnosis of solid breast lesions.Methods and Materials: Forty-eight lesions (palpable or nonpalpable) were visualized at gray-scale as solid masses and were prospectively evaluated with color Doppler before and after injection of a contrast agent. Lesion vascularity and the morphology of vessels on US scans were analyzed and were correlated with histologic results.

Results: Percutaneous biopsy revealed 25 malignant and 23 benign lesions. Morphologic analysis using gray-scale sonography and classified according the BI-RADS lexico showed sensitivity of 96%, and specificity of 34%, positive and negative predictive values of 61 and 88%, respectively. Considering Doppler so-nography, the sensitivity, specificity, positive and negative predictive values were, respectively, 72%; 78%; 78% and 72%. After contrast agent injection the sensitivity, specificity, positive and negative predictive values changed to 68%; 78%; 77% and 69%, respectively.Conclusion: Color Doppler was superior to CEUS and may be helpful in increasing the specificity of morphologic features analysis.

C-123 Computerized scheme for detection of masses in whole breast ultrasound images Y. Ikedo1, D. Fukuoka1, T. Hara1, H. Fujita1, E. Takada2, T. Endo3, T. Morita3, G. Lee1; 1Gifu/JP, 2Tochigi/JP, 3Nagoya/JP (ikedo@fjt.info.gifu-u.ac.jp)

Purpose: We have developed a computer-aided diagnosis (CAD) system for a large-volume breast cancer screening by ultrasonography. A computerized scheme for detection of masses in whole breast ultrasound images is proposed.Methods and Materials: 23 abnormal and 86 normal whole breast ultrasound images were employed. All images were acquired by the ASU-1004 whole breast ultrasound scanner (Aloka Co., Ltd., Japan). A whole breast image consisted of 84 slice images with 2 mm intervals. Edge directions and density difference between slice images were used for the initial detection of masses. Canny edge detector and watershed algorithm were employed for the edge detection and the segmentation of mass candidate regions. False positives (FPs) were reduced by use of rule-based technique and quadratic discriminant analysis. These methods were performed using five features including area, average density, position of center of gravity, difference of average density, and depth-to-width ratio.Results: The sensitivities before and after applying the FP reduction procedure were 91.7% (33/36) with 35.8 FPs per breast and 81% (29/36) with 3.8 FPs per breast (409/109).Conclusion: We developed a computerized scheme for detection of masses in whole breast ultrasound images. Edge directions and density difference were ef-fective for detection of masses. Five features for the FP reduction were useful to distinguish between masses and FPs.

C-124 Circumscribed solid breast masses increased in size during follow-up: Is biopsy necessarily prompted? Y.-M. Park, J.-S. Park, S.-J. Choi, J.-R. Juhn, S.-J. Lee, J.-H. Ryu, O.-H. Kim; Busan/KR (pymrad@yahoo.co.kr)

Purpose: To evaluate the histologic diagnosis of solid breast masses that showed benign morphology at the initial ultrasonography (US) and increased in size during follow-up, and to determine whether biopsy is necessarily prompted even if they still remain benign in morphology.Methods and Materials: This retrospective analysis included 41 patients (age range, 18-63 years; mean age, 39.3 years) with 47 solid breast masses that were designated as probably benign at the initial US and increased in size at follow-up US (mean, 13.2 months; range, 5-35 months). In 45 of 47 masses, either US-guided core needle biopsy (n=32) or surgical excision (n=13) was performed after perception of an increase in size. In the remaining two masses, follow-up with US (n=2) was performed.Results: Of 47 masses, forty still remained benign in morphology despite an in-crease in size and seven changed irregular in shape at follow-up US. All forty five lesions in which biopsy were performed proved benign. The remaining two lesions did not increase in size any more and the margins remained stable during the follow-up period (13 months and 26 months, respectively). No breast carcinoma was observed.Conclusion: The data suggest that if circumscribed solid breast masses show an increase in size at follow-up US, but still remain benign in morphology, biopsy can be deferred. More data, based on a larger series, are required to establish the clinical acceptability.

C-125 Quantitative evaluation of contrast-enhanced ultrasound in differentiating benign and malignant breast lesions F. Marchisio, A. Pecchi, N. Caproni, P. D’Alimonte, R. Battista, B. Canossi, P. Torricelli; Modena/IT (francesca.marchisio@gmail.com)

Purpose: To evaluate the role of quantitative parameters obtained with contrast-enhanced ultrasound (CE-US) in the differentiation of benign and malignant breast lesions.Methods and Materials: 40 patients with breast lesion classified as BI-RADS 3/4 at US evaluation underwent CE-US. A quantitative analysis of the enhancement was performed by assessing the following parameters: peak of contrast enhancement (%), time to peak (TTP=s), lesion regional blood volume (RBV) and flow (RBF) and contrast mean transit time (MTT=s). Unpaired t test was used to determine significance of CE-US parameters in differentiating benign and malignant lesions. The results of CE-US were compared with histological evaluation.Results: Pathologic examination showed 29 malignant and 11 benign lesions. Peak enhancement value at CE-US was higher in malignant than in benign tumors (p=0.006) (median value: 24.4%). Diagnostic accuracy, sensitivity, specificity, PPV and NPV were respectively 62%, 85%, 40%, 58% and 72%. RBF was higher in malignant tumors (p=0.002) (median value: 33). Diagnostic accuracy, sensitivity, specificity, PPV and NPV were 65%, 85%, 42%, 62% and 72%. TTP was shorter in malignant lesions (p=0.001). Diagnostic accuracy, sensitivity, specificity, PPV and NPV were 60%, 81%, 36%, 58% and 63%. RBV (p=0.05) and MTT (p=0.3) did not show significantly differences in the two groups.Conclusion: Quantitative CE-US parameters (peak, TTP and RBF) were found to be significantly different in malignant and benign breast lesions.

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Miscellaneous

C-126 Focal mammographic asymmetric densities: Clinical-pathological review A.S.R. Preto, A. Carneiro, M. Pimenta, F. Pimentel, J. Gonçalves; Porto/PT (sofiapreto@hotmail.com)

Learning Objectives: Describe the various types of asymmetric breast findings seen at mammography. Discuss the various benign and malignant differentials.

Discuss the role of clinical features and US in the assessment of focal asymmetric

densities seen at mammography. Pathological correlation will also be done.Background: Although there is clearly a wide variation in breast size and paren-chymal pattern, the breasts are generally symmetric structures with similar density and architecture. However, asymmetric breast tissue is encountered relatively frequently. It can and often is benign; nevertheless, an asymmetric area may indicate a developing mass or an underlying cancer. We present different types of asymmetric breast findings and appropriate imaging work-up. We also discuss and illustrate the imaging and pathologic features of various benign and malignant causes of focal asymmetric densities and distortions.Imaging Findings: The American College of Radiology (ACR) Breast Imaging Reporting and Data System (BI-RADS) defines four different types of asymmetric breast findings: asymmetric breast tissue, densities seen in one projection, archi-tectural distortion, and focal asymmetric densities. These lesions are frequently encountered at screening and diagnostic mammography and are significant because they may indicate a neoplasm, especially if an associated palpable mass is pres-ent. Once these lesions are detected, supplementary mammographic views and ultrasonography (US) can be a key aspect of work-up.Conclusion: A thorough knowledge of the patient’s clinical history, along with a fundamental understanding of the ACR BI-RADS lexicon and the role and limita-tions of breast imaging, will allow more accurate interpretation of these potentially perplexing soft-tissue findings.

C-127 Mammographic calcifications revisited A.S.R. Preto, A. Carneiro, S. Guimarães, F. Pimentel, J. Gonçalves, I. Amendoeira; Porto/PT (sofiapreto@hotmail.com)

Learning Objectives: Description of the several types of calcifications, according to BIRADS classification. Understanding the underlying pathophysiologic processes leading to the various types of calcifications. Tips on how to differentiate malignant from benign types.Background: Calcifications on the mammogram are relatively easy to perceive. There are three types of breast calcifications according to BIRADS classification: amorphous, pleomorphic or casting calcifications. We can also try to determine their site of origin: within the ducts (casting type), within the terminal ductal lobular units (amorphous and pleomorphic types) and outside the glandular tissue (miscel-laneous types). The main difficulty lies in perceiving the malignant nature of the process, if there is one.Imaging Findings: The amorphous calcifications are often round or “flake” shaped calcifications that are sufficiently small or hazy in appearance that can not be inserted the two groups ahead. The pleomorphic calcifications are usually more conspicuous than the previous and are of varying sizes and shapes that are usually less than 0.5 mm in diameter. The fine, linear or branching (casting) calcifications are thin, irregular calcifications that appear linear, but are discontinuous and under 0.5 mm in width. Their appearance suggests filling of the lumen of a duct involved irregularly by breast cancer. All can be associated with cancer, but there are par-ticular aspects which point in one direction.Conclusion: Our eyes are prone to bright focus of light. Radiologists should take advantage of that and educate. To be successful, this analysis requires a combina-tion of clinical, radiological and sometimes histological data.

C-128 TRAM (transverse rectus abdonimus myocutaneous) flap: Breast cancer recurrence C. Carneiro, S. Alves, A. Ferrão, A. Guimarães; Porto/PT

Learning Objectives: To present the imaging findings of breast cancer recurrence and other normal and abnormal postoperative appearances in the various types of reconstruction using TRAM flap.Background: Breast reconstruction with TRAM (Transverse Rectus abdominis myocutaneous) flap is commonly used in patients with modified radical mastec-

tomy for breast cancer treatment. Currently, physical examination is the accepted method of detecting recurrence in reconstructed breasts. However, this method is limited by the difficulty in distinguishing fat necrosis or postoperative changes from recurrence. A few investigations have found that imaging studies are useful in detecting recurrent cancer.Imaging Findings: The normal mammographic and ultrasonographic findings were: fatty appearance, surgical clips and surgical scars. Fat necrosis, calcifications and cancer recurrence are included in the abnormal appearances of TRAM flap.Conclusion: Mammography, ultrasound and MR images may contribute to the diagnosis of benign postoperative changes and recurrent breast cancer lesions before they become clinical visible.

C-129 Correlation of breast lesions detected with magnetic resonance imaging with targeted ultrasound M. Balaro, K. Dias, M. Jasbik, V. Freitas, A. Brandão, F. Kestelman; Rio de Janeiro/BR (mbalaro@ig.com.br)

Learning Objectives: Our intent was to determine if targeted ultrasound can be a reliable method to visualize additional lesions discovered on magnetic resonance. A second goal was to correlate the morphologic and dynamic characteristics of magnetic resonance imaging with targeted ultrasound.Background: Between November 1, 2006 and May 31, 2007, 25 patients with 31 additional lesions on magnetic resonance were submitted to targeted ultrasound at our institution. All the lesions were non palpable and occult in previous studies (mammography and ultrasound). All the breast ultrasound were performed with a high-frequency (12 MHz) linear transducer. Doppler and harmonic were also available.Imaging Findings: Magnetic resonance lesions were: 19 masses, 10 non-masses-like enhancement and 2 focus. The kinetic curves were: 19 persistent, 7 plateau and 5 washout. The mean diameter was 10.5 mm (range 6~20 mm). An ultrasound correlate was identified in 16 cases (64%) and 21 lesions (68%): 15 masses (79%), 4 non-masses-like enhancement (40%) and 2 focus (100%). The mean diameter was 10.5 mm (range 6~14 mm). Among the lesions without an ultrasound correlate there were: 4 masses (21%) and 6 non-masses-like enhance-ment (60%). The mean diameter of lesions without an ultrasound correlate was: 12.6 mm (range 8 ~20 mm).Conclusion: Targeted ultrasound is useful to correlate magnetic resonance ad-ditional lesions. Focus and masses were the lesions with stronger correlation. The diameter of lesions did not interfere with targeted ultrasound results.

C-130 Infection and inflammatory lesions of breast: Imaging and pathology correlations J. An, C. Han, J. Kang, E. Kim; Seoul/KR (jkan0831@hanmail.net)

Learning Objectives: To review the various cause of infection and inflammatory lesions in breast. To demonstrate the imaging findings of infection and inflammatory lesions of breast. To correlate the imaging findings with pathology.Background: Infection and inflammatory lesions are clinically common diseases. Women between the ages of 18 and 50 years are commonly affected and it can be lactational or nonlactational. Pain, palpable lesion, warmth, and erythematous skin change are common symptom and physical findings to be diagnostic; however, they overlap in various conditions. Imaging provides important information about location, extent, abscess formation, and guiding of interventional procedure. This exhibition illustrates various cases and pathology correlations.Procedure Details: We retrospectively reviewed the medical records and radiologic findings of the patients who had inflammatory symptoms and underwent imaging studies between March 2003 and August 2007. The diagnosis included lactational and nonlactational mastitis, granulomatous lobular mastitis, tuberculous mastitis, sparganosis infection, complication after injection mammoplasty, and inflamma-tory breast cancer.Conclusion: Infection and inflammatory lesions are commonly encountered in clinical fields. Therefore, the radiologist should be familiar with these conditions. The proper evaluation methods and interventional procedures are important for the pertinent management. Inflammatory breast cancer should be differentiated from the inflammatory lesions.

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C-131 Incidental breast lesions on computed tomography N. Goyal1, T. Barton1, V. Rachapalli2, S. Ramamurthy2, N. Jain2, S. Rashid2, N. Evans1; 1Newport/UK, 2Cardiff/UK (sidi.rashid@yahoo.co.uk)

Learning Objectives: 1. To characterise incidental breast lesions detected on CT of the thorax performed for other indications. 2. To define the changes that require further evaluation. 3. To reiterate the importance of prompt triple assessment in patients presenting in this manner.Background: MDCT and multiplanar reformatting have increased the detection of incidental breast lesions on chest CT. These changes are not well described in literature and their significance in many cases is uncertain. Detection of these lesions has resulted in an increased referral to the multidisciplinary breast clinic in our institution, leading to further imaging and intervention in some cases.Imaging Findings: The breast lesions seen on the CT are characterised depend-ing on the size, shape and margin of the lesion. The number of lesions, density in Hounsfield units and presence of calcification are also considered. Appearances are correlated with mammograms, ultrasound and pathology results where ap-plicable. This pictorial review suggests that there are certain features, which are specific for benign lesions, thus avoiding the need for further imaging. In addition, malignant lesions are also detected with specific features, which indicate that further assessment is required.Conclusion: Low density calcification and well-defined round or oval lesions sug-gest benign pathology and do not necessarily require further evaluation. Higher density, irregular lesions are associated with malignancy and require prompt as-sessment by a multidisciplinary team

C-132 Clinical usefulness of low-dose 64-channel multidetector-row CT in prone position for breast cancer patients B. Seo1, K. Cho2, O. Woo2, G. Son2, Y. Kim1, S. Kim2; 1Ansan City/KR, 2Seoul/KR

Learning Objectives: To present the clinical usefulness of low-dose 64-channel multidetector-row CT in breast cancer patients.Background: Breast CT includes not only the breast, but also the axillary nodes, lungs, and bones. Thus, it can be used to decide tumor staging in patients with breast cancer. However, the use of breast CT has been limited because of radia-tion hazard and image quality. Low-dose multidetector-row CT improves these problems. In addition, unlike breast MRI, in a prone position, high-quality images without compression of the breast tissues can be produced. This study shows the clinical experience of low-dose 64-channel multidetector-row CT in breast cancer patients.Procedure Details: A total of 127 serial images of 50 patients with breast can-cers were included in this study; 36 patients were scanned before treatment. CT scanning parameters were 120 mAs, 50 kVp, 16 x 0.625 mm collimation, 3 mm slide thickness, and 34 cm field of view. For dynamic scanning, we obtained three phase images: precontrast, 90 s delayed, and 300 s delayed. In 36 patients who underwent preoperative CT scanning, we evaluated tumor staging using TNM classification and AJCC staging and then correlated with pathological staging. In 14 patients who performed postoperative CT scanning, we evaluated the response after treatment.Conclusion: Low-dose multidetector-row CT in prone position is a feasible study for tumor staging and assessment of treatment response in breast cancer patients, with decrease of radiation dose.

C-133 Breast cyst: Is it always benign? N.M. Abdel Razek; Cairo/EG (naglaabdelrazek@yahoo.com)

Learning Objectives: 1. To describe the classic appearance of breast cysts (simple cysts) as well as the atypical patterns (complex cysts) using ultrasonography, so-noelastography, soft tissue mammography and MRI. 2. To analyse complex cysts enhacing the criteria that indicate maligancy on the different imaging modalities. 3. To describe the radiological appearance of the different pathologies of complex cysts including papilloma, intracystic phylloids and intracystic malignancy. 4. To describe the correlation between the lesion characterization and histopathology.Background: Simple cysts are usually benign; however, complex cystic lesions with septations and intracystic solid masses should be adequately analysed and biopsied, as the incidence of malignancy in such cases is 23%. The use of sono-elastography and dynamic MRI is very helpful to charcaterize these lesions, raising the suspicion of malignancy and calling for biopsy.Imaging Findings: Different criteria for simple and complex cysts will be described in detail, including the elasticity score by sonoelastography, the mammographic

criteria and the MRI diagnostic criteria of complex cysts, as well as enhancing septae and enhancing nodules, along with the dynamic enhancment curve.Conclusion: Mammography, sonoelastography and dynamic MRI are valuable imaging modalities in the characterization of complex cystic lesions.

C-134 Can lowering the maximum compression force in mammography reduce pain and still provide acceptable results? K. Chida, Y. Komatsu, M. Sai, A. Nakagami, K. Fujisawa, E. Sato, T. Yamashita, T. Yamada, M. Zuguchi; Sendai/JP (chida@mail.tains.tohoku.ac.jp)

Purpose: 1. To determine the maximum compression force that is less painful in mammography. 2. To discuss how much breast thickness is increased when the compression force is reduced. 3. To discuss the radiation dose and visual evaluation of mammograms when the breast thickness is increased. 4. To emphasize that breast compression pain is an important problem in screening mammography.Methods and Materials: We compared the breast thickness with compression pres-sures of 120 N (recommended force) and 90 N (reduced force) in 50 women [average age 49.9 10.7 years (mean SD)] who underwent screening mammography of the right and left breasts using mediolateral oblique (MLO) and craniocaudal (CC) views (n=200). The mAs value was recorded for radiographs using the RMI 156 phantom when 0- to 6-mm-thick acrylic plates were added. The image quality was also quan-tified objectively following the method recommended by the American College of Radiology using the RMI 156 phantom with and without an added acrylic plate.Results: 1. Women can better tolerate a compression force of approximately 90 N in mammography. 2. The breast thickness increased approximately 3 mm when the compression force was reduced to 90 N, and although the radiation dose increased approximately 20%, the image quality was identical to that with standard compression.Conclusion: Many patients experience breast pain with a compression force of 120 N. Consequently women find the examination unacceptable and are less likely to return for periodic screening mammograms. Reduced compression force mam-mography is acceptable in women whose breasts are particularly sensitive.

C-135 Mammography and MRI features of malignant lymphoma of the breast X.X.H. Wang, W.J. Peng; Shanghai/CN

Purpose: To investigate the features of MRI and mammography in 15 cases of breast lymphoma. Correlations between the imaging findings and histopathological classifications were explored.Methods and Materials: 15 patients (women; mean age, 45.7 years) with breast lymphoma were enrolled, mammography and MR scan were performed in 3 patients, 7 only had mammography, and 5 had MR examinations. 12 patients had primary breast lymphoma and 3 secondary involvements. All were proved histopathologically.Results: (a) Mammographic abnormalities: high-density and blurry-border mass (es) or architectural distortion without microcalcifications (n=5), asymmetric density (n=4). (b) MR findings: signal intensity on T1- weighted images were less than or equal to that of fibroglandular tissue and those on T2WI were higher or equal. Obvious homogeneous mass-like enhancement was seen with clear border. (c) Adjacent skin thickening was seen (n=3), diffused enlargement of the breast (n=5). Diffused skin edema, increase in parenchymal density, and axillary lymph-adenopathy were shown (n=5). (d) In 12 patients with primary breast lymphoma, lesions were classified as mass-like or nodular in 8 (66.7%), 3 with secondary involvement had diffused involvement of the breast manifested by ill-defined parenchymal densities which occupied most of the breast volume, with diffused skin edema. (e) Most of breast lymphomas were non-Hodgkin lymphoma (14/15, 93.3%). (f) 5 of 15 underwent treatment, 4 were partial response (regression of masses and skin thickening), and 1 was progressive.Conclusion: The imaging abnormalities of breast lymphoma varied from fairly discrete nodules, masses to diffused involvement of the parenchyma and skin. Mammography and MRI are useful for follow-up after therapy.

C-136 Diagnostic yield in telemammography C. Vilà Parera, F. Gras, X. Salvador, M. López, X. Martínez, R. Salvador; Barcelona/ES (fgras@cditarragona.com)

Purpose: To depict the real diagnostic value of breast image after compression-de-compression and compression-transmission, and establish the minimum standards for telemammography image reading, avoiding microcalcifications overlook.Methods and Materials: We compared 716 consecutive mammograms from 5th June

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to 23rd July, read in 5Mpx screens distributed in three settings: 1. directly capture from the workstation (considered the gold standard), 2. directly from PACS after compres-sion and decompression and 100 mbps net transmission, 3. reading after compression and 10 mbps net transmission and a final compressed output display. The 3 readers classified the mammograms into three results: No calcifications, benign calcifications and potentially malignant calcifications. 24 microcalcifications in the gold standard were considered for biopsy. The result was benign in 20 and malignant in 4 (1 atypical hiperplasia, 1 in situ carcinoma and 2 infiltrating ductal carcinoma).Results: The four malignant results were depicted in the second setting (compres-sion-decompression), and only two in the third setting (compression-transmission without decompression). They were evaluated using quadratic ponderation, but the series has too small figures to have statistical value.Conclusion: Nowadays in our country, transmission is an influence factor that limits the diagnostic yield, but compression and decompression has no effect on diagnosis, according to our results.

C-137 Breast MRI and breast SPECT: Are they alternative or mutually complementary to each other? V.S. Dekan, S.V. Serebryakova, T. Demshina, G. Trufanov; St. Petersburg/RU (dekanvs@mail.ru)

Purpose: Malignant breast neoplasms are on the first place in mortality and in last decade morbidity in EU countries increased 2-3% every year. The purpose is to assess diagnostic value of breast MRI and SPECT and their opportunity to supplement each other in establishing accurate diagnosis.Methods and Materials: 49 women were included in this study (mean age 52 years). In 34 patient malignant tumors of breast were evaluated and 15 women with benign lesions or without any pathology formed control group. All patients underwent X-ray mammography, MRI and SPECT. Verification was made by histological examination after biopsy. MRI was performed using dynamic contrast enhancing. SPECT was performed on dual head SPECT system 30 minutes after iv injection of 500 MBq of 99mTc-MIBI. Semiquantative analysis was the essential part of examination.Results: In all patients with malignant tumors, both MRI and SPECT were effective in evaluation of tumor site. 18 women in that group had enlarged axillar limph nodes, but only in 8 patients there was an evidence of malignant type of their enlargement and all 18 have shown pathological increased uptake of MIBI in lymphatic nodes that was confirmed by histological examination.Conclusion: Breast MRI and SPECT are effective methods of evaluation and characterisation of malignant breast tumors. Using both MRI and SPECT can help to avoid mistakes in staging such tumors on the basis of characterisation of involved regional lymphatic nodes.

C-138 Association between radiologists’ experience and accuracy in interpreting screening mammograms M. Maristany, F. Ferrer, X. Castells, J. Royo, J. Martinez, F. Macià, A. Solano, J. Sanchez, I. Vollmer; Barcelona/ES (86413@imas.imim.es)

Purpose: To determine how factors related to radiologists’ experience affect the accuracy of mammogram readings.Methods and Materials: We selected a random sample of screening mammo-grams from a population-based breast cancer screening program. The sample was composed of 30 women with histopathologically-confirmed breast cancer and 170 women without breast cancer after a 2-year follow-up. The 200 mammograms were read by 21 radiologists routinely interpreting mammograms (RRIM) and by seven readers who did not routinely interpret mammograms (RNRIM). All readers were blinded to the results of the screening. Diagnostic accuracy was calculated through sensitivity and specificity.Results: Average sensitivity in mammogram interpretation showed no differences between RNRIM and RRIM (84% vs 85%; p=.999) but specificity was significantly lower in RNRIM (56% vs 66%; p .001). Multivariate analysis based on routine readers alone showed that specificity was higher among radiologists who fol-lowed-up cases for which they recommended further workup (feedback) (OR=1.37; 95% CI=[1.03; 1.85]), those spending less than 25% of the working day on breast radiology (OR=1.49; 95% CI=[1.18; 1.89]), and those aged more than 45 years old (OR=1.33; 95% CI=[1.12; 1.59]); the variable of average annual volume of mam-mograms interpreted by radiologists was not statistically significant.Conclusion: Annual reading volume may not play a crucial role in determining diagnostic accuracy in screening mammogram interpretation, although specificity decreased in radiologists not routinely reading mammograms. Follow-up of cases for which further workup is recommended might reduce variability in mammogram readings and improve the quality of breast cancer screening programs.

Cardiac

MRI

C-139 Abnormal ventriculoarterial connections in the adult patient: From embryogenesis to the MR gantry B. Graca, M. Seco, P. Donato, F. Caseiro-Alves; Coimbra/PT (brunomiguel@inbox.com)

Learning Objectives: To describe the MRI appearance of congenital cardiovas-cular lesions of the ventriculoarterial segment in the adult patient. To discuss the contribution of MRI in the postoperative evaluation of these conditions. To review the embryology of the ventriculoarterial segment.Background: Anomalous development of ventriculoarterial connections can cause one or both of the great arteries to originate from the incorrect ventricle (complete transposition of the great vessels; double-outlet right ventricle), stenosis or atresia of the origins of the great arteries (tetralogy of Fallot; pulmonary atresia), or persistence of a common arterial trunk (truncus arteriosus). Most of these complex congenital heart diseases in the adult patient are incompletely evaluated by echocardiography and MRI is becoming the method of choice to depict the three-dimensional rela-tionship of the involved structures, allowing precise delineation of cardiovascular anatomy and quantitative assessment of left and right cardiac function, both in the pre and postoperative periods.Procedure Details: In this exhibit we describe and illustrate: 1. The embryology of the heart (focusing on the ventriculoarterial segment). 2. The MRI technique, appearance and postoperative evaluation of the abnormal ventriculoarterial connec-tions: 2.1 Complete transposition of the great vessels; 2.2 Double-outlet ventricle; 2.3 Tetralogy of Fallot; 2.4 Pulmonary atresia; 2.5 Truncus arteriosus.Conclusion: Knowledge of basic notions of cardiac embryology and awareness of the imaging features of these various conditions is essential to obtain the correct diagnosis, contributing to appropriate choice of patient treatment and follow-up after eventual surgery.

C-140 Effectiveness of cardiovascular MRI in operative/interventional decision making in patients with mitral stenosis A.J. Baxi, M.M.A. Siddiqui, R.K.V. Khattari, K.L. Tourani; Hyderabad/IN (ameyajbaxi@hotmail.com)

Learning Objectives: 1. To evaluate the reliability of planimetry method for estimat-ing mitral valve area in mitral stenosis by cardiovascular magnetic resonance imag-ing. 2. Assessment of myocardial viability, left atrial thrombus and other parameters that influence either operative or interventional management. 3. Comparison of the above parameters with 2D echocardiography.Background: Thirty cases of mitral stenosis diagnosed on 2D echocardiography, presenting to Care hospitals, Hyderabad, were subjected to cardiac MRI for comparative study.Imaging Findings: Mean MVA determined by MRI-planimetry was 0.968 0.37 cm² (range 0.48-2.02 cm²) and by 2D transthoracic echocardiography was 0.967 0.39 cm² (range 0.6-2 cm²). Two methods produced equivalent results. (p=0.005). Of the thirty patients, MRI showed left atrial thrombus in eight patients, of which six were missed on echocardiography.Conclusion: We demonstrated that planimetry of MVA by MRI is possible and reliable in mitral stenosis. We were able to avoid unnecessary angioplasty in eight patients be-cause of left atrial thrombus who then underwent successful open mitral valve surgery. Four patients who had viable yet dysfunctional myocardium underwent simultaneous bypass and open valve surgery. Cardiovascular MRI is an effective non-invasive examination that can be used in patients with mitral stenosis who have undergone sub-optimal transthoracic echocardiography due to poor window or associated mixed lesions. It can effectively assess left atrial thrombus, myocardial viability and other parameters that strongly influence operative or interventional management.

C-141 Postoperative MR imaging in cyanotic congenital heart diseases: Normal findings C. Méndez, R. Soler, E. Rodríguez, C. Martínez, I. Raposo; La Coruña/ES (esther.rodriguez@mundo-r.com)

Learning Objectives: To illustrate the most common surgical procedures performed on patients with cyanotic congenital heart diseases, along with the respective postoperative MR imaging findings normally seen in clinical practice.Background: Improvements in surgical techniques and medical treatment have

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lengthened the lives of patients with cyanotic congenital heart diseases more than ever. Cardiac MR imaging is an ideal technique for evaluating post-surgical morphology and function in these patients. An understanding of these surgical procedures and their postoperative appearance is a basic requirement to be able to identify normal findings.Procedure Details: This exhibit describes and illustrates with sketches and MR images the surgical extarcardiac (systemic arterial-to-pulmonary artery shunts, systemic venous-to-pulmonary shunts and pulmonary artery banding) and intra-cardiac procedures (patch closure of the ventricular septal defect and widening of the right outflow tract in tetralogy of Fallot, and physiologic and anatomic correction of transposed great arteries).Conclusion: To accurately document and interpret the morphological and functional postoperative MR appearance of cyanotic congenital heart diseases, knowledge of the wide spectrum of surgical palliation and repair procedures and familiarity with the dedicated protocols for performing MR imaging are needed.

C-142 Postoperative MR imaging in cyanotic congenital heart diseases: Complications R. Soler, C. Méndez, E. Rodríguez, C. Martínez, I. Raposo; La Coruña/ES (esther.rodriguez@mundo-r.com)

Learning Objectives: To understand and to identify the MR features of a wide range of postoperative complications after the most common surgical palliation and repair procedures are performed in patients with cyanotic congenital heart diseases.Background: Most patients with cyanotic congenital heart diseases who live to adulthood have undergone surgical palliation or repair. New technical develop-ments in MR imaging, along with the complexity of the surgery itself have led to the increasingly common use of MR in the postoperative evaluation of these patients. The postoperative complications appearing in connection with cyanotic congenital heart diseases constitute a new diagnostic challenge for the radiologists, requiring familiarity with the anatomical and functional complexities of palliative and correc-tive surgical procedures.Procedure Details: In this exhibit, we illustrate the morphological and functional appearance in MR images of a wide range of postoperative complications in cyanotic congenital heart diseases after palliative procedures (systemic arterial-to-pulmonary artery shunts, systemic venous-to-pulmonary artery shunts, pulmonary artery banding and Rastelli procedure) and the surgery performed to correct tetralogy of Fallot and dextro-transposition of the great arteries.Conclusion: The radiologists must be familiar with the morphologic and functional MR appearances of surgical complications in patients with palliated or repaired cyanotic congenital heart diseases to deliver an accurate diagnosis on which to base management decisions.

C-143 Cardiac MRI identifies and characterizes disease of the pericardium A.J. Misselt, S.R. Harris, E.E. Williamson, P.A. Araoz; Rochester, MN/US (misselt.andrew@mayo.edu)

Learning Objectives: To illustrate the utility of MRI in defining the anatomy and pathology of the pericardium. To describe various MRI techniques useful in evaluat-ing specific features of pericardial disease.Background: The pericardium is a bi-layered covering, which separates the heart from the remaining mediastinal structures and couples the cardiac chambers. Diseases of the pericardium are often subtle. MRI is well suited to evaluate the pericardium given its excellent temporal and spatial resolution and tissue charac-terization ability.Imaging Findings: MRI effectively defines the pericardial anatomy, including recesses, cysts, diverticula, masses, and congenitally absent portions. MRI also identifies pericardial effusion and can offer insight into the nature and etiology of the fluid. Pericardial thickening and enhancement, both features of pericarditis, are ably demonstrated using enhanced cardiac MRI. Perhaps most importantly, the outstanding temporal resolution of cardiac MRI allows cine viewing of the hearts motion, which facilitates the differentiation of contrictive pericarditis from restric-tive heart disease.Conclusion: Cardiac MRI is a powerful and clinically relevant tool for describing pericardial anatomy and identifying pericardial disease.

C-144 Clinical experience with whole-heart coronary MRA using 3 Tesla: Comparison with 64-slice MDCT Q. Yang, K. Li, R. Merges, J. Chen, J. An; Beijing/CN (yangqi3456@sohu.com)

Learning Objectives: 1. To introduce a new method for 3D whole-heart MR imaging of coronary arteries at 3 Tesla. 2. To describe the clinical applications of whole-heart coro-nary MRA at 3 T on a series of 32 patients and to compare it with 64-slice CTA.Background: 3 T has been shown to be a promising platform for performing coro-nary MRA due to the SNR gain over 1.5 T, however greater field inhomogeneity lowers the performance of SSFP. In this exhibit, we will describe how we got around the problems of SSFP by using the good old FLASH at 3.0 T to get high quality 3D whole-heart imaging.We will show the advantages and limits of this technique in comparison with 64 slice MDCT. The utility of whole-heart coronary MRA in the era of 64-slice MDCT will be discussed.Procedure Details: A total of 32 patients (18 males and 14 females) were imaged on a 3 T whole-body scanner (Trio+tim; Siemens Medical Solutions). The acquisition of whole-heart coronary MRA was completed in 29 patients with an imaging time averaged at 7.5 0.6 min.Coronary MRA procedure included: Whole-heart coverage; navigator-gated, ECG-gated, magnetization-prepared (fat saturation and non-selec-tive inversion pulse) FLASH sequence; slow infusion of contrast agent.Conclusion: Whole-heart coronary MRA imaging at 3 T in patients with coronary artery disease is feasible. Whole-heart coronary MRA also has high sensitivities for the detection of significant stenosis in comparison with 64-slice MDCT.

C-145 Cardiac MRI for evaluating various causes and clinical significance of paradoxical septal motion D. Kim1, J. Byun1, S. Choi2; 1Gwangju/KR, 2Bungdang/KR (kdhoon@chosun.ac.kr)

Learning Objectives: 1. To review the various causes and pathophysiology of paradoxical septal motion. 2. To demonstrate the various imaging characteristics of MRI of paradoxical septal motion. 3. To correlate MR findings with clinical ap-pearances and pathophysiologic findings.Background: Changes in the position and geometry of the ventricular septum occur when there is an acute or chronic imbalance between left and right ventricular loading conditions such as postoperative state of TOF, atrial septal defect, pulmonary throm-boembolism, mitral stenosis, constrictive pericarditis, and left bundle branch block.Procedure Details: We recruited patients who showed paradoxical septal motion on cardiac MRI between January 2004 and April 2007. All MR images were acquired with patients in the supine position by use of a 1.5-T MRI system (Intera CV release 10; Philips Medical Systems, Best, the Netherlands) with a flexible body array coil. Immediately after the injection of 0.2 mmol/kg of gadolinium contrast (Magnevist; Schering, Berlin, Germany; flow rate, 4 mL/sec), four-chamber and two-chamber views as well as contiguous short-axis images of the entire heart were acquired with steady-state free precession (SSFP) inversion recovery sequence. Authors retrospectively investigated the cause of paradoxical septal motion with MRI using SSFP cine images and reviewed on the basis of previous studies.Conclusion: 1. Understanding the various MR imaging findings of paradoxical septal motion is important for accurate diagnosis and proper management. 2. Cardiac MR imagings using SSFP cine are very useful for the early diagnosis of paradoxical septal motion.

C-146 Impact of trans-ventricular pressure on interventricular septal configuration F.A. Calabrese, M. Francone, M. Mangia, I. Iacucci, C. Catalano, R. Passariello; Rome/IT (i.laria2004@libero.it)

Learning Objectives: To review the functional interaction between the right and left ventricular chambers.To understand the role of cine MR sequences and the impact of respiration on the evaluation of ventricular coupling. To discuss how cardiac (constrictive pericarditis, pulmonary hypertension, cor pulmonale, severe pulmonary valve incompetence, cardiac mass) and extracardiac diseases (chirrosis, mediastinic neoplasm) influence the function of the interventricular septum.Background: The left and right ventricles are physically separated, but the two chambers are functionally bound. The position and shape of the ventricular sep-tum are determined by the loading conditions. Cardiac MR is an important tool for differential diagnosis and evaluation of cardiac and extracardiac disease, which determine ventricular coupling.Procedure Details: A CMR study that includes cine sequences is performed.Conclusion: In conclusion, through the study of cine sequences and the evaluation

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of the impact on respiration, CMR is able to analyse VSM and to correlate it with cardiac (constrictive pericarditis, pulmonary hypertension, cor pulmonale, severe pulmonary valve incompetence, cardiac mass) and extracardiac diseases (chirrosis, mediastinic neoplasm). The present study suggests a versatile use of cardiac MR in the visualization and dynamic evaluation of patients with ventricular coupling.

C-147 Emerging role of cardiac MRI in the pre-implantation assessment of patients who are candidates for cardiac resynchronization therapy V.G. Katsiva1, N. Kelekis2, O. Benekos2, P. Flevari2, C. Tsompanlioti2, N. Economopoulos2, D. Kremastinos2, A. Gouliamos2; 1Piraeus/GR, 2Athens/GR (kelnik@med.uoa.gr)

Learning Objectives: To illustrate the current concepts and concerns underlying the implementation of cardiac resynchronization therapy (CRT) in patients with heart failure. To outline MRI methods for quantitative assessment of mechanical ventricular dyssynchrony. To develop MRI-based criteria to improve patient selec-tion for CRT candidacy.Background: CRT is an established therapeutic option for patients with heart failure (HF), depressed left ventricular (LV) function, and a wide QRS complex, aimed to restore the normal ventricular activation pattern. The high percentage of non-responders to CRT (20-30%), however, demands additional criteria. The presence of LV dyssynchrony has been proposed as an alternative criterion and, currently, it is assessed with echo-Doppler methods. Two unique capabilities of MRI, namely, quantative analysis of the regional ventricular function and depiction of myocardial scar have been shown to be promising in this regard.Procedure Details: A total of 12 patients with HF, qualified candidates for CRT, 5 patients with HF, not qualified for CRT, and 7 age-matched normal subjects were examined with cardiac MRI (CMR) using the protocol of cine mode technique in the short axis encompassing the whole LV, MRI tagging technique at three short axis levels and late-enhancement technique. By using the standard segmentation model, regional wall thickness and circumferential strain measurements were obtained over the cardiac cycle at corresponding short axis basal and mid levels. Temporal and regional variance of both variables were calculated and indexes of dyssynchrony were generated. Additionally, the regional viability was determined.Conclusion: CMRI has the potential of being a standard method to assess CRT candidates.

C-148 MR phase contrast flow measurements: Quality assurance in clinical routine S. Pertschy, D. Hartung, R. Döker, B. Graumann, G.P. Meyer, M. Galanski, J.C. Lotz; Hannover/DE (pertschy.stefanie@mh-hannover.de)

Learning Objectives: To learn how MR flow measurements can be made more reliable in clinical routine by internal validation or additional measurements. To avoid most common errors or recognize phase errors that might not be correctable.Background: Phase contrast flow measurements are used for a broad variety of indica-tions, e.g. cardiac output, shunt quantification and assessment of valve insufficiency. Though it has been shown to be a stable and reliable method, there are sources of errors that can lead to significant deviations from true flow values. While some of these are readily detectable, like phase aliasing, others might go unnoticed if not sought after, like systematic phase shifts and phase errors induced by field inhomogeneity.Procedure Details: We present simple rules for flow measurements in and around the heart as well as the great vessels of the thorax that help to recognize possible phase errors in measurement. These rules include additional analyses of the same data-set as the target vessel, as well as additional flow measurements in the course of the target vessel. Where possible, simple ways to correct phase errors are shown. For phase errors that are not correctable with simple standard tools, clear criteria will be defined that would help to judge a PC-flow measurement as invalid.Conclusion: Quality assurance in phase contrast flow measurements is essential and can be done with a little extra time spent on data acquisition and analysis.

C-149 MRI assessment of genetic dilated cardiomyopathy in LMNA-mutations carriers M. Antila1, J. Koikkalainen2, J. Lötjönen2, T. Heliö1, S. Kivistö1, K. Lauerma1; 1Helsinki/FI, 2Tampere/FI (margareta.antila@kolumbus.fi)

Purpose: To characterize the cardiac functional parameters and myocardial late enhancement pattern in LMNA-carriers.Methods and Materials: 12 LMNA-carriers (representing 9 families) who were heterozygotes for one lamin A/C mutation (Ser143Pro, T1085deletion, Ala132Pro,

Arg190Tpr) that may cause dilated cardiomyopathy and 14 healthy controls were studied with a 1.5 T MR imager. The volumes, wall thickness and motion of both ventricles were assessed from cine images. The LMNA-carriers were evaluated with late enhancement imaging.Results: All carriers were in NYHA class I and had sinus rhythm. 6/12 carriers presented with first degree atrioventricular block. 5/12 LMNA-carriers were as-ymptomatic, palpation being the most common symptom. The carriers had higher BSA-corrected LVEDV (93 13 vs 80 20, p=0.005), LVESV (36 7 vs 24 7, p=0.003) and lower EF (61 6 vs 70 3, p=0.0003). The carriers had decreased regional wall motion at basal inferior, anterior and septal segments, and decreased thickening of apicoseptal segment. 7/12 carriers showed midwall late enhancement that represents myocardial fibrosis. Inferior segments were most commonly involved: fibrosis was also observed in anterior, septal and lateral walls.Conclusion: LMNA-mutations are the most common genetic defects in familial dilated cardiomyopathy. To our knowledge, this is the largest LMNA-carrier group described with MRI. MRI can be used for early diagnosis of cardiomyopathy in known gene carriers and for phenotyping different DCM subgroups. Left ventricular regional dysfunction is consistent with late enhancement in the basal segments.

C-150 Dynamic intraventricular gradient during dobutamine stress echocardiography: Is there a myocardial structural change? Evaluation by MRI P. Donato, M.J. Ferreira, B. Graça, S. Monteiro, R. Martins, L.A. Providência, F. Caseiro-Alves; Coimbra/PT (pombas@gmail.com)

Purpose: To assess left ventricle (LV) characterization by cardiac magnetic reso-nance (CMR) in patients with a dynamic intraventricular gradient (IVG) during the performance of dobutamine stress echocardiography (SE).Methods and Materials: We prospectively studied 22 patients with no history of myocardium infarction or myocardium revascularization, 15 of them with IVG. The characterization was made regarding the existence of myocardium areas of late enhancement, the relationship between the myocardium and the peripheral muscle concerning T2 intensity signal and T1 signal enhancement, ejection fraction (EF), cardiac mass and final diastolic volume of LV.Results: Late enhancement areas were seen in 66.7% of patients with IVG (n=10) and a normal myocardium appearance was seen in all patients without IVG (p 0.005). These late enhancement areas did not have a location suggestive of ischemic heart disease (mostly intramyocardial and/or subepicardial). In patients with areas of late enhancement, the IVG (134.0 75.9) was significantly different than patients without areas of late enhancement (52.7 72.8), p 0.02. No differ-ences were found between patients with and without a gradient concerning the relationship between the myocardium and the peripheral muscle T2 intensity signal and T1 signal enhancement, EF, cardiac mass and final LV volume.Conclusion: The development of an IVG during an SE can be related to structural changes in myocardium tissue, depicted by late enhancement on CMR. Further studies are required to decipher the mechanisms of myocardium adrenergic hyper responsiveness and the role of myocardium fibrosis in these patients.

C-151 Preoperative evaluation of cardiac morphology and haemodynamic changes in patients with septal defects: Comparison of MRI and EchoCG E.A. Mershina, T.S. Pustovitova, V.E. Sinitsyn, S.L. Dzemeshkevich; Moscow/RU (elena_mershina@mail.ru)

Purpose: To demonstrate the possibility of MRI to be the only modality for a preop-erative evaluation of cardiac morphology and haemodynamic changes in patients with suspected septal defects.Methods and Materials: 90 patients (m/f - 30/60, 15-75 years old, mean age - 44.5 years) with known or suspected septal defects (ASD/VSD - 66/24) were examined using EchoCG and MRI. Standard MRI protocol (spin-echo and cine-MRI) supplemented with PC MRI was performed at 1.0 T and 1.5 T imagers. CE MRI was performed in 5 cases for patients with PAPVC. Intraoperative findings were the standard of reference.Results: In patients with secundum and primum atrial septal defects, the results of EchoCG were correct in all the cases. MRI was more sensitive than EchoCG in visualizing of small (3-8 mm) septal defects, defects of sinus venosus (3 of 18 were not diagnosed by EchoCG), and congenital abnormalities (in 6 patients we could find PAPVC not defined by EchoCG). Pulmonary to systemic (Qp/Qs) flow ratio was calculated noninvasively using PC MRI. In 48 cases, septal defects (38 ASD, 10 VSD) have been surgically corrected. Preoperative Qp/Qs was 1.5-3.5. Three patients have been refused in operation due to severe pulmonary vascular changes, high pulmonary hypertension, and changes of shunt direction (right-to-left); Qp/Qs in those cases was 0.6-0.8.

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Conclusion: Septal defects may be accurately identified, localized, and quantified using cardiac MRI methods. MRI is more accurate than EchoCG in identification of small defects, diagnostics of sinus venosus, and visualization of partial anomalous pulmonary venous connection.

C-152 Image quality and reconstruction timing of dual-source CT coronary angiography: Impact of the heart rate Y. Wang, Z. Jin, Z. Zhang, L. Kong, L. Song; Beijing/CN (yiningpumc@hotmail.com)

Purpose: To evaluate the impact of patients’ heart rate (HR) on coronary CTA image quality (IQ) and reconstruction timing using a dual-source CT (DSCT) scanner.Methods and Materials: Ninety-five patients with suspected coronary artery disease (low HR group: HR 70 bpm, n=26; moderate HR group: HR 70 bpm to 90 bpm, n=37; high HR group: HR 90 bpm, n=32) were examined by DSCT (Siemens Somatom definition). No beta-blockers were administered before the scan. Images were reconstructed at 10-100% of the cardiac cycle in increments of 10% using single-segment reconstruction. Two readers independently assessed IQ of all coronary segments using a 3-point scale from excellent (1) to non-as-sessable (3).Results: The mean IQ was 1.31 0.55 for all HR. Mean IQ was significantly better for low HR group (1.08 0.27) than for moderate HR group (1.32 0.58) and high HR group (1.47 0.61) (both P 0.05). There was no significant difference between the latter two groups (P 0.05). Mean IQ was significantly better for LAD (1.01 0.10) than for LCX (1.15 0.39) and RCA (1.20 0.48) (both P 0.01). A total of 1.4% (19/1386) of coronary artery segments were considered non-assessable based on motion artifacts. In 74 patients (78%), optimal image quality was achieved within the same phase for all three main arteries. In HR 70 bpm, the best IQ was predominately in diastole (88%), but in HR 90 bpm, the best IQ shifted to systole in most cases (84%).Conclusion: DSCT allows for diagnostic IQ within a wide range of HR using single-segment reconstruction. With increasing HR, the time point of best IQ shifts from mid-diastole to systole.

C-153 Effectiveness of cine SSFP MR technique for the estimation of infarct size after acute myocardial infarction in comparison with contrast enhanced inversion recovery technique (CE-IR) E. Algeri, I. Carbone, H. Grazhdani, F. Ciolina, N. Galea, M. Basood, C. Catalano, R. Passariello; Rome/IT (emanuela_algeri@yahoo.com)

Purpose: To determine the presence and extension of myocardial infarct (MI) hyper-intensity at SSFP Cine MR and to compare findings with the delayed enhancement observed using inversion recovery sequences (CE-IR).Methods and Materials: We retrospectively analyzed cardiac MR exams performed on 37 patients with acute myocardial infarction. All patients underwent Cine MR followed by CE-IR at 10-15 minutes after the administration of 0.2 mmol/Kg of contrast medium. All examinations were performed on a 1.5 T MR scanner using the same scanning planes. MI size (quantified in grams), MI transmurality (using a 5 point scale) and signal intensity (SI) of the infarcted zone and of normal myo-cardium were calculated for Cine MR and CE-IR. CE-IR results were considered the reference findings.Results: Cine MR was able to identify the presence of MI in 31/37 cases. MI size measured at Cine MR was underestimated in 13.8% of cases on average compared to MI size at CE-IR. The mean SI of the MI area at Cine MR was 24,410, while the SI of normal myocardium was 925. In 9/31 cases Cine MR overestimated MI transmurality.Conclusion: SSFP Cine imaging is a valid method for MI identification and assess-ment of infarct transmurality providing information on both viability and wall motion.

C-154 Evaluation of hemodynamic effects of transjugular intrahepatic portosystemic shunt (TIPS) on cardiac function of patients with cirrhosis: Preliminary results with cardiac magnetic resonance (CMR) M. Francone, F. Calabrese, I. Iacucci, R. Lezoche, G. Lombardi, M. Merli, C. Catalano, R. Passariello; Rome/IT (marco.francone@uniroma1.it)

Purpose: Cirrhotic pts are characterized by a hyper-dynamic syndrome (HDS) with an increase of Cardiac Output (CO) and decrease of systemic vascular resistances. HDS may be associated with myocardial fibrosis (MF). The purpose of the present study was to demonstrate presence and eventually a worsening of HDS in pts who underwent TIPS, and to identify signs of MF using CMR as reference modality.

Methods and Materials: 18 pts with clinical diagnosis of cirrhosis were referred to our department for CMR evaluation before and within 10 days after TIPS im-plantation. A CMR study that included cine-SSFP imaging and VENC sequences was performed in all cases; late enhancement acquisitions were also used for detection of MF. Ejection fraction (EF), end-diastolic (EDV), end-systolic (ESV), CO and early (E) and atrial (A) transmitral flow velocities were determined before and after TIPS implantation.Results: In 18/19 (92%) pts CMR revealed HS. EF increased from 57.2% 3.3% to 68.15% 1.2% after 1 month (p 0.05); EDV from 104.8 mL 25 mL to 130.41 mL 18 mL (p 0.05); ESV from 39.1 mL 33 mL to 43.68 mL 25 mL; CO from 4.53 L/min to 5.91 L/min (p 0.05). Regarding indices of diastolic function, E wave increased significantly (p 0.05), however, because of a parallel increase in the A component, the E/A ratio did not show significant changes. A specific foci of enhancement were observed in 2 pts.Conclusion: In pts with advanced cirrhosis and refractory ascites TIPS allows significant portal decompression. However HDS can deteriorate and TIPS should be considered with caution in pts with limited cardiac reserve. For this reason, functional evaluation with CMR is useful before and after implantation of TIPS and may also allow detection of MF signs.

C-155 Atrial volumetry (AV) in patients with pulmonary arterial hypertension (PAH): Preliminary results on cardiac MR (CMR) F.A. Calabrese, M. Francone, R. Le Zoche, P. Lucchesi, C. Catalano, R. Passariello; Rome/IT (francescaantonella@interfree.it)

Purpose: PAH is a progressive disease characterized by raised pulmonary vascular resistance, which results in diminished right-heart function. CMR has superior spatial resolution compared with echocardiography to evaluate atrial volumetry. The aim of this study is to assess right atrial size and function in patients with PAH and to correlate with hemodynamic parameters.Methods and Materials: 19 selected patients with clinical diagnosis of PPH were referred to our department for CMR evaluation from a reference national center. In all cases, hemodynamic parameters derived from diagnostic right heart catheter-ization were available. An MRI study was performed, that included short axis and horizontal long axis cine-SSFP imaging. After data acquisition, diameters, function and atrial volume quantification were determined. Right atrial mass and volumetry were correlated with pulmonary arterial pressure (PAP).Results: Asymmetrical atrial enlargement was demonstrated in 16/19 (84%) patients and predominantly confined to right atrium. Volume and dimension of right atriuml correlated positively with RV mass (RVm) (r=0.67 p 0.001) and PAP (r=0.72 p 0.001) and inversely with RV EF (r=-0.69 p 0.05).Conclusion: Asymmetrical atrial enlargement was demonstrated and observed in most patients with PPT. Our data suggest a correlation between morphology and function of right atrium with pulmonary haemodynamics parameters.

C-156 Cardiac mass characterization using MR cine and late enhancement images F. Cohen, A. Jacquier, J.-Y. Gaubert, F. Thuny, P. Champsaur, J.-M. Bartoli; Marseille/FR (frederic.cohen@ap-hm.fr)

Purpose: To assess the value of MR cine sequences and late enhancement imag-ing after gadolinium chelate injection in the characterization of cardiac masses and evaluate their ability to discriminate between tumour and thrombus.Methods and Materials: Between January 2002 and August 2007, 1159 patients underwent exploratory cardiac MR imaging (1.5 T) in our institution; 56 patients in this consecutive series had cardiac masses. A final diagnosis was made in 41 patients (44 masses), 17 by histological analysis, 24 on the basis of clinical results and follow-up. All patients were explored using MR cine sequences and late enhancement sequences after injection of 0.1 mmol/kg of gadolinium chelate. All examinations were blinded and reviewed by two radiologists on the basis of a reading grid. A consensus was obtained if necessary, after evaluation of the inter-observer agreement using Kappa (k) analysis.Results: 23 of the 44 masses were thrombi, 18 were tumours and 3 were anatomi-cal variations. The most discriminatory signs for tumour diagnosis were: late mass enhancement (sensitivity=89% [65-99], specificity=96% [78-99]; k=0.81 [0.63-0.99]), and adjacent soft tissues infiltration (sens=55% [30-78], spe=100% [85-100]; k=0.93 [0.80-1]). Discriminatory signs for thrombus diagnosis were: underlying late myo-cardial enhancement (sens=78% [56-93] spe=94% [73-100]; k=1), and underlying myocardial thinning (sens=70% [47-87] spe=100% [81-100]; k=1). A false positive for late enhancement was a mobile infracentimetric pedicled thrombus. One false negative was an infracentimetric mobile fibroelastoma.

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Conclusion: MR cine sequences and MR late enhancement imaging are highly sensitive and specific in the characterization of cardiac masses, with good inter-observer agreement. Infracentimetric and mobile masses should be analysed with caution.

C-157 Long term therapy follow-up in patients with cardiac sarcoidosis via cardiac MRI M. Heller, S. Zangos, T.J. Vogl; Frankfurt a. Main/DE

Purpose: To evaluate the long term therapy outcome in patients with cardiac sar-coidosis using delayed enhancement cardiac MRI along with ventricular dynamic functional analysis.Methods and Materials: 30 patients with histologically proven cardiac involvement of sarcoidosis were evaluated. Every patient received an initial cardiac MRI before therapy and under therapy a 6 and 12 month follow-up. Evaluated endpoints con-sisted of the assessment of regional hypokinesias as well as a functional analysis such as ejection fraction, stroke volume, myocardial mass and cardiac index. Areas of late enhancement were localized in myocardial segments and along with the left heart function categorized in progressive disease ( 20% progress of the infiltration and 20% worsening of the left heart function), stable disease (between 20% progress and 20% regress), partial response ( 20% regress) and complete disappearance of late enhancement with normalizing of the left heart function.Results: 25 patients were evaluable. 12.5% (n=5) of the patients showed a complete disappearance of cardiac involvement, 37.5% (n=15) showed a partial response, and 17.5% (n=7) showed a stable disease. 2 patients died due to therapy refrac-tory heart arrhythmias, and 3 patients needed a heart pacemaker or received heart transplantation.Conclusion: Cardiac MRI is a fast and non-invasive method for therapy control and follow-up in patients with cardiac sarcoidosis.

C-158 Global and regional right and left ventricular function in adult patients with repaired tetralogy of Fallot: Assessment with CMR D. Piotrowska-Kownacka, L. Kownacki, M. Kusmierczyk, E. Kowalik, K. Mirosław, L. Krolicki; Warsaw/PL (dpiotrowska@plusnet.pl)

Purpose: In patients with congenital heart disease, it is important to quantify global and regional ventricular function. The aim of our study was assessment of global biventricular function as well as regional shortening in regions throughout right ventricle (RV) in adult patients with repaired tetralogy of Fallot.Methods and Materials: Into the study were included adult patients with repaired tetralogy of Fallot. All patients underwent CMR on 1.5 T scanner. CMR protocol included SSFP sequence in short axis view and 2 D myocardial tissues tagging in 4 chamber and short axis orientation. Dedicated software was used to analyze global and regional biventricular function. Harmonic Phase (HARP) method was used to analyze 2D myocardial tagging images.Results: 24 patients (M:14, F:10, age: 38.8 7.8) were included into the study. Right ventricular function was reduced significantly when compared to the LV (RVEF=48.1 9.9 vs LVEF=55.7 6.3; RVEDV=223 ml 100 vs LVEDV=182.8 ml 62; RVESV=121.7 ml 83 vs LVESV=83.5 ml 37). In 12 out of 24 patients RVEF was below 50%. Longitudinal shortening (LS) was decreased in the mid segment of RV free wall (16.2%) when compared to basal (21.5%, p=0.04) and apical (19.6 p=ns) segments. In contrast the mid septum (16.4) had greater LS than basal (13.3 p 0.05) and apical septum (13.9; p=0.06). Longitudinal shortening of the RV was lower than the normal range in all patients irrespective of global function.Conclusion: The study revealed RV regional shortening pattern for ToF patients. Decreased RV performance can be measured in ToF patient using CMR.

C-159 Late gadolinium-enhanced magnetic resonance imaging in non-compacted ventricular myocardium (NCVM) as potential expression of the disease severity E. Grassedonio, E. Cracolici, M. Galia, G. Lo Re, T.V. Bartolotta, M. Midiri, R. Lagalla; Palermo/IT (egrassedonio@gmail.com)

Purpose: The aim of this study was to investigate prevalence and distribution of MR imaging gadolinium enhancement in patients with known NCVM.Methods and Materials: Eight patients (4 male and 4 female; 15 4 years) with diagnosed NCVM were scanned with a Signa HD 1.5 T (GE, Milwaukee, USA). In all patients cardiac-gated T1 and T2 black-blood FSE images in short axis and in four-chamber horizontal long axis were obtained. Breath hold cine MR sequences (FIESTA) were performed covering the whole left ventricle (LV) in short-axis plane

and in four-chamber view. A segmented inversion-recovery fast gradient echo sequence (IR-FGE) was performed in the short-axis plane of the LV and in four-chamber-view after gadolinium injection.Results: Transmural Gd-enhancement was detected in 5/8 pts (62%). 19 of 136 (14%) segments were enhanced, more often at septal mid and apical ventricular levels. Scarring did not follow the coronary distribution. Number of enhanced seg-ments correlated with end-diastolic volume (r= 0.52), end-systolic volume (r=0.63) and with ejection fraction (r=0.76). Patients with higher number of involved enhanced septal segments and transmural extension more often had severe hypokinesia or akinesia (p=0.0001).Conclusion: In patients with known NCVM number of enhanced segments and segmental distribution of Gd-enhancement is evidenced more frequently in the septal mid and apical ventricular levels. Enhancement appears to be associated with impaired segmental and global contractility and systolic function. Thus, Gd-MRI may play a role in clinical arena of patients with noncompaction disease.

C-160 Hypertrophic cardiomyopathy: Evaluation with contrast enhanced MRI and stress MR with perfusion assessment T.J. Pereira1, P. Donato2, M.J. Ferreira2, L.A. Providência2, F. Caseiro-Alves2; 1V. N. Gaia/PT, 2Coimbra/PT (tjbmpereira@gmail.com)

Purpose: Hypertrophic cardiomyopathy (HCM) is a primary cardiomyopaty, which cause myocardial hypertrophy, with impaired diastolic as well as systolic function, narrowing of the left ventricular outflow tract and is a common cause of sudden death. The purpose of this study is to review the role of cardiac MRI (CMR) in the evaluation of patients with HCM, focusing in the detection of HCM-related scars and the use of stress MR with perfusion assessment.Methods and Materials: We reviewed a total of 29 patients (18 men, 11 women, and mean age 40 years) that underwent CMR from November 2003 till September 2007, with suspicion of HCM, CMR diagnosis of HCM or elevation of LV masse. CMR evaluated morphology, masse, function and tissue characterization (with emphasis of detection of late enhancement areas) of the left ventricle. In patients with suspicion of myocardial ischemia adenosine stress perfusion CMR was performed.Results: A total of 10 patients CMR had confirmed diagnosis of HCM. In this group, 9 patients were submitted to ce-MRI (7 showed myocardial scar depicted by intramyocardial late enhancement). In 3 patients was assessed the perfusion, revealing in all cases perfusion defects not related to coronary disease (confirmed by coronariography) or to the scar area. There was obstruction of the left ventricular outflow tract in 5 patients; in all patients (10) myocardial mass was increased (284 g of mean LV masse). In 7 patients the hypertrophy was asymmetric. In 5 patients CMR didn’t confirm the suspicion of HCM. Valvular pathology was the most frequent cause for the other patients with elevation of LV masse.Conclusion: CMR is a non-invasive, radiation free and reliable method for the evaluation of HCM, having the capability of visualize in vivo HCM-related scars that are potentially arrhythmogenic and a promising study to demonstrate myocardial ischemia in patients with pre-cordial pain.

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Multidetector CT

C-161 Dual source CT cardiac angiography: An A to Z guide for medical residents M. Diaz, C. Hernandez, B. Zudaire, M. Arraiza, G. Bastarrika, J.-I. Bilbao; Pamplona/ES (jibilbao@unav.es)

Learning Objectives: 1. To provide a comprehensive guide for residents on how to perform coronary angiography studies using Dual Source multislice CT (DSCT). 2. To define the principles that constitutes the basis for DSCT coronary angiography. 3. To describe, based on our professional experience, practical useful strategies that facilitate and optimize results.Background: Cardiac CT is constantly undergoing development. DSCT represents a step forward in coronary artery examination.Imaging Findings: Following A to Z color-coded format guide, the current prac-tice of cardiac DSCT is illustrated including: 1. Data acquisition parameters (in blue). 2. Postprocessing techniques (in red). 3. Image display (in green). 4. Image interpretation (in yellow).Conclusion: This presentation summarizes our experience with DSCT coronary angiography in routine clinical practice and presents a practical approach for resi-dents interested in non-invasive coronary imaging. By providing clear definitions of technical concepts on data acquisition, postprocessing techniques, image display, and image interpretation, this exhibit might simplify and optimize the learning pro-cess of professionals initializing in state-of-the-art DSCT cardiac imaging.

C-162 Primer of cardiovascular pharmacology for radiologists B. Graca, R. Teixera, A. Pereira, P. Donato, F. Caseiro-Alves; Coimbra/PT (brunomiguel@inbox.com)

Learning Objectives: Review the practical pharmacology of cardiovascular agents used in cardiac CT and MRI examinations.Background: In the daily practice of a cardiovascular imaging department one has to deal with specific pharmacological agents as their use is an essential part of performing a successful CT or MRI cardiac examination. Beta-blockers (to optimize the patient’s heart rate and limit motion artifact) and nitrates (to increase coronary artery diameters and improve visualization of the vessel) may be used in CT coronary angiography examination. In order to evaluate the significance of coronary stenosis, perfusion imaging is carried out under pharmacological stress induction by short time infusion of vasodilatators (adenosine or dipyridamole) or dobutamine. Proper usage of these drugs has to be adequate to patient’s clinical status and short-term adverse effects must be promptly managed.Procedure Details: The exhibit will describe the mechanism of action, indications, dosage, contraindications, adverse reactions and complications (with proper man-agement) of beta-blockers, nitrates, adenosine, dipyridamole and dobutamine. The content will be adapted to the practical needs of the radiologist performing MRI and CT cardiovascular examinations.Conclusion: The use of pharmacological agents is a critical part of study opti-mization in cardiac CT and MRI. Knowledge about the indications and adverse reactions is essential to adequately avoid and manage complications associated with these drugs.

C-163 Comprehensive assessment of type A aortic dissection by ECG-gated MDCT J.-N. Heo1, S. Jeon2, Y. Choi2, C. Park1, Y. Kim1, D. Park1; 1Guri-si, Gyunggi-do/KR, 2Seoul/KR (radjena@hanyang.ac.kr)

Learning Objectives: 1. To understand the advantage of ECG-gated MDCT in the assessment of type A aortic dissection. 2. To know the technical aspects of ECG-gated MDCT in the evaluation of type A aortic dissection.Background: Even though conventional non-gated CT provides valuable informa-tion in the assessment of type A aortic dissection, the evaluation of the tear site, involvement of dissection flaps to aortic sinus and coronary arteries is not easy due to pulsating motion artifacts. Using ECG-gating CT technique, it is possible to reduce the motion artifact of the ascending aorta and the heart, enabling assess-ment of these abnormalities. In addition, by multi-phase reconstruction of the image data during the systole and diastole, the motion of the flaps, aortic valve and the left ventricle can be assessed.Imaging Findings: The typical findings of aortic dissection at unenhanced CT are internal displacement of intimal calcification and high attenuation of the false lumen. At contrast enhanced CT, an intimal flap that separated the true lumen from

the false lumen is a diagnostic finding. Intimal flap is not seen clearly in non-gated CT due to pulsation motion artifact, but in ECG-gated MDCT, intimal flap is clearly identified. Also, intimal tear site, dynamic motion of the flaps, involvement of aortic valve are easily evaluted by ECG-gated MDCT.Conclusion: ECG-gated MDCT is a powerful tool in the evaluation of the aortic dissection, the aortic valve dysfunction, the coronary involvement of dissection, the dynamic change of intimal flap, and the post-operative change.

C-164 Coronary calcium scoring: How to avoid pitfalls K. Gruszczynska1, M. Rengo1, F. Pugliese1, W.B. Meijboom1, A.C. Weustink1, A. Rossi1, M.L. Dijkshoorn1, J. Baron2, N.R. Mollet1, A. Laghi3, P.J. de Feyter1, G.P. Krestin1; 1Rotterdam/NL, 2Katowice/PL, 3Latina/IT (kgruszczynska@poczta.onet.pl)

Learning Objectives: To identify the most common artifacts in coronary artery calcium (CAC) measurement by CT. To discuss the solutions to obtain a robust and reproducible CAC score for defining patient cardiovascular risk.Background: Coronary artery calcium (CAC) measurement in cardiac computed tomography has been used since 1990 in the assessment of cardiovascular risk. ACC/AHA considers the use of CAC measurement in asymptomatic patients with intermediate risk of CAD, as the results of CAC can reclassify the patient’s risk status and help to modify patient management. Possible pitfalls in CAC measure-ment in MSCT can alter the accuracy of scoring.Imaging Findings: The range of CAC measurement artifacts from the retrospec-tive analysis of 400 examinations performed with a 64-slice CT scanner will be presented. The most popular were: motion artifacts, which can lead to duplication of the imaged vessel and to overestimation of calcium score. Conversely, due to poor spatial resolution and insufficient contrast to noise ratio, small coronary branches may be overlooked with subsequent underestimation of total calcium score. Extra arterial cardiac calcifications (calcified cardiac valves, LV aneurysm and thrombi, pericardial calcifications, calcified lymphatic nodes), radio-opaque catheters, artificial valves and peacemakers produce streak artifacts increasing background noise.Conclusion: Appropriate recognition of artifacts in coronary artery calcium scoring helps avoid pitfalls and improves accuracy of the measurement.

C-165 Several factors negatively influence stent imaging in multidetector computed tomography-coronary angiography (MDCT-CA): How to recognize and reduce this “huge” problem F. Alberghina1, G. Runza1, F. Pugliese2, L. Damiani1, M. Midiri1, R. Lagalla1; 1Palermo/IT, 2Rotterdam/NL (filippoalberghina@hotmail.it)

Learning Objectives: To discuss the acquisition protocol and reconstruction algorithm, which provide optimal image quality of stented coronary arteries with MDCT-CA. To address artifacts and influence of different reconstruction parameters on the visibility and interpretability of in-stent lumen for MDCT-CA.Background: Why the analysis of small high-density stents is difficult: criteria and factors to keep in mind in the setting of the acquisition parameters in patients who underwent stent deployment and need follow-up by MDCT-CA.Imaging Findings: We report examples of the role of spatial and temporal resolution and signal-to-noise ratio: 1) Influence of attenuation intravascular value, convolution kernel, heart rate, window visualization, matrix and field of view. 2) Optimal setting for acquisition protocol and reconstruction algorithm. 3) Artifacts and pitfalls due to stent strut, surrounding disease and building material.Conclusion: We demonstrate that to know these factors and their role in decreasing image quality is essential in setting the best acquisition protocol and reconstruction algorithm, which provide optimal image quality of both stent and native coronary arteries. MDCT-CA is a sensitive technique, which allows a reliable assessment of stent lumen and in-stent restenosis, especially in stents with bigger diameter; nevertheless, stent imaging is still influenced by several factors.

C-166 Tips and tricks for interpreting and reporting a cardiac CT study: A step-by-step instruction S. Leschka1, H. Alkadhi1, F.T. Schmid2, P. Stolzmann1, L. Husmann1, B. Stinn2, B. Marincek1, S. Wildermuth2; 1Zurich/CH, 2St. Gallen/CH (sebastian.leschka@usz.ch)

Learning Objectives: 1. To present a systematic instruction for interpreting cardiac CT. 2. To illustrate the pitfalls in cardiac CT interpretation and provide practical remedies. 3. To comprehensively report results from cardiac CT.Background: Cardiac CT has entered the level of daily clinical practice in many institutions, worldwide. The implementation of cardiac CT in the guidelines of several

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national and international societies will highly increase the rate of patient referrals for cardiac CT in the near future. A systematic approach is one of the key factors for the comprehensive and expeditious evaluation of a cardiac CT study.Procedure Details: In this exhibit, we would like to share our experience gained from interpreting and reporting approximately 1,000 cardiac CT examinations per year. This instruction explains step-by-step, which post-processing procedures are useful, how to read a CT coronary angiography, how to describe a coronary artery lesion, and how to avoid false negative and false positive classifications. Pitfalls and practical remedies will be highlighted. Interpretation includes ventricular analysis, cardiac valves, and extra-cardiac structures.Conclusion: The information provided are primarily designed to support radiolo-gists, who have just begun performing cardiac CT in their institutions, and it may also provide some helpful hints to experienced interpreters of cardiac CT.

C-167 Impact of screening for coronary artery disease (CAD) using 64-slice CT in asymptomatic low to intermediate risk patients J. Hoe, M. Shahid; Singapore/SG (jhoe@pacific.net.sg)

Purpose: To determine prevalence of CAD and incidence of significant coronary artery stenosis (CAS), defined as 50% luminal diameter stenosis, in asymptomatic patients, and to determine if 64MSCT coronary angiography (CTCA) has a role in risk stratification.Methods and Materials: 647 asymptomatic individuals, with traditional coronary risk factors, underwent calcium scoring (CS) and CTCA. Based on the age-criteria of SHAPE guidelines, they were subdivided into two groups: Group-A of 526 individuals (M 45 yrs, F 55 yrs) and Group-B of 121 (M 45 yrs, F 55 yrs).Results: 375 individuals (72%) had CAD, either with CS of 1 or significant non-calcified CAS on CTCA in Group-A and 44 (27%) individuals in Group-B (p 0.05). Low CS ( 99) was found in 333 (63%) in Group-A and 116 (96%) in Group-B (p 0.05). Moderate CS (100-399) was present in 118 (23%) in Group A and in only 5 (4%) in Group-B. Very high CS ( 400) was in Group-A only (75 pts, 14%). 15 (3%) individuals with low CS of 99 in Group-A and 2 in Group-B had significant CAS on CTCA.Significant CAS without coronary calcification was present in at least one vessel in 13 (2%) patients of Group-A (9 SVD, 4 MVD), compared to 8 (7%) in Group-B.Conclusion: We detected an unexpected high prevalence of CAD in asymptomatic patients. Relatively high prevalence of non-calcified plaques in the younger patient, detected by CTCA is of clinical concern. CS and CTCA can be used for better risk stratification of low to intermediate risk asymptomatic patients.

C-168 Value of multi-slice CT in characterizing coronary atherosclerotic plaques: An animal study G. Shi, L. Yang, Q. Wang, J. Li, Q. Xu; Beijing/CN (jianying.li@med.ge.com)

Purpose: To evaluate the sensitivity and accuracy of multi-slice CT (MSCT) in detect-ing and characterizing coronary atherosclerotic plaques using animal models.Methods and Materials: The internal jugular vein of 40 Wistar male rats that had been fed with high fat forage for 8 weeks was exposed and fixed under anesthesia to introduce atheromatous plaque in aorta of mean caliber of 4.2 mm, similar to human coronary arteries. CTA scan was performed with 32-row MSCT. The rats were then sacrificed, vessels harvested and split. The position, size and shape of plaques were recorded according to endomembrane observation. Histopathologic examination was carried out with HE staining. CT images were analyzed by vessel analysis software of AW4.2 workstations to evaluate the formation of atheromatous plaque in aorta, including its size, shape, density and component of plaque, and the results were compared with those of in-vitro and histopathologic examinations.Results: 59 plaques were found by MSCT imaging and classified based on CT values according to the definition by Schroeder et al. These plaques included 50 soft plaques, 3 mixed plaques and 6 calcified plaques. Meanwhile, in the histopathologic examination, 67 plaques were found, including 56 soft plaques, 7 mixed plaques and 4 calcified plaques. The plaque detection rate of MSCT imaging was 88%.Conclusion: The study indicated that MSCT imaging, which is convenient and non-invasive, has a high detection rate for detecting coronary atherosclerotic plaques in the rodent aorta. This may have important implications in human coronary arteries based on the similarity in size.

C-169 Step and shoot: Preliminary experiences with a new scan type for CT-coronary angiography O. Klass, S. Wuchenauer, S. Feuerlein, M. Jeltsch, M.H.K. Hoffmann; Ulm/DE (oliver.klass@uniklinik-ulm.de)

Purpose: The standard approach for cardiac CT today is helical scanning provid-ing high spatial and temporal resolutions. Although multisegmental reconstruction enabled a dramatic improvement of temporal resolution, image quality still appears vulnerable and dose exposure has increasd substantially with additional detector rows. “Step and Shoot” is an alternative approach which relies on sequential axial acquisitions. The heart is covered in 4 to 5 axial rotations combined with prospective triggering. This allows a significant reduction of radiation exposure. The purpose of this study was to assess image quality generated with this protocol.Methods and Materials: 20 consecutive patients with suspected coronary heart disease scanned with “Step and Shoot” were matched to 20 patients scanned using standard helical CT angiography (Brilliance 64, Philips Medical Systems, Cleveland OH) using BMI, heart rate and sex. Radiation exposure was calculated for every individual patient and compared. Two independent observers using a scale from 1 to 5 assessed image quality for all coronary segments subjectively.Results: Radiation exposure in the “Step and Shoot” group averaged at 4.3 0.9 mSv, compared to 17.4 4.7 mSv in the standard helical scan acquisition (p 0.001). There were no significant differences of image quality for all coronary segments between the "Step and Shoot" and the helical scan groups.Conclusion: “Step and Shoot” is a promising approach for CT coronary angiog-raphy resulting in a significant reduction of radiation exposure with comparable image quality.

C-170 Detection of cardiac allograft vasculopathy by multi-detector CT and whole-heart MR coronary angiography H. Machida, S. Nunoda, M. Fujimura, E. Ueno, S. Morita, K. Suzuki, K. Otsuka; Tokyo/JP

Purpose: Cardiac allograft vasculopathy is a major complication that limits long-term survival of recipients of heart transplants. We compared the feasibility of using noninvasive multi-detector computed tomography (CT) and whole-heart magnetic resonance (MR) coronary angiography to conventional coronary angiography for detecting this vasculopathy.Methods and Materials: Of the 22 recipients of heart transplants who underwent conventional angiographic screening between December 2003 and July 2007, six had only multi-detector CT; nine, only MR angiography; and seven, both noninvasive modalities (three for 16-detector CT and ten for 64-detector CT). The coronary arte-rial tree was divided into 9 segments. We compared detection of the vasculopathy by coronary segments between 16- or 64-detector CT or MR angiography and conventional angiography as a reference.Results: The vasculopathy was detected in 38 of 198 segments by conventional angiography, 18 of 117 by multi-detector CT, and 14 of 144 by MR angiography. Sensitivity of multi-detector CT for detecting the vasculopathy was 68%, and speci-ficity was 97%. Especially for 64-detector CT, sensitivity was 89% and specificity, 98%. For MR angiography, sensitivity was 58% and specificity, 100%. Six false-negative segments were revealed by 16-detector CT, one by 64-detector CT, and ten by MR angiography. These false-negative segments resulted from the distal lesion or motion artifact.Conclusion: The use of multi-detector, especially 64-detector, CT is feasible for detecting cardiac allograft vasculopathy, whereas MR angiography currently shows limited sensitivity.

C-171 Anatomical remodeling of the left atrium in paroxysmal atrial fibrillation by multislice CT in comparison with chronic atrial fibrillation and normal sinus rhythm N. Funabashi1, K. Nakamura1, M. Uehara1, Y. Shiina1, T. Murayama1, H. Takaoka1, K. Suzuki2, M. Terao2, Y. Mita2, F. Maeda2, M. Ueda1, I. Komuro1; 1Chiba/JP, 2Tateyama/JP

Purpose: Anatomical remodeling of the left atrium (LA) in subjects with paroxys-mal-atrial-fibrillation (PAF), chronic-atrial-fibrillation (CAF) and normal sinus rhythm (NSR) were examined by MSCT.Methods and Materials: 141 subjects (47 subjects each with CAF, PAF, and NSR, mean ages: 70, 66 and 64 years, respectively) underwent MSCT (Light Speed VCT, or Ultra 16, GE) to evaluate the pectinate muscles (PM) in the left atrial appendage (LAA), LAA enlargement, and contrast defect in the LAA in the early phase.

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Results: Well-developed PM, poor PM, and no PM were observed in 18%, 41%, and 41% (CAF), 58%, 24%, and 18% (PAF), and 88%, 12%, and 0% (NSR), respectively. CAF subjects with no PM had longer periods of CAF than those with developed PM. LAA enlargement and contrast defects in the LAA were observed in 88% and 59% (CAF), 41%, and 24% (PAF), and 0% and 0% (NSR), respectively. Wall thickness and the ratio of abnormal late enhancement of the LA wall, indicating fibrosis or inflammation, were 2.1 0.4 mm and 0% (CAF), 3.0 0.7 mm and 22% (PAF), and 2.1 0.6 mm and 0% (NSR), respectively. These values were significantly greater in PAF than in CAF and NSR.Conclusion: Anatomical differences were observed between subjects with PAF, CAF and NSR. Wall thickening and late enhancement of the LA wall suggest the anatomical remodeling of the LA in PA, which may represent an initial stage of LA remodeling. During transition from PAF to CAF, the LA wall may be stretched and, ultimately, LA wall thickness may decrease in CAF.

C-172 64-slice CT imaging of coronary artery lesions in patients with unstable angina Y. Wang, Z. Jin, L. Kong, Z. Zhang, L. Song, S. Zhang; Beijing/CN (yiningpumc@hotmail.com)

Purpose: To investigate the characteristics of coronary artery lesions of patients with unstable angina (UA) by using 64-slice CT.Methods and Materials: 44 patients (25 male; age 62 12 years) with UA underwent both ECG-gated CT angiography (CTA) (120 kV, 850 mAs, 0.33 s-rotation time, 64 x 0.6 mm collimation, Siemens Somatom Sensation 64) and invasive coronary angiography (ICA). All coronary segments were assessed using syngo circulation software and graded as: no disease, mile disease (stenosis 50%), and significant disease (stenosis 50%). Coronary plaques were classified as calcified, non-calci-fied, and mixed plaques.Results: All the patients and 634 of 660 (96%) coronary segments showed diag-nostic image quality. ICA revealed significant disease in 82% (36/44), mild disease in 7% (3/44), and no disease in 11% (5/44) of patients. On a per-segment basis, ICA identified overall 107 significant stenoses. 101 of these stenoses were detected on CTA: 51 (50%) with non-calcified plaques, 3 (3%) with calcified plaques and 47 (47%) with mixed plaques (36 non-calcified dominant and 11 calcified dominant plaques). CTA also detected 55 % (6/11) mild stenoses with non-calcified dominant plaques, and 45% (5/11) with calcified dominant plaques. The sensitivity, specificity, PPV and NPV of 64-slice CT for detecting significant stenosis were: 94.4% (101/107), 98.5% (519/527), 92.7% (101/109), and 98.9% (519/525), respectively.Conclusion: Patients with UA have more stenoses related to non-calcified plaques than to calcified plaques. 64-slice CTA with high accuracy in diagnosing significant stenosis has the potential to identify high-risk patients who need to undergo ICA.

C-173 Assessment of myocardial viability in humans using contrast-enhancement MDCT: Effect of time and kinetics of iodine contrast medium in LV blood, normal and infarcted myocardium A. Jacquier1, N. Amabile1, F. Cohen1, J.-M. Bartoli1, D. Revel2, P. Croisille2; 1Marseille/FR, 2Lyon/FR (alexis.jacquier@ap-hm.fr)

Purpose: Our purpose was to define the optimum delay between injection and MDCT image acquisition to characterize infarcted myocardium and to assess the iodine kinetics relative parameter in LV blood, normal and infarcted myocardium.Methods and Materials: Nineteen patients were prospectively included after acute myocardial infarction. Each patient had an MDCT acquisition before, 5 and 10 min after injection of 1.5 ml/kg iodine and contrast-enhanced MRI 5 and 10 min after injection of 0.2 mmol/kg gadolinium chelate. We assessed qualitative and quantitative image quality, infarct extent and iodine kinetics relative parameter ( HU and HUratio).Results: There was good agreement between the areas of hyper enhanced myocar-dium located on the MDCT and the occluded vessel located on the coronary angiogram (k=0.9). On contrast-enhanced MDCT 5 min after injection SNR was significantly greater than the 10 min measurement in LV blood (28 1 at 5 min to 21 1 at 10 min; P=0.0007), normal myocardium (18 1 to 15 1; P=0.0009) and hyper enhanced myocardium (24 1 to 20 1; P=0.004). MDCT image quality was significantly better 5 min (3.2 0.1) after injection compared with 10 min (2.8 0.2, P=0.01, k=0.4). There was no significant difference between MRI and MDCT in terms of the infarct extent measurement. The

HUratio value increased between 5 min (0.83 0.01) and 10 min (0.93 0.01; P=0.01) after iodine injection, suggesting a slow wash-in in the injured myocardium.Conclusion: Contrast-enhanced MDCT is useful in the detection and characteri-sation of acute myocardial infarction. Contrast-enhanced MDCT performed 5 min after injection give a higher SNR and image quality than the 10 min time point with no difference in the extent of infarct measurement.

C-174 Diagnostic accuracy of 64-row gadolinium-enhanced CT coronary angiography P. Carrascosa1, C.M. Capuñay1, A. Deviggiano1, M. Bettinotti2, A. Goldsmit2, J. Carrascosa1, M.J. Garcia3; 1Vicente López/AR, 2Buenos Aires/AR, 3New York, NY/US (investigacion@diagnosticomaipu.com.ar)

Purpose: To evaluate the diagnostic accuracy of gadolinium enhanced 64-row MDCT coronary angiography and compare the results with digital angiography (DA).Methods and Materials: Eighteen patients with known or suspected CAD under-went DA and 64-row MDCT coronary angiography with gadolinium within the same week. A maximum dose of up to 0.4 mmoL/kg of body weight of gadolinium was injected. A stenosis above or equal 50% was considered a positive finding and a stenosis under 50% as a negative finding. MDCT results were matched with DA findings. To evaluate renal function, the primary variable was the change in serum creatinine level 48-hours after MDCT angiography. Seventeen segments were analyzed in each patient. The 95% confidence intervals for the proportions were calculated by the exact binomial method.Results: Mean baseline and 48-hours serum creatinine in the study patients was 0.95 mg/dL ( 0.2 mg/dL) and 0.97 mg/dL ( 0.2 mg/dL), respectively. The patient's heart rate ranged between 41-69 bmp (mean 53). There were a total of 289 coronary segments in the 18 patients studied. 283/289 segments were evaluable, 31 of which had a stenosis 50% by DA. The average level of enhancement in the proximal coronary lumen was 201.7 HU 22.44 HU. Sensitivity, specificity, positive and negative predictive values were 90.32, 96.83, 77.78 and 98.79%, respectively. The agreement of coronary stenosis between MDCT and DA was 94.11% (272/289).Conclusion: These results showed good correlation with DA findings and offer an alternative diagnostic method for patients with iodine contrast contraindications.

C-175 Quantitative myocardial perfusion evaluation with MDCT P. Carrascosa, C.M. Capuñay, J. Vallejos, E. Martín López, A. Deviggiano, J. Carrascosa; Vicente López/AR (investigacion@diagnosticomaipu.com.ar)

Purpose: To evaluate the ability of multi-detector computed tomography (MDCT) to quantify the different enhancement patterns during myocardial perfusion evaluation.Methods and Materials: Forty-five patients were studied. Contrast-enhanced rest and dipirydamole stress 16 row-dectector CT and stress/rest 99 mTc sestamibi SPECT were performed. Regional myocardial segments were classified by MDCT and SPECT as normal (NoS), ischemic (IS) or necrotic (NeS). NeS was observed as myocardial perfusion defect in both rest and stress scans; IS as myocardial perfusion defect only in stress but not in rest scan. Quantitative analysis was assessed by tracking tissue density of the myocardial region of interest and was correlated with MDCT qualitative findings. ROC curve analysis was used to define cut-off points between the different enhancement patterns.Results: The densities of the NeS in rest (43.19 23.11 HU) and stress (44.34 22.96 HU) scans were significantly lower than NoS in both rest (96.93 21.86 HU, p 0.001) and stress (93.23 22.31 HU, p 0.001) scans, re-spectively. The density of the IS in stress scan (63.78 24.15 HU) was significantly lower than NoS (93.23 22.31 HU, p 0.001) and significantly different from NeS (44.34 22.96 HU, p 0.001). In rest scan, no significant difference was found in density between IS (88.41 23.31 HU) and NoS (96.93 21.86 HU, p=0.14). Dur-ing rest scan, the cut-off point between NoS and NeS was 63 HU. While during stress scan, the cut-off point between NoS and IS was 68 HU, and between IS and NeS was 57 HU.Conclusion: Different myocardial perfusion patterns can be characterized and quantified accurately with MDCT.

C-176 Myocardial bridging and related coronary atherosclerotic burden by 64-slice CT coronary angiography L. La Grutta1, G. Runza1, V. Alaimo1, L. Damiani1, F. Alberghina1, G. Lo Re1, F. Cademartiri2, M. Midiri1, R. Lagalla1; 1Palermo/IT, 2Parma/IT (ludovicolagrutta@hotmail.it)

Purpose: To evaluate the correlation between bridged coronary segments and atherosclerotic disease in patients who underwent 64-slice CT Coronary Angi-ography (CT-CA).Methods and Materials: 96 patients (77 male, mean age 60 11) who underwent 64-slice CT-CA for suspected or known coronary artery disease were reviewed for myocardial bridging. Segments proximal and distal to the bridging were evaluated for atherosclerotic plaques. Cross-sectional imaging, MPR, MIP, and VR were employed to display myocardial bridging and related atherosclerotic burden.

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Results: 29 patients (30%, 24 male, mean age 58 12) presented single (86%) or double (14%) myocardial bridging with variable length ( 1 cm in the 48%, 1-2 cm in the 40%, 2 cm in the 12%). Superficial (76%) or intramyocardial (24%) bridges were detected. Myocardial bridging was frequently localized in the mid-distal seg-ment of the left anterior descending artery (93%). Coronary segments proximal to the bridge presented no atherosclerotic disease (n=7), positive remodelling (n=4), wall irregularities (n=4), 50% stenoses (n=9), 50% stenoses (n=6), or occlusion (n=3). 4 non calcified, 13 mixed, and 9 calcified plaques were detected. Assessable distal segments (61%) presented the following atherosclerosis extent: absence of disease (n=11), no significant lesions (n=8), and 50% stenosis (n=1).Conclusion: 64-slice CT-CA is a reliable method to non-invasively demonstrate myocardial bridging and related coronary atherosclerosis burden because of the high spatial resolution and flexible post-processing tools. 64-slice CT-CA provides new insight regarding atherosclerosis distribution in segments close to myocardial bridging that points out the link between a low shear stress and plaque formation.

C-177 Radiation induced DNA double-strand breaks in cardiac CTM.A. Kuefner1, J. Hamann1, M. Wiederseiner1, S.A. Schwab1, K. Anders1, S. Achenbach1, W.A. Bautz1, M. Lobrich2, M. Uder1; 1Erlangen/DE, 2Homburg a.d. Saar/DE (michael.kuefner@idr.imed.uni-erlangen.de)

Purpose: In computed tomography (CT) of the heart, patients are exposed to high radiation doses. It is difficult to compare doses of different scanners or examina-tion protocols. Therefore, it was our aim to establish a method for biological dose estimation in cardiac CT patients.Methods and Materials: Lymphocytes were isolated from blood samples of 20 patients and examined with a standard protocol using a 64-slice or dual-source CT scanner. Double-strand breaks (DSBs) were visualised by immunofluorescence microscopy after staining against Gamma-H2 AX. Dose equivalent was estimated by relating in-vivo number of DSBs to values of an individual in-vitro irradiation at 50 mGy.Results: Dose length product (DLP) ranged from 508 to 1700 mGy*cm. Number of radiation induced DSBs 30 minutes after CT ranged from 0.15 and 0.71 per cell, dose equivalent from 15.6 to 44.9 mGy. Both showed a correlation to DLP (R2=0.43 and 0.37, respectively). By using ECG-pulsing for dose reduction DLP, number of DSBs and dose equivalent was diminished up to 50%. Additional calcium scoring elevated dose equivalent up to 20%. Within 2.5 hours after exposure, more than two-thirds of DSBs disappeared in-vivo and in-vitro.Conclusion: Gamma-H2 AX immunofluorescence microscopy is a reliable method for biological dose estimation in cardiac CT. High damage levels can be found 30 minutes following exposure, but DSBs are repaired quickly. The influence of pa-tients’ individual factors (e.g. heart rate, body mass index) and scanning parameters (e.g. tube voltage, pitch) will be evaluated in further experiments.

C-178 Effect of preoxygenated breath holding on heart rate variability N. Karunanithy, E. Nicol, M.B. Rubens, S.P.G. Padley; London/UK (nara121@doctors.org.uk)

Purpose: In patients undergoing cardiac CT examinations, a heart rate of 60 beats/minute and minimal heart rate variability is thought to yield optimum image quality. The aim of this study was to determine the effect of pre-oxygenation on heart rate and heart rate variability.Methods and Materials: Double blind study involving 16 volunteers (8 male: 8 female) aged 24-47 years. The subject lay on the CT scan table but did not undergo a CT examination. The subject inhaled gas A for 2 minutes and 30 seconds during quiet respiration. A 30 second ECG recording in inspiration was obtained. After a 30 sec-ond interval of quiet respiration, a further 30 second ECG recording was obtained in expiration. The process was repeated with gas B. Half the subjects had gas A followed by gas B (AB group) and the other half gas B followed by gas A (BA group).Results: Following data analysis, it was revealed that gas A was oxygen and gas B air. Subjects inhaling gas B (air) had a significantly higher heart rate compared to gas A (oxygen) during inspiration (p=0.002 CI 1.22 to 5.41) and expiration (p 0.001 CI 1.59 to 3.41). There was no statistically significant difference in the heart rate between the AB and BA groups. There was no statistically significant difference in the heart rate variability between gas A and gas B.Conclusion: Pre-oxygenation has been shown to reduce heart rate. However the role in reducing heart rate variability has not been substantiated in this study.

C-179 Dual source CT coronary angiography improves image quality in morbid obese patients compared to 64-section CT coronary angiography B. Stinn1, S. Leschka2, F.T. Schmid1, M. Thurnheer1, B. Schultes1, S. Wildermuth1; 1St. Gallen/CH, 2Zurich/CH (sebastian.leschka@usz.ch)

Purpose: To assess image quality of CT coronary angiography (CTCA) in morbid obese patients comparing dual source CT (DSCT) with previous 64-section CT technology (64CT).Methods and Materials: CTCA was performed clinically indicated in 150 patients (92 men, mean age 61 12years). 75 patients underwent 64CT and 75 patients underwent DSCT. For each CT scanner type, 25 patients had morbid obesity (body mass index (BMI) 35 kg/sqm) and 50 patients had normal weight or overweight (BMI 30 kg/sqm). DSCT in obese patients was performed using a dedicated scanning protocol supplied with the CT system. Image quality of each coronary segment was evaluated by two independent radiologists using a 4-point Likert scale (1: excellent; 4: not-evaluative).Results: Overall image quality was significantly better with DSCT (1.60 0.85) compared to 64CT (1.69 0.91; p 0.05). While there was no significant difference in image quality in normal-weight or overweight patients (64CT: 1.58 0.80; DSCT: 1.60 0.75; p=0.12), DSCT significantly improved overall image quality in obese patients (64CT: 2.13 0.95; DSCT: 1.88 0.98; p 0.001). The rate of not-evaluative coronary segments in morbid obese patients was significantly higher with 64CT (6.9%; 24/347) than with DSCT (4.1%; 14/338; p 0.01). Additional factors influenc-ing image quality were comparable in both obesity groups including BMI (64CT: 38.0 1.8 kg/m²; DSCT: 41.1 4.9; p=0.10), mean heart rate (64CT: 68.9 13.4; DSCT: 76.4 13.7; p=0.09), and calcium score (64CT: 68 77; DSCT: 82 173; p=0.32).Conclusion: DSCT significantly improves image quality in morbid obese patients compared to the previous 64CT. The ability to image patients with high BMI is an ever growing concern in view of the increased prevalence of obesity.

C-180 Assessment of coronary artery bypass grafts by 64 slice multidetector computed tomography I. Elía, A. Batista, A. Lainez, J. Estornell, A. Núñez, V. Hervás; Valencia/ES

Purpose: Although computed tomography has shown high diagnostic accuracy in the non-invasive assessment of major epicardial coronary arteries, only few studies have evaluated its reliability to assess coronary artery bypass grafts. The aim of this study is to determine diagnostic accuracy of 64 slice multidetector computed tomography in the assessment of coronary grafts.Methods and Materials: We prospectively evaluated 34 patients with previous coronary artery bypass graft surgery (98 coronary grafts) and clinical indication for angiographic graft assessment. All patients were in sinus rhythm with heart below 75 bpm. A 64 detector scanner was used for non-invasive assessment of coronary grafts with a slice thickness of 1.2 mm. Diagnostic accuracy of computed tomography in non-invasive assessment of significant lesions (diameter reduction more than 50% or occlusion) in coronary artery bypass grafts was evaluated by comparison with the results obtained by conventional angiography.Results: A total of 98 grafts were evaluated, (40 arterial and 58 venous) 65 (84.6%) were visualized by conventional angiography and 68 (69.38%) by 64 multidetector computed tomography. Arterial grafts showed sensitivity and specificity of computed tomography in assessing significant lesions were 100%; PPV and NPV were 100%, too; 100% sensitivity and 91.9% specificity for venous grafts; PPV 95.2% and NPV 91.9%. Global sensitivity and specificity of the 64 multidetector was 100% and 98.5%, respectively.Conclusion: 64 slice multidetector computed tomography shows high diagnostic accuracy in coronary artery bypass graft assessment.

C-181 Metabolic syndrome and accelerated atherosclerosis. From clinical data to quantitative arterial involvement: An emerging application of whole body CT angiography A. Napoli, M. Anzidei, B. Cavallo Marincola, C. Zini, P.L. Di Paolo, K. Lanciotti, C. Catalano, R. Passariello; Rome/IT (alessandro.napoli@uniroma1.it)

Purpose: To evaluate location, extent and severity of arterial involvement using 64-detector row CT Angiography (64CTA) and Framingham risk index (FRI) in patients with Metabolic Syndrome (MetS).Methods and Materials: 243 consecutive patients with MetS underwent whole-body 64CTA. Two image data sets were acquired using a 64x0.6 mm detector configuration with an adapted contrast [400 mgI/mL] injection protocol. ECG-gated coronary scanning was performed first, followed by an ultra-low dose (80 kVp) scan

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of the entire arterial system. Coronary and extra-coronary arteries were divided into 15 and 32 segments, respectively. Images were assessed for vascular pathology (normal; moderate or severe stenosis; occlusion and aneurysm). FRI was correlated to location, extent, and severity of coronary and/or extra-coronary atherosclerotic lesions for each patient.Results: A total of 2916 coronary and 7711 extracoronary arterial segments were evaluated. On a per segment basis, atherosclerotic lesions were observed in 691 (20%) coronary and 1044 (13%) extra-coronary segments. Severe ( 75%) stenosis was assessed in 23 coronary and 50 extracoronary segments. Sensitivity and specificity for detection of severe stenosis was 77% and 95% in 34 patients with selective coronary angiography data. Patients categorized as mild-risk ( 10; 20%) according to FRI presented similar extent (p=0.93) of arterial involvement

and location (p=0.48) as those at high-risk. There was a modest, significant re-lationship between severe stenosis as depicted by 64CTA and high-risk indices (r=0.35, P=0.002).Conclusion: 64CTA is a non-invasive modality for imaging atherosclerosis in both coronary and extracoronary arteries. The early detection of atherosclerotic disease in patients with mild cardiovascular risk has potential for preventive therapy.

C-182 Clinical impact of whole body computed tomography angiography (WB-CTA) in patients with suspected coronary artery disease: Incremental value of total atherosclerosis burden assessment A. Napoli, M. Anzidei, B. Cavallo Marincola, C. Zini, P.L. Di Paolo, K. Lanciotti, C. Catalano, R. Passariello; Rome/IT (alessandro.napoli@uniroma1.it)

Purpose: To detect total atherosclerotic vascular burden using a 64-WBCTA pro-tocol based on combined imaging of coronary and systemic arteries.Methods and Materials: 52 patients with coronary artery disease underwent WBCTA for the evaluation of the entire arterial system. Two image data sets were acquired using a 64x0.6 mm detector configuration with an adapted [400 mgI/mL] injection protocol. Coronary artery and whole body arterial districts were divided into 16 and 32 segments, respectively. Coronary angiography (QCA) performed within 20 days was the reference standard for determination of diagnostic performance. Detection of significant ( 50%) coronary stenosis was assessed per-artery, per-segment and per-patient. Coronary arteries were classified as having significant disease ( 50% diameter reduction) or no significant disease ( 50%). Images were assessed independently by two readers.Results: Overall 161/780 (20%) segments had stenosis. The sensitivity and specific-ity of coronary CTA for the detection of significant disease was 78% (125/161) and 94% (584/619) by segment and 90% (62/69) and 93% (81/87) by artery relative to QCA. On a per-patient basis the sensitivity and specificity values were 97% and 82%, respectively. Of 32 patients with multi-coronary involvement, 22 (70%) presented coexisting asymptomatic extra-coronary lesions of whom 9 (28%) had severe segmental arterial stenosis ( 75%). Five (30%) of 17 patients with single vessel significant ( 75%) stenosis had multi-segmental sub-clinical extracoronary involvement. Nineteen (24%) patients required further work-up for asymptomatic atherosclerotic lesions depicted at WB-CTA.Conclusion: WB-CTA allows coronary assessment that compares favourably with QCA and provides extra-coronary direct quantification of subclinical lesions. These results support WB-CTA for early atherosclerotic detection and secondary care in this population.

C-183 Cardiac computed tomography in the evaluation of extensive left anterior descending coronary artery vein patch reconstruction: Preliminary findings M. Fusaro1, E. Calderon2, F. Santini2, E. Maffei1, A. Palumbo1, M. Romano3, S. Seitun3, F. Cademartiri4; 1Parma/IT, 2Verona/IT, 3Genova/IT, 4Rotterdam/NL (filippocademartiri@hotmail.com)

Purpose: To investigate the findings at coronary CT in the evaluation of the ana-tomical and functional results of extensive surgical reconstruction of the left anterior descending coronary artery (LAD) by an autologous vein patch, associated with left internal mammary artery grafting onto the patch.Methods and Materials: Between January 1994 and December 2005, 128 patients, 91 male (71%), with a mean age SD of 67 11 years (range, 42 to 84) underwent the above mentioned procedure. One-hundred and twelve of them (87.5%) were in CCS class III or IV, and 104 (81%) had a three-vessel disease. Mean number of anastomoses/patient was 2.8 7. Length of vein patch ranged between 2 and 6 cm. In-hospital and late (cardiac) mortality were 1.5 and 5.5%, respectively. Mean follow-up period was 64 27 months (range, 5 to 137). Actuarial freedom from recur-rent angina at 5 years is 70%. Up to date, 21 (18%) survivors underwent cardiac CT as a non-invasive imaging tool.

Results: Follow-up CT imaging revealed a full patent LAD graft in all evaluated cases and allowed inferences on the mechanical properties of the vein patch in view of its length and degree of redundancy.Conclusion: Extended reconstruction of the LAD coronary artery increases surgi-cal risk but enhances the probability for a complete revascularization with good mid-term results. Cardiac CT provides comprehensive images and in view of its non invasive nature might become the imaging tool of choice to evaluate complex coronary procedures.

C-184 Diagnostic accuracy of 64-slice computed tomography coronary angiography based on “Mayo Clinic” coronary calcium risk score: Per-segment and per-patient analysis F. Cademartiri1, A. Palumbo2, E. Maffei2, M. Fusaro2, A. Aldrovandi2, N.R. Mollet1, A.C. Weustink1, G.P. Krestin1; 1Rotterdam/NL, 2Parma/IT (filippocademartiri@hotmail.com)

Purpose: To investigate the relationship between the “Mayo Clinic” coronary calcium risk score and the distribution of obstructive coronary artery disease as demonstrated by 64-slice CT coronary angiography.Methods and Materials: 200 patients undergoing contrast enhanced (Iomeprol 400, Bracco) 64-slice CT (Sensation 64, Siemens) coronary angiography for suspected coronary artery disease were retrospectively enrolled into five groups with respect to the Agatston calcium score based on the Mayo Clinic risk stratification: group 1 (score 0), group 2 (score 1-10), group 3 (score 11-100), group 4 (score 101-400), group 5 (score 401). Diagnostic accuracy for the detection of significant ( 50% lumen reduction) coronary artery stenosis was assessed on a per-segment and per-patient base using quantitative conventional coronary angiography as the gold standard.Results: Across group 1 to group 5, sensitivity was 97%, 96%, 91%, 90%, 92%, and specificity was 99%, 98%, 96%, 88%, 90%, respectively, on a per segment basis. On a per-patient basis the best diagnostic performance was obtained in group 1 (sensitivity 100% and specificity 100%) and group 5 (sensitivity 95% and specificity 100%). Progressively higher coronary calcium affects diagnostic accuracy of CT coronary angiography decreasing sensitivity and specificity on a per-segment base. On a per-patient base the best results in terms of diagnostic accuracy are obtained in the populations with very low and very high cardiovascular risks.Conclusion: Diagnostic accuracy of 64-slice CT in the detection of significant CAD is higher with very low and very high calcium burden.

C-185 Detection of significant coronary artery stenosis on a per-patient but not on a per-vessel or per-segment basis in 64-slice CT angiography J.M. Kerl1, C. Herzog1, P. Zwerner2, S. Bisdas1, T. Vogl1, G. Savino2, U.J. Schoepf2; 1Frankfurt a. Main/DE, 2Charleston, SC/US

Purpose: To evaluate 64-slice CT coronary angiography for its diagnostic accuracy for significant stenosis on a global and segmental level in an unselected group of patients and with conventional coronary angiography serving as the reference standard.Methods and Materials: 105 patients with suspected CAD underwent conven-tional coronary catheter angiography and contrast enhanced, retrospectively ECG-gated 64-slice MDCT of the coronary arteries. Two experienced observers analyzed all MDCT-scans for signs of CAD (stenosis=0%; 50%; 70%; 99%; 100%). Diagnostic accuracy compared to cardiac catheter was determined on a per-segment, per-vessel and per-patient basis. No patients, vessels or segments were excluded from analysis.Results: All CT coronary angiograms were considered of diagnostic quality. On a per-segment basis, 92.6% of all segments could be clearly evaluated. In 7.8% of segments, image quality was compromised either by misregistration (15.3%), motion artefacts (34.5%) or small vessel size (49.6%). The correlation coefficients for the detection and grading of stenosis were r=0.67 on a per-segment, r=0.84 on a per-vessel and r=0.89 on a per-patient basis. Stenoses 50% were detected with 96.2% accuracy, 87.5% sensitivity and 96.3% specificity on a per-segment, 96.2% accuracy, 94.3 % sensitivity and 97.8% specificity on a per-vessel, and 99.0% accuracy 100% sensitivity and 98.4% specificity on a per-patient basis. Stenoses 70% were detected with higher accuracy than stenoses 50% without reaching

statistical significance (p=0.75).Conclusion: 64-slice MDCT coronary angiography allows for reliable diagnosis of significant CAD on a per patient basis. On a per-segment and per-vessel basis, diagnostic accuracy is still impaired, primarily by limited spatial resolution.

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C-186 Accuracy of dual-source computed tomography in the assessment of plaque morphology: Use of quantitative plaque analysis software in comparison with IVUS virtual histology H. Brodoefel1, C. Burgstahler2, M. Heuschmid2, I. Tsiflikas2, A. Reimann2, A. Kopp2, S. Schroeder2, C.D. Claussen2, M. Clouse1; 1Boston, MA/US, 2Tuebingen/DE (hbrodofe@bidmc.harvard.edu)

Purpose: To assess Dual-Source computed tomography (DSCT) and a Hounds-field unit (HU)-based analysis approach in the classification and quantification of atheroma.Methods and Materials: DSCT and intravascular ultrasound (IVUS) virtual histol-ogy (VH) were prospectively performed in 13 patients and 20 lesions were compared in terms of maximal percent vessel stenosis and volumes of vessel, lumen, plaque or fatty, fibrous and calcified components. Volumes were compared between visual adjustment of HU-based colour maps to plaque components as well as use of pre-set HU cut-offs or optimized thresholds that were obtained through de-blinded manual calibration of plaque volumes in DSCT to IVUS-VH.Results: Percent vessel stenosis in DSCT (49 12%) and IVUS (51 14) were closely correlated (r2=0.71). Mean IVUS-VH correlated HU-ranges for fatty or fibrous plaque, lumen and calcified lesions were -6-66, 67-153, 154-446 and 447+. Using these HU cut-offs, DSCT showed moderate or good correlation with IVUS-VH regarding volumes of lumen (r2=0.80), plaque (r2=0.72) and fatty (r2=0.63), fibrous (r2=0.61) or calcified components (r2=0.35). Corresponding R-squared values for pre-set HU-thresholds (0-70, 71-130, 131-400, 400+) and visual adjustment of colour maps were 0.65, 0.47, 0.51, 0.56 and 0.07 or 0.77, 0.64, 0.48, 0.53 and 0.63. Systematic underestimation was observed for use of pre-set HU-ranges and fibrous plaque; overestimation was noted for visual assessment of non-calcified plaque (P 0.01). Prospective HU based plaque analysis showed good reproduc-ibility with intra-class-correlation-coefficients for vessel, plaque and fatty, fibrous or calcified components being 0.96, 0.94, 0.85, 0.97 and 1.00.Conclusion: Prospective HU-based analysis software allows for accurate and reproducible characterization of non-calcified plaque.

C-187 Diagnostic accuracy of 64-slice computed tomography in quantification of coronary artery stenosis: Comparison with intravascular ultrasound J. Hur, B. Choi, Y. Kim, H.-J. Lee, D. Choi, K. Choe; Seoul/KR (khuhz@yuhs.ac)

Purpose: The aim of our study was to determine the diagnostic accuracy of cardiac 64-slice MDCT in quantification of coronary artery stenosis in comparison with intravascular ultrasound (IVUS).Methods and Materials: Thirty-two patients (43 sites) who were diagnosed as hav-ing significant coronary artery stenosis, and underwent both cardiac CT and IVUS, were selected. For each stenotic site, the maximum external elastic membrane cross-sectional area (EEM CSA), the maximum lumen CSA, the maximum plaque area, as well as the maximum percentage of luminal obstruction was measured. The results measured by cardiac CT were compared with those obtained by IVUS using paired-t test. Correlations of the measurements between cardiac CT and IVUS were performed using Pearson’s correlation coefficient. P-values less than 0.05 were considered statistically significant.Results: The mean EEM areas, the mean lumen areas, the mean plaque areas and the percentage of vessel obstruction measured by cardiac CT and IVUS were 14.6 4.3 mm2 versus 15.9 6.4 mm2 (p 0.01), 3.7 1.7 mm2 versus 3.2 2.6 mm2 (p 0.01), 10.9 3.5 mm2 versus 12.7 5.4 mm2 (p 0.01), and 72.3 8.6% versus 79.6 10.2% (p 0.01). The correlation coefficients for these measurements were r=0.738, r=0.788, r=0.765, and r=0.794, respectively.Conclusion: Cardiac 64-slice CT is a noninvasive modality that allows quantification of coronary artery stenosis. Measurements of percentage of luminal obstruction, plaque and lumen areas derived by CT correlated well with IVUS.

C-188 The role of color identification for coronary plaque imaging in interpretation of gray scale coronary MDCT S. Choi1, Y. Kim1, H. Seon1, Y. Choi1, N. Chang2, H. Kang1; 1Kwangju/KR, 2Chollanamdo/KR (songchoi@cnuh.com)

Purpose: To evaluate the role of color identification (CI) according to CT number for coronary plaque imaging in the interpretation of gray scale coronary CT image.Methods and Materials: 111 coronary segments of 60 patients with atypical chest pain who underwent coronary MDCT with CI were evaluated in this study. Source images obtained with 64-channel MDCT were transferred to workstation, and then curved multiplanar reformation (MPR) images of major coronary artery (LAD, LCX

and RCA) were reconstructed. CI display according to CT number (0~60 H.U: blue, 61~150 H.U: yellow, 151~600 H.U: green, 601 H.U: red) was performed with overlapping on gray scale curved MPR images. Image analysis was performed by two radiologists with consensus to plaque nature and degree of luminal narrowing on both CI and gray scale MPR image, respectively. Plaque nature was classified into 4 groups as none/soft/mixed/calcified nature. Luminal narrowing was graded into 3 groups as 0%, 50% and 50%. Wilcoxon signed ranks test was used for statistical analysis of agreement.Results: In the evaluation of plaque nature, the overall agreement between CI with gray scale curved MPR image was 44% (p 0.05). We had 62 (66%) cases of disagreement between CI and gray scale MPR image. Soft plaque was underes-timated at CI in 41 segments. In the assessment of luminal narrowing, the overall between CI with gray scale curved MPR image was 56.7% (p 0.05).Conclusion: CI appears to be a supplementary display tool with gray scale curved MPR image in the evaluation of coronary plaque.

C-189 Evaluation of atrial septal aneurysms with ECG-gated multi-slice computed tomography E. Czekajska-Chehab, M. Tomaszewska, E. Siek, A. Tomaszewski, G. Staskiewicz, S. Uhlig, A. Drop; Lublin/PL (uhlig.s@eranet.pl)

Purpose: Atrial septal aneurysm (ASA) is an uncommon cardiac anomaly with protrusion of interatrtial septum (IAS) into the left or right atrium or both in the anatomical location of ostium primum. It is suggested that ASA is a potential risk factor for cardioembolism and arrhythmias. ASA may be isolated malformation, but often is associated with other cardiac anomalies: patent foramen ovale or mitral valve prolapse. At present, echocardiography is essential for the diagnosis of this anomaly. The aim of the study was to present feasibility of ECG-gated multi-slice computed tomography (MSCT) in imaging of ASA.Methods and Materials: We analyzed the ECG-gated MSCT examinations of the heart performed in 1758 patients between 2002 and 2007 and compared the results with clinical data and echocardiography. ECG-gated MSCT examinations were per-formed with 8- and 64-row scanners. Morphology of ASA, amplitude of phasic excur-sion of IAS during the cardiac cycle and associated anomalies were analyzed.Results: ASAs were detected in 31 patients (1.76%). In all cases, ASA was localized in the typical place - ostium primum. In 29 cases, IAS protruded into the right atrium and in 21 patients, the protrusion increased in the end-diastolic phase. The mean diameter of aneurysmatic portion was 26.5 1.3 mm. Patent foramen ovale was found in 5 cases, tricuspid insufficiency in 3 and ventricular septal defect in 1. In all cases, echocardiography was found to be in complete concordance with MSCT.Conclusion: EGG-gated MSCT of the heart is a very valuable method in the diagnosis of ASA and associated anomalies.

C-190 Detection and assessment of intracardiac thrombi with multi-slice computed tomography (MSCT) E. Czekajska-Chehab, E. Siek, G.J. Staskiewicz, S. Uhlig, A. Tomaszewski, A. Wysokinski, A. Drop; Lublin/PL

Purpose: Intracardiac thrombi may form in the course of multiple conditions: ischemic heart disease, cardiomyopathy, endocarditis, atrial fibrillation, implanta-tion of pacemakers, and others. Formation of thrombus may result with serious consequences, including stroke or mesenteric embolism when thrombi are located in left heart, or pulmonary embolism when located in the right heart. The aim of the study was to assess feasibility of MSCT for detection of intracardiac thrombi, to analyze location, size, density and mobility of thrombi in particular chambers of heart. Results were compared with echocardiography.Methods and Materials: We retrospectively analyzed 1914 ecg-gated-MSCT and 300 angio-CT examinations of heart, performed between 2003 and 2007. The examinations were performed with 8-row and 64-row scanners.Results: Intracardiac thrombi were found in 43 patients (1.94%), most commonly in patients with ischemic heart disease (17 cases), permanent pacing (9 cases), acquired heart defect (6 cases) and cardiomyopathy (5 cases). Thrombi were localized in left ventricle in 16 cases (32%), in left atrium in 14 cases (27%), right atrium in 13 (25%) and right ventricle in 8 cases (16%). The largest thrombi were found in left atrium (mean volume 34 72 cm3) and left ventricle (20 29 cm3). In 11 patients (25.6%), mobility of thrombus was visualized. Attenuation of thrombi ranged from 12 to 150 HU. Cardio-CT examinations visualized more intracardiac thrombi as compared with echocardiography.Conclusion: MSCT is a valuable method of assessment of the intracardiac thrombi. Thrombi are present in almost 2% of cardio-CT examinations. The largest thrombi were visualized in chambers of the left heart. No Material Submitted to EPOS

No Material Submitted to EPOS

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C-191 Coronary artery anomalies J. Alex1, K.T. Tan2, M.C.K. Hamilton2, P. Wilde2, G.M. McGann2; 1Cheltenham/UK, 2Bristol/UK (jtealex@gmail.com)

Learning Objectives: To enable to reader to understand: (1) coronary artery abnormalities that are encountered on CT or MRI; and (2) the clinical relevance of these abnormalities.Background: The growth of CT and MRI has resulted in the enhanced detection of many types of coronary artery abnormalities. The commonest of these is coronary atherosclerosis. However, there are many other types of clinically relevant coronary artery anomalies that can be detected on CT/MRI. These include anomalous coro-nary origin, myocardial bridging or intramyocardial course of the coronary vessel, coronary artery fistula, and coronary aneurysms. It is important that the radiologist is able to recognise these anomalies are often incidental findings on a scan done for a completely different reason.Procedure Details: This abstract reviews the CT/MRI features and clinical relevance of: (1) anomalous coronary origin; (2) coronary artery fistula; (3) coronary aneurysms; (4) myocardial bridging; and (5) intramyocardial course of the coronary vessel.Conclusion: CT/MRI is extremely useful in the detection and characterisation of coronary anomalies. Many of these anomalies are clinically relevant and should not be ignored on the final report.

C-192 The myocardial perfusion imaging finding of transient ischaemic dilatation: A pictorial review N. Kakouros, V. Raman, S. Adhya, K. Foord; Hastings/UK (nkakouros@gmail.com)

Learning Objectives: Transient Ischaemic Dilatation (TID) of the left ventricle on myocardial perfusion imaging is an important image finding with significant clini-cal and prognostic implications. It has a complex aetiology and can be seen in a number of conditions. We describe the different pathophysiological mechanisms that have been implicated in this phenomenon, the resulting image findings and their clinical implications.Background: During SPECT perfusion imaging, the endocardial surface is es-timated using edge detection algorithms and can therefore be used to compare ventricular cavity sizes during rest and stress. The apparent dilatation of the left ventricle during stress on myocardial perfusion imaging has been termed TID and is considered a marker of severe coronary artery disease with poor prognosis. This image finding, however, does not always correlate with epicardial vessel stenosis and can occur in a number of other non-ischaemic pathologies.Imaging Findings: We describe pictorially the methods for detection of TID and the subtle differences that can help differentiate between ischaemic and non-ischaemic aetiologies, providing examples.Conclusion: TID is an important myocardial perfusion study finding, which can occur in conditions other than severe coronary artery disease. Accurate evalua-tion and interpretation of this finding is important from a clinical and prognostic perspective.

C-193 Fat in the heart: Causes and meaning G. Tardaguila de la Fuente, F. Tardaguila, J.A. Aguilar, R. Prada, D. Castellon, G. Fernandez; Vigo/ES (gonzatar@hotmail.com)

Learning Objectives: 1.To describe the conditions where fat could be found by CT and MRI studies in heart lesions. 2.To illustrate that fat detection in heart lesions is useful for narrowing the differential diagnosis.Background: Fat detection is always a useful clue to the radiologist. Any lesion at any location with fat inside it will help radiologists to make shorter and more precise differential diagnosis. The heart is not an exception. Until now, cardiac fat had a low impact on radiological literature. This is probably a consequence of the low sensitivity of conventional radiology for fat detection. The development of cardiac CT and MRI makes possible the identification of fat in heart lesions and now it is time for radiologists to know their meaning.Imaging Findings: We present different conditions and locations where fat could be found in the heart with cardiac CT or MR. We illustrate fat accumulation in normal anatomic structures simulating diseases, such as lipomatous hypertrophy of the atrial septum, crista terminalis, pericardium, etc. We also illustrate myocardic pathologies

containing fat-like arrythmogenic right ventricular dysplasia and the uncommon form involving the left ventricular wall, chronic myocardial infarction, fat associated with hypertrophic cardiomyopathy and intramyocardic lipomas. Finally, fat can also be found in coronary arteries as a sign of high risk atherosclerotic plaque.Conclusion: 1.The number of heart lesions with fat inside is limited. 2.Fat detection narrows the differential diagnosis. 3.Fat deposits sometimes are a normal variant and do not require treatment. 4.Fat in atherosclerotic plaques suggests a high risk, which could mean treatment independent of the grade of stenosis.

C-194 Getting to the heart of the matter: An illustrative look at cardiomyopathies S.R. Harris, A. Misselt, P.A. Araoz, E. Williamson; Rochester, MN/US (harris.scott@mayo.edu)

Learning Objectives: To illustrate the spectrum of cardiomyopathies and their MR imaging patterns; to describe various MR imaging techniques and those that are unique to certain disease processes; to illustrate MRI delayed enhancement patterns of various cardiomyopathies.Background: Cardiomyopathies are a diverse collection of diseases, most com-monly imaged using MRI. Discrimination between diseases is essential as the prognosis and treatment differ for each. While there is significant overlap in ap-pearances between cardiomyopathies, careful examination of the morphology and delayed enhancement pattern can direct the diagnosis.Imaging Findings: Hypertrophic cardiomyopathy, the most common cardio-myopathy, has a distinct set of imaging findings: hyperdynamic function, septal hypertrophy and outflow tract obstruction. On delayed contrast-enhanced imag-ing, hyper-enhancement of the hypertrophied myocardium and right ventricular insertion points is characteristic. In contrast, amyloidosis demonstrates restric-tive function, hypertrophy of the ventricular walls, valvular and atrial thickening and potential pericardial effusions. On delayed contrast-enhanced imaging, amyloidosis may demonstrate results ranging from diffuse, patchy myocardial enhancement to a distinctive subendocardial pattern. Dilated cardiomyopathy demonstrates an enlarged left ventricle and decreased systolic function. Delayed contrast-enhanced imaging may demonstrate a characteristic mid-myocardial stripe. Myocarditis may not demonstrate any abnormalities prior to the admin-istration of contrast. Patchy, delayed enhancement of the inferior and lateral free wall is diagnostic of myocarditis in the appropriate clinical setting. Iron-overload cardiomyopathy is not frequently encountered. When the diagnosis is considered, however, T2* mapping of the myocardium is vital to ascertain the correct diagnosis.Conclusion: MR morphologic findings and characteristic delayed enhanced images allow in the distinction between various cardiomyopathies.

C-195 Imaging of fetal coronary arteries with gray and color flow Doppler sonography E.-K. Ji, T. Kwon, S. Kang, D. Kim; Seoul/KR (jiekkorea@hanmail.net)

Learning Objectives: 1. To investigate coronary arteries in non-IUGR fetuses in the second trimester. 2. To propose a method to demonstrate normal fetal coronary arteries on gray and color Doppler sonography.Background: Previous studies have shown that while coronary blood flow may be readily visualized in the third trimester, earlier visualization, or sudden ability to visualize coronary blood flow, can occur in certain clinical conditions such as fetal growth restriction or fetal anemia. However, advances in ultrasound technology lowers the visualization threshold for coronary arteries.Procedure Details: Between 20 and 28 gestational weeks, well-selected, non-IUGR fetuses were included. Sonographic studies started on the short axis view of the heart at the aortic valve level, because the recognition of the right and the left coronary cusp was essential to find the ostia of each coronary artery. After determining each ostium, a tilt of the probe along the right atrioventricular groove revealed the right coronary artery, and the left coronary artery was seen just behind the pulmonary trunk.Conclusion: Fetal coronary arteries could be seen in almost all of the normal fetuses in the second trimester. Short axis view of the heart, with identification of each coronary cusp, was the first step in the study of coronary arteries.

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C-196 Unusual cardiac metastases in oncologic patients: A pictorial review E. Salvador, A. Martínez, M.S. Gallego, E. Zabia; Madrid/ES (elenasalvadoralvarez@hotmail.com)

Learning Objectives: To describe the development of cardiac metastases arising from uncommon tumors and to illustrate the imaging findings of various histological types of these metastases on MDCT.Background: Cardiac metastases are more frequent than primary cardiac tumors. In patients with cardiac metastases, pericardium and epicardium are most commonly involved, unlike myocardial metastases, which are far less frequent. The most common tumoral sources are cancers of the lung and breast, melanoma and lymphoma. We ret-rospectively reviewed cases that were attended in our institution in the last 5 years.Procedure Details: Cardiac metastases are compiled from CT studies used for the evaluation and follow-up of oncological patients. Those cases that originated from tumors traditionally known, like cardiac metastases producers, were excluded. Various examples of these unusual metastases are shown, affecting different parts of the heart in each case, as well as their appearance on MDCT and, in some of the cases, their progression on CT.Conclusion: Due to the increase in the survival of oncologic patients and the use of MDCT for their evaluation and follow-up, cardiac metastases are more frequently diagnosed as an incidental finding, and among these, those arising from tumors not previously described. The radiologist should take into account the oncologic history of the patient when confronted to a cardiac mass, in order to make a proper differential diagnosis”.

C-197 Where is the wire? A review of cardiological wires and devices M. Metelko, R. Summerfield, M. Goldstein, D.P. Deva, H. Sandmann; Stoke on Trent/UK (mmetelko@hotmail.com)

Learning Objectives: To understand the use of pacemakers and implantable devices, their optimal location and the relevant physiology and anatomy. To give a brief overview of complications of devices as assessed radiologically.Background: Before commenting on satisfactory lead placement on a film with a pacemaker, the radiologist should first be able to identify where the lead, or leads, must be ideally situated. It is only after the radiologist understands this that he will be able to comment on the correct placement or not of leads, and if not, where the leads are located then. By being familiar with different pacemaker types, the radiologist can understand the implications of device failure. Changing practice in cardiology has resulted in new implantable devices, smaller than ever, which may not be recognised as such, as well as the development of more complicated pacing patterns.Imaging Findings: Images of correctly placed single, dual and triple chamber pacing leads will be reviewed, as well as epicardial pacing leads, the commonest pacemakers and implantable devices. Further to this, images of fractured leads, displaced leads and other device failures will be evaluated, alongside soft tissue complications such as thrombosis and infections.Conclusion: It is important for radiologists to have an understanding of the anatomy and physiology of the cardiac cycle as it is necessary in assessing correct lead placement for pacemakers and other implantable devices. Problems with leads are rare and easily detectable on plain film and recognising these can ultimately help to avoid potentially fatal complications.

C-198 Atrial fibrillation: Imaging guidance of ablation therapy with CT C.W. Lott; Adelaide/AU

Learning Objectives: 1. Develop basic understanding of the atrial anatomy. 2. Understand the current state of ablation therapy for atrial fibrillation. 3. Become aware of the integration of imaging and intervention in cardiac ablation therapy.Background: Electrophysiological mapping and percutaneous catheter-guided ablation are well-established therapies for cardiac arrhythmias due to conduction anomalies. Atrial fibrillation (AF) is the most frequently occurring supraventricular tachyarrhythmia and chronic atrial fibrillation and warfarin treatment have risks. AF may be initiated by ectopic beats originating from the ostia of the pulmonary veins. Isolation or ablation of these foci has become an established, but evolving, method of treating atrial fibrillation.

Procedure Details: Preoperative ECG-gated multi-detector CT angiography is used in our institution to image the pulmonary veins and left atrium, to measure the ostial sizes, morphology of the vessels, rule out thrombus in the atrial appendage and rule out developmental anomalies. The DICOM data set is used to produce a 3D map for “virtual” navigation. Follow-up CT at 12 months is used to rule out pulmonary vein stenosis.Conclusion: Imaging by CT is becoming integral in AF treatment.

C-199 Follow-up chest X-rays after CABGs: A waste of time and money S. Karthik, D.J. O’Regan; Leeds/UK (suchkats@yahoo.com)

Purpose: Chest X-ray is part of routine practice in the follow-up of Coronary Artery Bypass Graft (CABG) patients. Their value was questioned, audited and re-audited following a change of practice.Methods and Materials: 666 CABG patients were identified from the Patient Analysis and Tracking System database representing the work of a single surgeon between 07/02/01 and 30/09/05. The data regarding clinical and radiological findings were collected from the follow-up clinic letters and case notes. Following a change of practice, we re-audited the impact of not performing routine chest X-rays on 132 patients between 01/03/2006 and 28/12/2007.Results: 11 patients died and 10 either refused or failed to arrive for follow-up. 682 chest X-rays were done in 645 patients. 13 patients (2%) were found to have a pleural effusion on chest X-ray. This was confirmed on clinical examination in seven patients (53.9%). One patient needed re-admission and intervention. Seven patients were discharged and the other five were followed up with repeat chest X-rays before discharge. Following this, we changed our practice and performed X-rays only when indicated. Chest X-ray was performed in 5 out of the 132 patients, all for pleural effusion. Two of these patients needed drainage. This has resulted in a savings of £3200.Conclusion: The yield of routine chest X-ray in CABG follow-up clinic is low (2%) and the need for intervention is rare. A re-audit after change of practice has further demonstrated that clinically directed chest X-rays are cost-effective, safe and help stream-lining the outpatients department.

C-200 Integrating CT in minimally invasive treatment of the coronary arteries D. Ruijters1, N.H. Bakker1, O. Wink1, B.M. ter Haar Romeny2, P. Suetens3; 1Best/NL, 2Eindhoven/NL, 3Leuven/BE (danny.ruijters@philips.com)

Purpose: A novel method for the integration of cardiac CT in X-ray fluoroscopy procedures, enabling better decision making in the planning and guidance of cardiovascular interventional therapies.Methods and Materials: Our method offers the possibility of determining the C-arm incidence with the least foreshortening for a selected segment of the coronary vessels, segmented in a pre-operative cardiac CT dataset. In order to assist in stent length selection, the length of a vascular lesion can be measured in 3D along the centerline of the curved vessel. During the intervention the stored C-arm incidence can be recalled, and the C-arm can be automatically steered to the appropriate angles. Furthermore our method allows rendering of a curved MPR and a 3D volume of the coronary arteries, both following in real-time the direction of the viewing incidence of the C-arm. Based on this automatically registered reference image of the CT data, it is possible to steer the C-arm, without using additional contrast medium or X-ray radiation.Results: The proposed method has been applied in the treatment of 20 patients. The 3D visualization of the coronary arteries, segmented in the CT dataset, aug-ment the sense of orientation and enhance navigation, especially when no contrast medium is visible in the fluoroscopy images.Conclusion: The integration of cardiac CT data helps in improving planning and guidance of cardiovascular interventional therapies. The optimal system angles from true 3D datasets enable better stent length selection and in addition can lead to a reduction in the use of contrast medium.

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C-201 Radiologic staging of primary lung cancer: Questions and answers B. Graca, L. Semedo, M. Seco, A. Canelas, L. Teixeira, F. Caseiro-Alves; Coimbra/PT (brunomiguel@inbox.com)

Learning Objectives: Providing an educational and pictorial review of radiologic staging of primary lung cancer.Background: In patients with lung cancer, the anatomic extent of the tumour is crucial for the determination of which therapeutic approach to choose. The main objective of radiologic preoperative staging is to select patients with localised disease who may benefit from surgery, while avoiding unnecessary thoracotomies in patients with unresectable neoplasm. Imaging studies may also evaluate if the unresectable tumour can be encompassed within a tolerable radiation therapy port. Computed tomography (CT) of the chest is the principal method for staging local and regional spread of lung neoplasms. Mediastinoscopy, magnetic resonance imaging (MRI) and positron emission tomography (PET) have specific roles and complement the evaluation of these patients.Procedure Details: Through case illustration and presenting the text in the question-and-answer format, we will discuss the relevant aspects for accurate staging of primary lung cancer, following the TMN international staging system. Particular attention will be given to the assessment of lymph node, chest wall and mediastinal invasion. The complementary role of mediastinoscopy, MRI and PET will be discussed.Conclusion: Adequate preoperative staging of lung cancer provided by imaging studies affect the therapeutic management and outcome of patients.

C-202 High-resolution computed tomography in adult patients with cystic fibrosis: Findings and scoring B. Graca, J.F. Costa, A. Canelas, F. Gamboa, L. Teixeira, F. Caseiro-Alves; Coimbra/PT (brunomiguel@inbox.com)

Learning Objectives: Providing an educational and pictorial review of the HRCT imaging features of cystic fibrosis (CF) in adult patients. Illustrating the modified Bhalla CT scoring system for HRCT abnormalities described in CF lung disease and discussing its relevance in the follow-up of these patients.Background: Although there has been an improved survival of CF patients, this condition is still the most frequently inherited disorder leading to premature death in the Caucasian population. Pulmonary dysfunction causes major morbidity in CF, and more than 90% of the mortality is caused by pulmonary complications. It is therefore critically important to monitor progression of lung disease for clinical treat-ment and to evaluate new treatments. HRCT imaging features and corresponding scoring systems demonstrated in recent studies to be a useful outcome measure surrogate in patients with cystic fibrosis.Procedure Details: The presentation will be organized in 3 parts. In the first part, we will review the HRCT imaging features of CF lung disease, followed in the second part by the presentation and illustration of the modified Bhalla CT scoring system. We conclude our work discussing current investigation about the applicability and clinical importance of HRCT and corresponding scoring system in the follow-up of adult patients with CF.Conclusion: Structural abnormalities observed on HRCT scans of adult patients with CF lung disease can be assigned with currently available scoring systems, which proved useful to monitor progression of disease and influence both patient treatment and therapeutic studies.

C-203 Imaging appearances of adult congenital lung diseases: A pictorial review E.T.D. Hoey, P. Bhatnagar, K. Mankad, M. Darby, R. Robertson; Leeds/UK

Learning Objectives: To highlight the spectrum of imaging findings of congenital lung diseases presenting in adulthood. To understand the modes of presentations and potential complications of these conditions. To develop a wider perspective in approaching the differential diagnoses of adult thoracic pathology.Background: Congenital lung anomalies are often detected for the first time in adult-hood when they can simulate and mimic a wide range of adult thoracic pathologies including life-threatening infections and neoplastic conditions; thus the potential for grave misdiagnoses. While some of these conditions are simply incidental findings requiring no specific management, others can be potentially life threatening and must be managed appropriately.

Imaging Findings: We present a pictorial review covering the clinical and radiologi-cal spectrum of congenital lung diseases including tracheo-bronchial anomalies, bronchopulmonary sequestration, cystic adenomatoid malformation and hypoge-netic lung syndrome. A selection of plain film and cross-sectional images using computed tomography and MRI provide clear examples of these not-to-miss condi-tions. A case of each entity is presented with an emphasis on the contemporary approach to diagnostic investigations.Conclusion: The recognition of congenital lung disease in adults is of paramount importance. Knowledge of the range of radiological appearances will help avoid potential diagnostic mistakes and direct correct and timely patient management.

C-204 Cystic fibrosis: A compendium of HRCT findings I.P. Gunatunga, R. Gadahadh, S. Singh, M. Crane, H. Adams; Cardiff/UK (ishangune@gmail.com)

Learning Objectives: 1. To illustrate the spectrum of high resolution CT findings seen in cystic fibrosis; 2. To classify these findings in terms pathophysiology and chronology in the disease process; and 3. To assess the implications and benefits of early treatment on disease progression.Background: Cystic fibrosis (CF) is the most common lethal inherited disease in persons of European origin. It is an autosomal recessive disorder, and most carriers of the gene are asymptomatic. Pulmonary involvement occurs in 90% of patients. End-stage lung disease is the principal cause of death. We will review the multitude of HRCT findings that evolve in patients with CF and classify these in terms of likely chronology and their implications for treatment and the patients’ life expectancy.Imaging Findings: Our aim is to review the pathophysiology and the multitude of HRCT findings that evolve in patients with cystic fibrosis in the lungs. We also discuss the likely chronology of these imaging findings in the course of the disease and its implications for treatment.Conclusion: Patients with cystic fibrosis demonstrate a myriad of HRCT features. Some of these can be quite specific for this condition, while others can be seen in other chronic lung pathology. The HRCT findings can influence decisions on treatment and affect patient mortality.

C-205 Pictorial review of CT features of endobronchial lesions P. McParland, R. Ayer, S. Harden, I. Brown, C. Peebles; Southampton/UK (pmcparland2000@hotmail.com)

Learning Objectives: To identify and illustrate typical features of endobronchial lesions on CT.Background: CT plays an important role in the identification and characterisation of endobronchial lesions. The typical appearances of some lesions allow confident diagnosis on CT. Adverse features may be identified and guide bronchoscopic resection or thoracotomy. Here we discuss and illustrate CT features of common endobronchial lesions.Imaging Findings: Benign endobronchial lesions with characteristic CT features are endobronchial lipomas and hamartomas. Lipomas are central and typically fat attenuation while hamartomas are smooth lobulated structures with popcorn calcifica-tion. Other benign lesions are mucin producing adenomas. These present as a filling defect surrounded by mucus and this is compared to a sputum cast. Endobronchial sarcoid can appear as a constricting lesion on bronchoscopy. Primary bronchogenic carcinomas are the most common endobronchial lesions. Malignant features of the tumour may be identified on CT. We present cases of endotracheal bronchogenic carcinoma and a destructive carcinoma eroding the bronchial wall. Other malignant lesions are endobronchial carcinoid. These are typically hyperdense endobronchial mass lesion and less commonly hypodense pedunculated lesion.Conclusion: Mulislice CT is a powerful tool in the diagnosis of endobroncial lesions; a good understanding of characteristic CT features may indicate the histolgical diagnosis and guide appropriate intervention.

C-206 Ground-glass opacification: Is it possible to achieve a specific diagnosis based on radiological and clinical features? C. Vázquez Olmos, M. Rodríguez Rodríguez, A. Sánchez González, J. Plasencia Martínez, C. Ordoñez González, C. Ortiz Morales; Murcia/ES (ca.olmos@yahoo.es)

Learning Objectives: To illustrate the diseases that present ground-glass opacifi-cation of the lung on CT and high-resolution CT. To emphasize clinical information and radiological findings that are helpful in narrowing the differential diagnosis or even suggesting a specific diagnosis.

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Background: Ground-glass opacities (GGO) are defined as focal or diffuse areas of ill-defined, hazy, increased attenuation of the lung, with preservation of bronchial and vascular margins. They can represent either interstitial or alveolar processes and are a common manifestation of multiple pulmonary diseases. A better diagnostic approach is possible if features of the underlying disease are identified, such as the duration of clinical symptoms, distribution of the opacification, history of smoking and presence or absence of fibrosis.Procedure Details: We present our experience with representative cases of ground-glass pattern in which we were able to suggest a specific diagnosis by means of imaging features and clinical data. We review and illustrate these various patholo-gies that can result in GGO, such as acute processes: the most common being pulmonary edema, infection and hemorrhage, pathologies with chronic symptoms, including interstitial pneumonitis, hypersensivity pneumonitis, smoking-related lung disease, alveolar proteinosis and neoplastic disorders.Conclusion: GGO are non-specific findings caused by a wide group of diseases. Radiologists should approach these processes by correlating the clinical history with the CT distribution of the disease and any associated abnormalities. This can help lead to a correct diagnosis or, at least, narrow the range of possibilities.

C-207 Pictorial review of imaging appearances of bronchioalveolar cell carcinoma (BACC) P. McParland, N. Railton, C. Peebles, I. Brown, S. Harden; Southampton/UK (pmcparland2000@hotmail.com)

Learning Objectives: To illustrate the different imaging properties of BACC.Background: BACC accounts for less than 5% of all bronchogenic carcinomas. Unlike other histological lung cancer types, however, its incidence is increasing, particularly in younger, non-smoking women. It typically takes an indolent clinical course and diagnosis is often made at an advanced stage. A small subset of patients develop bilateral consolidation and die within months. The diagnosis is often made at post mortem. The plain radiograph and CT features of BACC are diverse and often mimic benign pathologies; thus an appreciation of the range of radiological appearances is important.Imaging Findings: BACC classically presents as a consolidative mass that spreads using lung structures as stroma. We aim to illustrate a variety of imaging appear-ances of histologically proven BACC, including CT and plain radiograph findings. The illustrated appearances include focal consolidation, a solitary spiculate lesion, a mass replacing a lung lobe, multiple lesions confined to a single lobe, the ‘CT angiogram sign’ and gross crazy paving.Conclusion: As the proportion of new bronchogenic carcinomas proven to be BACC rises in a younger, non-smoking population, it is vital for radiologists and clinicians to be aware of the range of imaging appearances to allow for prompt diagnosis and optimal clinical care.

C-208 Chronic pulmonary embolism: A radiologic overview E. Ballesteros Gomiz1, E. Castañer González1, X. Gallardo Cistare1, J.M. Mata Duaso1, Y. Pallardó Calatayud2, A. Valera Abril1; 1Sabadell/ES, 2Alzira/ES (eva.gomiz@gmail.com)

Learning Objectives: To review the imaging findings that enable chronic throm-boembolic pulmonary disease (CTPD) to be suspected and diagnosed. To discuss the usefulness of multislice CT and updated CT angiographic protocols and their application in routine clinical practice when evaluating patients suspected of having thromboembolic pulmonary hypertension.Background: Symptomatic CTPD occurs after pulmonary embolism more often than was previously thought. Nonspecific symptoms and lack of medical history of previous venous thromboembolism often complicate accurate diagnosis. Imaging is central in diagnosing and managing CTEPD. Multislice CT can also help distinguish CTPD from other forms of pulmonary hypertension.Imaging Findings: We reviewed the CT findings of 22 patients with CTPD and classified them into three groups to facilitate learning: 1) Vascular signs - direct CT signs of chronic embolism (complete/partial occlusion; eccentric thrombi; calcified thrombus; webs, bands, post-stenotic dilatation); CT signs of pulmonary hypertension (collateral systemic supply). 2) Parenchymal signs (mosaic perfusion; parenchymal scarring; bronchial dilation). 3) Cardiac signs. We also discuss the differential diagnoses (acute thromboembolism, congenital anomalies, arteritis, bronchial pathology).Conclusion: Radiologists need to know the signs that raise suspicion of CTPD and enable the diagnosis. Recognition of CTPD can improve patient outcome since this condition is potentially curable by pulmonary endarterectomy.

C-209 High-resolution computed tomography of the chest: What every radiologist should know N. Bharwani, S. Grubnic; London/UK

Learning Objectives: 1. To review the normal anatomy of the secondary pulmonary lobule. 2. To illustrate the basic patterns of disease including interstitial, airway and vascular diseases.Background: High-resolution computed tomography (HRCT) is an essential tool used in the assessment and diagnosis of interstitial lung disease and other dif-fuse lung diseases e.g. bronchiectasis and sarcoidosis. HRCT is more sensitive and specific than chest radiography and provides information on the patterns and distribution of lung processes and plays a significant role in early detection, characterisation, and diagnosis.Imaging Findings: This pictorial review will discuss the applications of HRCT in both chronic and acute lung disease. We will discuss the normal anatomy of the secondary pulmonary lobule and the different parenchymal patterns identified, e.g. mosaic, reticular, tree-in-bud. We illustrate how analysis of the distribution and pat-tern of disease allows the interpreting radiologist to arrive at a diagnosis.Conclusion: HRCT plays an important role in the radiological assessment of intra-thoracic disease. Analysis of the pattern of parenchymal involvement and disease distribution allow formulation of a reasonable differential diagnosis and arrival at an accurate diagnosis.

C-210 Benign or malignant? Pulmonary nodules from a lung cancer screening setting A.L.M. Leusveld, Y.R. Zhao, D.M. Xu, Y. Wang, M. Oudkerk; Groningen/NL (anneleusveld@gmail.com)

Learning Objectives: To demonstrate the practice of evaluating pulmonary nod-ules based on low-dose CT images, and to increase the radiologists’ experience in differentiating benign from malignant nodules.Background: Indeterminate pulmonary nodules pose a dilemma in lung cancer screening trials as well as in a clinical setting. The aim is not to miss any malig-nancies while not unnecessarily subjecting patients to hazardous investigations. Diagnostic features such as size, morphology and Volume Doubling Time (VDT) can help differentiate benign from malignant nodules.Imaging Findings: In pulmonary nodules, a large size and short VDT increase the chance of malignancy. Regarding morphology, non-solid and ground-glass attenuation, and a spiculated margin in solid nodules are also features associated with malignancy. Calcification and intranodular fat are indicative of a benign nature. We present cases from the Nelson lung cancer screening trial in which a definitive diagnosis was reached. Cases include hamartomas, scar tissue and granulomas, as well as malignancies such as squamous cell carcinoma, adenocarcinoma and metastases. Nodules will be discussed with their key differential points.Conclusion: Pulmonary nodules can be categorized by evaluating characteristics such as size, growth rate and morphology. Although these are important tools in evaluating a nodule, they do not provide certainty about the nature of a nodule.

C-211 Pulmonary nodules: Reliable growth rate estimates using volume doubling time A.L.M. Leusveld, Y.R. Zhao, D.M. Xu, Y. Wang, M. Oudkerk; Groningen/NL (anneleusveld@gmail.com)

Learning Objectives: 1. To demonstrate the use of Volume Doubling Time (VDT) in the evaluation of pulmonary nodules. 2. To review which nodules are most likely to impede a reliable VDT measurement.Background: Growth rate is an important tool in evaluating the chance of malig-nancy of indeterminate pulmonary nodules. A long VDT indicates that a nodule is likely to be benign, whereas a nodule with a VDT of 400 days or lower has a high risk of being malignant. To measure growth rate, two subsequent scans are needed with reliable measurements. Most reliable are three-dimensional measurements using volumetric software. Reproducibility of measurements for free-standing nodules is high.Imaging Findings: We present representative cases of nodules as found in a lung cancer screening setting. We will demonstrate the procedure of measuring a nodule and how to calculate its VDT. Measurements are reproducible in most cases. However, there are nodule types which may complicate segmentation. Ground glass opacities, partial solid nodules and nodules attached to other pulmonary structures such as vessels and the pleura are difficult to measure. We will discuss these and show how to handle nodules with unreliable measurements.

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Conclusion: Growth measurements are a valuable tool in evaluating pulmonary nodules, with a short VDT as a strong indication of malignancy. This exhibit will pro-vide an overview of the use, as well as of the pitfalls of growth measurements.

C-212 Ground glass nodules: Follow-up in non-symptomatic patients A. Leusveld, Y. Zhao, Y. Wang, D. Xu, M. Oudkerk; Groningen/NL

Learning Objectives: 1. To review the characteristics of ground glass opacities on CT images. 2. To outline the factors that should be taken into account in deciding upon the course of action: follow-up CT or referral to pulmonologist.Background: Focal ground glass opacities (GGO) are increasingly being detected by low-dose CT. It is a non-specific finding that may be caused by various disorders. It may be observed in malignancies such as bronchioloalveolar carcinoma and ad-enocarcinoma. It also may be seen in the presence of benign conditions, including inflammatory disease, interstitial fibrosis and hemorrhage. Distinguishing benign from malignant GGOs is a difficult task. Rapid growth, as well as the appearance of a solid part within the lesion, may indicate malignancy.Procedure Details: We will present representative cases of ground-glass opacities as found in a lung cancer screening setting. We will discuss the characteristics and the differential diagnosis of these lesions. We will also discuss how to manage them in the follow-up and the benefits and limitations of these management options.Conclusion: Evaluation of ground glass nodules based on CT images alone is complicated because reliable segmentation of these nodules is not yet avail-able. Given the fact that premalignant lesions may be stable for a long period, the concept of lead-time should be considered in managing these lesions. An awareness of the clinical setting, in addition to familiarity with the CT features of GGO at initial and follow-up imaging, can help identify malignancy and achieve an accurate diagnosis.

C-213 Cavitary lung lesions: Differential diagnosis M.C.T. Gomes, J. Pires, R. Maia, P. Varzim, M. Ribeiro; Oporto/PT (mantgomes@mail.telepac.pt)

Learning Objectives: 1. To establish the difference between cystic and cavitary lesions. 2. To illustrate the spectrum of diseases that can cause lung cavities. 3. to describe radiological and clinical parameters helpful in the diagnostic evaluation of these patients.Background: Cavitary lung lesions are frequently encountered abnormalities on chest radiography and chest computed tomography. They have a broad differential diagnosis since they can be the expression of many different entities. The first step in the diagnostic process of these lesions is to clearly distinguish between cystic and cavitary lesions since their clinical implications are radically different. Malignancy is the primary concern when evaluating a cavitary lesion while cystic lesions are rarely neoplastic.Procedure Details: Radiological parameters like the thickness of wall cavity, its inner lining, the nature of contents and their location can provide helpful clues to shorten the diagnostic list and to determine a more specific diagnosis. The most common diseases that can cause cavitary lesions are neoplasm, infections (bacteria, fungi and parasites), pulmonary vasculitides (Wegener granulomatosis, rheumatoid nodules), tromboembolism, septic embolism and tracheobronchial papillomatosis.Conclusion: Examples of entities with this type of imagiological presentation will be showed. Clues to the diagnosis of diseases that can manifest as cavitary lung lesions will be discussed.

C-214 Thoracic lymphoma: Tackling the diagnostic dilemma E.J. Goldstraw, H. Verma, N. Bharwani, S. Grubnic; London/UK (egoldstraw@gmail.com)

Learning Objectives: To discuss and illustrate the wide range of imaging findings seen in pulmonary lymphoma and provide an overview of this complex condition.Background: Primary pulmonary lymphoma is rare. However, secondary pulmo-nary lymphoma seen with existing or previous nodal disease is not uncommon and occurs in up to 15% of untreated cases. The disease patterns are extremely variable and an awareness of the spectrum of appearances is essential in order to make the diagnosis.Procedure Details: We will provide an overview of the main differences in behav-iour between Hodgkin’s disease and non-Hodgkin lymphoma in the thorax. The discussion and illustration will concentrate on the wide spectrum of intrathoracic presentations, e.g. consolidation, cavitation, adenopathy. We will discuss the dif-

ferentials and the diagnostic dilemma that this complex condition presents.Conclusion: By the end of this exhibit the reader should: 1. Understand the behavioural differences between Hodgkin’s disease and non-Hodgkin lymphoma with respect to thoracic involvement. 2. Be aware of the spectrum of CT appear-ances in thoracic lymphoma and the diagnostic dilemma this poses. 3. Appreciate the critical role of the radiologist in helping to establish the diagnosis in order to determine further treatment.

C-215 Is surgical anastomosis the only place where bronchial pathology takes place in the lung transplanted patient? C. García-Roch, P. Fraga, M.A. Pastrana, A. De Pablo, G. Mora, M. Diezhandino; Madrid/ES (carmen.roch@gmail.com)

Learning Objectives: 1) To describe normal airway´s features in the lung trans-planted patient and 2) To evaluate pathology at surgical anastomosis and distant from it too by means of multidetector row computerized tomography (MDTC). These results will be correlated with bronchoscopic results in order to establish CT´s ef-ficiency in studying this pathology.Background: The prevalence of major airway complications among lung trans-planted patients remains significant. Pathology often develops both at surgical anastomosis and far from it too. Up to date, CTMD is being considered a useful, accessible tool in valuing this pathology since it offers good correlation with bron-choscopic findings.Procedure Details: From 1991 since February 2007, 347 lung transplants were performed in our centre. We evaluated central airway complications (from traquea to segmentary bronchious), both in suture (such as stenosis, dehiscence and granu-lation tissue growth) and in other airway localizations (chondromalacia, stenosis, infections and tumors) with MDCT. We therefore describe these CT features and correlate them with our bronchoscopic findings.Conclusion: MDCT is a reliable, non invasive diagnostic method in valuing central airway complications in lung transplantated patients, presenting good correlation with bronchoscopic findings.

C-216 Radiologic manifestations of pulmonary nontuberculous mycobacterial infection: A pictorial review R. Maia, P. Santos, M.C.T. Gomes, J. Pires, M. França, J. Reis; Oporto/PT

Learning Objectives: To illustrate the imagiologic spectrum of pulmonary nontu-berculous mycobacterial infection.Background: The nontuberculous mycobacteria (NTMB) are a group of ubiquitous,

low-grade pathogens that typically infect the cervical lymph nodes, skin, soft tis-sues and lung. Pulmonary NTMB infection is increasing in prevalence and is most commonly caused by Mycobacterium avium-intracellulare or M kansasii. The NTMB usually cause chronic, indolent pulmonary infection. The symptoms and the severity of infection depend on several factors, including the presence of underlying lung disease and the patient’s immune status.Imaging Findings: Diagnosis of pulmonary NTMB infection is often difficult because isolation of the organism from sputum or bronchoalveolar lavage fluid may represent airway colonization and not infection. The radiologic manifestations of pulmonary NTMB infection are protean, and often subtle, and can be indistinguishable from those of tuberculosis. Knowledge of the full spectrum of findings is important to facilitate diagnosis and treatment. The authors review the classification of NTMB species and the radiologic manifestations of pulmonary NTMB infection.Conclusion: Pulmonary NTMB infection is increasing in prevalence. Diagnosis of pulmonary NTMB infection is difficult because the organism can colonize the airways. Definitive diagnosis may require biopsy. Classic NTMB infection has clinical and radiologic features similar to those of tuberculosis, but is usually more indolent than active tuberculosis. The CT features of nonclassic NTMB infection are characteristic: bronchiectasis and centrilobular nodules isolated to or most severe in the lingula and middle lobe. M avium-intracellulare infection is the most common NTMB infection in AIDS patients.

C-217 High resolution computed tomography findings of the lungs in febrile neutropaenic patients Z. Khaleel, R. Lavakumar, G. Avery, V. Arora; Hull/UK (ziyadlk@hotmail.com)

Learning Objectives: To review high-resolution computed tomography (HRCT) appearances of pulmonary abnormalities in febrile neutropaenic patients.Background: Immunosuppression in general and neutropenia in particular is frequently induced by high-dose chemotherapy, haematological malignancies

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and bone marrow ablation in bone marrow transplant recipients. In the context of neutropenia, the presence of fever (temperature 38.3 °C) is highly suggestive of infection by a pathogen(s) from a specific array of microorganisms. The lung is the most frequently involved organ. Furthermore, non-infectious pulmonary com-plications such as haemorrhage, oedema, drug toxicity and underlying disease infiltration are equally common.Imaging Findings: We will review the HRCT pattern in: 1) Fungal infection: large peripheral nodules with or without “the halo sign”, wedge shaped air-space con-solidation and peripheral ground-glass attenuations. 2) Typical bacterial infection: non-segmental focal air-space consolidation/ground-glass opacities with cavitation. 3) Atypical bacterial infection: centrilobular nobules, tree-in-bud appearances and ground-glass attenuations. 4) Viral infection: diffuse small nodules and air-space consolidations. 5) Non-infectious complications: haemorrhage, drug toxicity (bilateral ground-glass attenuations or consolidation) and pulmonary oedema (interlobular septal thickening, ground-glass attenuations and pleural effusion).Conclusion: Early and accurate diagnosis of pneumonia is imperative because of the high morbidity and mortality associated with infection in neutropaenic patients. HRCT characterization of pulmonary infiltrates offers an initial and rapid clue to diffrentiate between different types of infectious and non-infectious aetiologies. Moreover, HRCT may also guide further diagnostic and therapeutic techniques (e.g. bronchalveolar lavage, lung biopsy and surgery). Lastly, HRCT is a key modality for follow-up and monitoring of treatment response.

C-218 Non-infectious pulmonary complications of HIV infection: A pictorial review D.R. Vummidi, R. Siripurapu, C. Allen; Manchester/UK (drvummidi@gmail.com)

Learning Objectives: To illustrate the imaging spectrum of non-infectious pulmo-nary complications of HIV infection in the adult population.Background: Advances in the treatment of HIV infection, particularly highly active antiretroviral therapy (HAART) have resulted in increased survival among HIV-positive individuals. Pulmonary disease remains the leading cause of mortality and morbidity with infectious complications being most prevalent; however, with improved survival non-infectious pulmonary complications are being more widely recognized.Imaging Findings: The imaging features of infectious complications of HIV are well described, whereas the non-infectious complications are less well appreciated. These include various airway, interstitial, vascular and neoplastic disease processes such as acute bronchitis, obliterative bronchiolitis, follicular bronchiolitis, emphy-sema, HIV-related pulmonary hypertension, lymphocytic interstitial pneumonitis (LIP), non-specific interstitial pneumonitis (NSIP), Kaposi’s sarcoma, lymphoma and lung cancer. The imaging features of the immune reconstitution inflammatory syndrome (IRIS) are also discussed.Conclusion: We present a pictorial review of the non-infectious pulmonary com-plications of HIV in the adult population. Familiarity with the spectrum of these non-infectious pulmonary disease processes and their imaging features is important for all medical personnel involved in their care due to the implications on diagnosis and management.

C-219 Neuroendocrine pulmonary tumors D. Chourmouzi, L. Papadopoulou, G. Boulogianni, A. Drevelegas; Thessaloniki/GR (dchourm@hol.gr)

Learning Objectives: To describe the imaging findings of neuroendocrine tumors of the lung with histological correlation.Background: Pulmonary neuroendocrine tumors comprise typical and atypical carcinoid and small (SCNEC) and large cell (LCNEC) neuroendocrine carcinoma. They arise from Kulchitzky cells of the bronchial mucosa, display certain mor-phologic features and demonstrate positive immunohistochemical staining for neuroendocrine markers (cromogranin A, synaptophysin, NCAM).Imaging Findings: Typical and atypical carcinoids appear as round or ovoid-paral-lel to bronchi nodules or masses, usually centrally located, with or without a small endoluminal component. They may contain calcifications and may be associated with hilar or mediastinal lymphadenopathy. LCNEC are usually peripherally located, lobulated and contain air-lucencies or necroses. Pleural effusion can sometimes be seen. SCNEC are usually centrally located and associated with hilar or mediastinal lymphadenopathy. They may contain calcifications and provoke pleural effusion.Conclusion: It is important for the radiologists to have an awareness of the imaging findings of the above-mentioned lung tumors. Imaging findings can help differentiate between these tumors. The presence of a well-defined central or peripheral pulmonary nodule or mass, with punctuate or diffuse calcifications, associated with pleural effusion and lymphadenopathy, should always raise the suspicion of a neuroendocrine tumor.

C-220 What is your diagnosis for nodular ground-glass opacity? Emphasis on CT features related to malignancy and its prognostic value H. Lim, C. Park, J. Goo, H. Lee, C. Lee, J.-G. Im; Seoul/KR (dearyouni@radiol.snu.ac.kr)

Learning Objectives: To illustrate significant CT findings of nodular ground-glass opacity (NGGO), its changes over time, and prognostic value on thin-section CT.Background: Early lung cancer CT screening trial and widespread availability of MDCT raised the frequency of NGGO detection. NGGO may be seen in benign conditions such as focal interstitial fibrosis, inflammation, and hemorrhage. But they also are seen in early lung cancer or its precursor, and at the early stage, only limited resection can obtain excellent prognosis. The significant CT features related to malignancy of NGGO and its prognostic value are described and illustrated.Imaging Findings: Persistent NGGO is suggestive of early-stage adenocarcinoma or malignancy precursor. NGGO with a solid component (mixed NGGO) has a higher malignancy rate than pure NGGO, and a large solid proportion raises the probability of malignancy. Bubble lucency, air-bronchogram or pleural retraction may also be seen in mixed NGGO. Furthermore, malignant NGGO has a close relation with the lesion size ( 1 cm), lobulation and spiculation. In contrast, pure NGGOs are usually multiple and have smooth margin and round shape. On follow-up CT, NGGO shows progression such as newly appeared solid portion and increase in size and opacity. These changes are also related to malignancy. For disease prognosis, lower internal solid proportion ( 50%) and smaller size ( 2 cm) are good, whereas coarse spiculation and bronchovascular bundle thickening have higher metastasis rate.Conclusion: Malignancies such as AAH, BAC and adenocarcinoma should be suspected for persistent NGGO. Meticulous evaluation of the initial and follow-up CT can result in the accurate diagnosis.

C-221 Parenchymal sparing techniques in surgical treatment of central bronchogenic carcinoma: Pre-operative and post-operative assessment with MDCT M. Mereu, P. Santodirocco, P. D’Ambrosio, V. Di Mizio, P. Camplese, M.L. Storto; Chieti/IT (m.mereu@rad.unich.it)

Learning Objectives: 1) To describe the most frequently used parenchymal spar-ing and tracheal sleeve techniques for lung cancer surgical treatment. 2) To define MDCT findings in the pre-operative assessment of eligible patients for parenchymal sparing surgery. 3) To discuss MDCT findings in the post-operative follow-up of such patients for a correct and early diagnosis of complications.Background: MDCT has revolutionized non-invasive imaging of central airways allowing the scan of the entire lung in a few seconds with maximum spatial resolu-tion. In patients with central bronchogenic carcinoma, a thorough assessment of tumor extent and relationship with mediastinal and hilar structures is important in order to assess resectability, expecially after the introduction of new surgical techniques, which allow sparing of lung parenchyma and thus reduce the need for pneumonectomy.Procedure Details: Different pulmonary resection techniques including sleeve pneumonectomy, sleeve lobectomy, tracheal sleeve pneumonectomy, and other surgical parenchimal sparing techniques will be described and illustrated with clini-cal cases. Potential post-operative complications including bleeding, atelectasis, pneumonia, persistent air leak, bronchopleural fistula, empyema, anastomotic dehiscence, anastomotic stenosis, and recurrent tumor were also discussed.Conclusion: The radiologist should be familiar with the different and newest surgi-cal techniques of pulmonary resection in patients with bronchogenic carcinoma in order to correctly identify patients for parenchymal sparing surgery and to correctly assess early complications in the post-operative course.

C-222 Pulmonary sarcoidosis: Typical and atypical radiological manifestations on HRCT in histologically confirmed cases E. Criado Paredes, M. Sánchez González, P. Arguís Giménez, F. Calaf Forn, J. Ramírez, T.M. de Caralt Robira, M.J. Perea Palazón, A. Xaubet; Barcelona/ES (eva-criado@hotmail.com)

Learning Objectives: To recognise the widespread spectrum of both typical and atypical radiological manifestations, which pulmonary sarcoidosis can produce on HRCT, through a review of biopsy-proven cases. To review the main differential diagnosis in each case.Background: Up to 50% of patients with sarcoidosis are diagnosed as incidental radiological findings. Pulmonary parenchyma and both the mediastinal and hilar

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lymphatic nodes are the main affected areas, accounting for most of the morbidity and mortality associated with this disease.Imaging Findings: Typical manifestations of lymphadenopathies are: both me-diastinal and hilar, and bilateral and symmetrical. Atypical manifestations are: unilateral and asymmetrical, and calcifications (punctuate, amorphous, popcorn, or eggshell). Typical manifestations of parenchymal opacities are: peri-lymphatic micronodules (subpleural, peribronchovascular, and along interlobular septa), fibrotic changes with parenchymal distortion and bronchiectasis that involve pre-dominantly middle-upper zones. Atypical manifestations are: pulmonary nodules and masses, sometimes cavitated, patchy ground-glass consolidation areas, “pseudo-pleural” plaques, air trapping, mycetomas, and atelectasis. Other atypical thoracic manifestations are: tracheo-bronchial involvement, pleural effusion, pleural thickening, and pneumothorax.Conclusion: Pulmonary sarcoidosis can develop in many radiological patterns and is therefore known as the “great mimic”. Up to 90% of the affected patients will present radiological thoracic abnormalities at some stage of the disease. Only if we take into account all the multiple appearances and know the clues for its recognition, will we be able to include this entity within the differential diagnosis of many radiological patterns. Nowadays, the role of radiologists, in interpreting HRCT, is essential in order to reach an early diagnosis of this disease that sometimes may be confusing.

C-223 Atypical pulmonary metastases simulating benign disease: A CT pictorial review J. Ni Mhuircheartaigh1, B. Sabloff2, T. Mylene2, C. Roche1, J. Bruzzi1; 1Galway/IE, 2Houston, TX/US (jnimhuircheartaigh@gmail.com)

Learning Objectives: To illustrate unusual and atypical appearances of pulmo-nary metastases on CT that may be mistaken for alternative diagnoses by the unsuspecting radiologist.Background: For most malignancies, pulmonary metastases are a late presenta-tion of disease dissemination and most commonly present as discrete pulmonary nodules or lymphangitis. Occasionally, pulmonary metastases may be clinically unsuspected and present with an unusual appearance, mimicking other benign pathologies. The recognition of such a presentation is clinically important for for-mulating correct treatment strategies.Imaging Findings: Examples of atypical pulmonary metastases on CT include endovascular nodules (simulating pulmonary emboli or bronchiolitis), endobron-chial nodules (simulating endobronchial mucoid impaction or bronchocoeles), thin-walled cysts (simulating pneumatocoeles or emphysematous bullae), highly vascular nodules and masses (simulating pulmonary arteriovenous malformations) and perivascular metastases with associated haemorrhage (simulating fungal pneumonia). In each case, failure to recognise the true nature of the abnormality may lead to delayed or erroneous treatment.Conclusion: For the oncology radiologist, it is important to be aware of the varied appearance on CT of pulmonary metastases in certain malignancies. It is es-sential to have an understanding of the pathophysiology underlying such atypical presentations, in order to optimise diagnostic interpretation and help avoid potential confusion with benign disease.

C-224 Pulmonary amyloidosis: The great pretender E. Kelliher1, C. Meehan1, A. Browne1, J. Ni Mhuircheartaigh1, P. O’Sullivan2, J. Bruzzi1; 1Galway/IE, 2Houston, TX/US (emma_kelliher@yahoo.com)

Learning Objectives: To familiarise the reader with the spectrum of appearances of amyloid disease on thoracic imaging and illustrate how it can simulate other benign and malignant diseases.Background: Pulmonary amyloidosis has been classified as pulmonary involve-ment associated with systemic amyloidosis (primary, secondary or familial systemic amyloidosis), localized pulmonary amyloidosis (which may have a tracheobronchial, nodular parenchymal or diffuse interstitial pattern) and mediastinal/hilar amyloido-sis. The diagnosis of pulmonary amyloid associated with systemic amyloid may be inferred from the presence of biopsy-proven amyloid disease in other organs. Primary pulmonary amyloid, however, is difficult to diagnose prospectively as its varied spectrum of appearances may mimic other benign and malignant pathological conditions and lead to diagnostic confusionImaging Findings: Illustrated examples will be provided of typical and unusual presentations of pulmonary amyloidosis on plain film, CT and PET/CT imaging, emphasising the ability of pulmonary amyloidosis to be confused with other disease processes such as cardiogenic pulmonary oedema, granulomatous infection, lung cancer and metastatic disease

Conclusion: Pulmonary amyloid has a widely variable presentation on imaging studies and may simulate other more common conditions. It is important for the interpreting radiologist to be familiar with these appearances and to be cognisant of the patient’s medical history in order to avoid diagnostic confusion.

C-225 Primary lung cancer complicated with pneumothorax following chemotherapy or radiation therapy: Emphasis on various CT features and correlation with pathogenesis J. Kim1, H. Kim2, K. Lim2, S.-H. Lee2; 1Seoul/KR, 2Goyang/KR (mine147@radiol.snu.ac.kr)

Learning Objectives: To identify the clinical and radiological findings of pneu-mothorax following thoracic irradiation or chemotherapy in primary lung cancer. To describe the feasible pathogenesis of pneumothorax, after chemotherapy and irradiation, with correlative CT images.Background: Spontaneous pneumothorax in primary lung cancer is relatively rare ( 1%) compared with other malignancies, especially sarcoma or teratoma. It is either the first manifestation of cancer or a complication arising from irradiation or chemotherapy. Between September 2001 and February 2007, 62 out of 3,469 patients experienced spontaneous pneumothorax following chemotherapy or ir-radiation. We reviewed clinical, radiological, and pathologic data of pneumothorax. In this exhibit, we will discuss not only the various clinical and imaging features of chemotherapy or radiation-induced pneumothorax, but also its possible pathogen-eses with correlative images.Procedure Details: Most of the pneumothorax occurred unilaterally (n = 51, 82%), i.e. the same hemithorax as the primary lung lesion, in seven patients contralaterally and in four bilaterally. A total of 53 patients (53/62, 85%) experienced concurrent pleural effusion and 3 patients had pneumomediastinum. Only 15 cases (15/62, 24%) were identified on chest radiograph and 37 cases of pneumothorax (37/62, 62%) resolved spontaneously. Feasible pathogeneses of pneumothorax could be classified into three categories and each category showed distinctly characteristic CT features: 1) rupture of subpleural bleb or bullae secondary to radiation fibrosis or rapid tumor shrinkage; 2) central or peripheral bronchopleural fistula formation; 3) peripheral small metastatic necrotic nodule rupture.Conclusion: Spontaneous pneumothorax of primary lung cancer following chemo-therapy or irradiation demonstrates various clinical and CT features.

C-226 Silicosis: Analysis of CT findings L. Xu, W. Peng; Shanghai/CN (jeniferxlh@hotmail.com)

Purpose: To improve the diagnostic accuracy of silicosis by investigating its CT appearances.Methods and Materials: Appearances of CT in 45 patients with silicosis diagnosed by occupational diseases prevention and treatment institute of Zhejiang province were analyzed retrospectively. All these patients were male, aged 42~71 (mean age, 56). 5 cases were stage I, 18 were stage II, and 22 were stage III. All patients underwent plain CT scan, and CT findings of lung parenchyma, hilus, mediastinum, and pleura were examined.Results: CT appearances of silicosis included: 1. lung parenchyma (1) All cases showed diffuse small nodules; (2) Progressive massive fibrosis were found in 16 of stage II (16/18), 22 of stage III (22/22) patients; (3) All cases showed fibrous strips and reticular opacities. Central fibers and vascular bundles thickening were found in 2 of stage II (2/18), 5 of stage III (5/22) patients; 8 of stage III (8/22) cases showed obvious interlobular septal thickening and subpleural lines. (4) 3 of stage II (3/18), 8 of stage III (8/22) patients showed emphysema. 2. All cases except 4 of stage I showed enlarged hilar and mediastinal lymph nodes which contained silicon powder; 2 of stage II (2/18), 9 of stage III (9/22) patients showed fleck, mulberry, eggshell calcifications in the hilar lymph nodes. 3. Pleural thickening were showed in 6 of stage II (6/18), 13 of stage III (13/22) cases, some of which showed typical bandlike pleural thickening; none of stage I cases showed this sign.Conclusion: CT features of silicosis are complicated, typical signs include progres-sive massive fibrosis, silicon precipitation and eggshell calcifications in hilar and mediastinal lymph nodes, bandlike pleural thickening. Combining these signs with vocational history will lead to accurate diagnosis.

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C-227 CT screening for asbestos-exposed former workers: Preliminary results K. Ashizawa, K. Nakanishi, S. Tsutsui, T. Kadota, A. Ishiyama, T. Yamaguchi, M. Uetani; Nagasaki/JP (ashi@nagasaki-u.ac.jp)

Purpose: To evaluate the preliminary results of CT screening in a group of former workers with an exposure to asbestos.Methods and Materials: Between January and August in 2006, 652 asbestos-exposed former workers underwent 16-channel MDCT examinations. All workers were men and their age range was 50-89 years. Six workers had a history of sur-gery for lung cancer. CT scans were interpreted independently by two experienced radiologists, and decisions were reached by consensus. Asbestos-related pleural diseases, pulmonary diseases, and malignant lesions were analyzed.Results: Pleural plaques were identified in 405 (62%) workers. They were most commonly located in posterior portion of middle to lower lung zones followed by diaphragm, and 88% of them were seen bilaterally. 90% of pleural plaques had less than 5 mm in thickness, and calcification was identified in 68% of them. Diffuse pleural thickening and pleural effusion were seen in 29 (4%) and 11 (2%) workers, respectively. Asbestosis and rounded atelectasis were identified in 91 (14%) and 17 (3%) workers, respectively. At least one non-calcified nodule was detected in 212 (33%) workers, and seven nodules out of them (1.1%) were diagnosed as lung cancer. In one case, pleural effusion and pleural nodular thickening newly appeared three months after the screening and was diagnosed as malignant mesothelioma.Conclusion: The most frequent CT abnormality in asbestos-exposed former workers is pleural plaques, followed by non-calcified nodule, asbestosis, and dif-fuse pleural thickening. Because chest CT can demonstrate a variety of pleural and pulmonary abnormalities, CT screening for asbestos-exposed former workers is useful.

C-228 Analysis of asbestos-related lung cancer found in screening for former workers A. Ishiyama, K. Ashizawa, T. Hayashi, K. Nakanishi, T. Kadota, S. Tsutsui, M. Uetani; Nagasaki/JP

Purpose: To evaluate the asbestos-related lung cancer found in screening in a group of former workers with an exposure to asbestos.Methods and Materials: Between January and August in 2006, 652 former workers with exposure to asbestos underwent chest radiography and MDCT examinations, and seven lung cancers (1.1%) were found. All workers were men and their age range was 55-81 years with mean age of 71 years. All but one workers had a history of smoking (mean Brinkman index: 506). Chest radiographs and CT scans were interpreted independently by two radiologists. Clinical, pathological and radiological correlation in asbestos-related lung diseases was performed.Results: Seven lung cancers were 4 adenocarcinomas (Ad), 2 squamous cell carci-nomas (Sq) and 1 small cell carcinoma (SCLC). According to the TMN classification, four patients were classified as stage IA (3 Ad, 1 sq), 1 as IIIA (Ad), 1 as IIIB (Sq), and 1as IV (SCLC). Four of the seven cancers were detected on chest radiograph, and the remaining three cancers were found only by CT. The presence of asbestosis was demonstrated in 3 patients (2 Sq, 1 SCLC), and pleural plaques were detected in 2 patients (1 Ad, 1 SCLC). In these four patients with asbestosis and/or pleural plaques, the duration of exposure to asbestos was more than 15 years.Conclusion: Asbestos-related lung cancers are found in patients with asbestosis as well as without asbestosis. The frequency of complicated lung cancer is high, and the screening for pulmonary lesions in asbestos-exposed former workers is useful.

C-229 Airway distensibility by HRCT decreases with severity of COPD M. Bellia, F. Cannizzaro, N. Scichilone, A. La Sala, S. Russo, V. Bellia, M. Midiri; Palermo/IT (maria.bellia@libero.it)

Purpose: Airways distensibility, by deep inspiration, as assessed by HRCT, de-creases with severity of asthma, suggesting that this impairment is related to the occurrence of obstructive symptoms. In this study, we assessed whether airway distensibility by HRCT also worsens with severity of COPD.Methods and Materials: Thirteen individuals with a range of severity (GOLD stages, mild-moderate: 5 subjects; severe: 8 subjects) underwent HRCT. Two sets of scans were obtained, one at maximal expiration (residual volume, RV) and the other at maximal inspiration (total lung capacity, TLC). Scans through identical airway lumi-nal locations were selected from each of the sets for each subject using adjacent landmarks, as airway bifurcations or accompanying vessels. Luminal area was measured for each airway at TLC and RV by Image J software package. Changes

in airway areas were calculated as the ratio of the difference in areas at TLC and RV divided by the area at RV. 109 airways were matched and measured.Results: For the whole group and for all airways, inflation from RV to TLC increased airway area by 56 12%. Changes in area were significantly lower in the severe group than in the mild-moderate group (27 7% vs. 87 15%; p=0.003, mean SEM). Airway area changes correlated with indices of airway obstruction (FEV1% pre-dicted: r=0.53, p=0.05; FEV1/FVC: r=0.60, p=0.02) and with indices of air trapping (RV/TLC: r= -0.58, p=0.03).Conclusion: These findings suggest that airway distensibility decreases with in-creasing severity of disease, supporting the notion that attenuation of the tethering forces on airways contributes to obstructive symptoms.

C-230 Pulmonary nodular ground-glass opacities in patients with extrapulmonary cancers K. Kim1, C. Park2, H. Lee2, T. Kim3, C. Lee2, H. Lee2, E.-A. Park2, J.-G. Im2; 1Goyang/KR, 2Seoul/KR, 3Bundang/KR (kimkg@ncc.re.kr)

Purpose: To investigate the clinical significance of pulmonary nodular ground-glass opacities (GGOs) in patients with extrapulmonary cancers and to develop a computerized scheme to distinguish malignant from benign nodular GGOs in these patients.Methods and Materials: Between January 2002 and March 2007, we identified 43 patients with pulmonary nodular GGOs and history of extrapulmonary cancer from two tertiary hospitals. We reviewed the CT characteristics of the nodular GGOs and the clinical features of these patients. Artificial neural networks (ANNs) with multilayer perceptrons were used to distinguish malignancies from benignities.Results: Twenty-eight of 43 patients (65.1%) were determined to have malignancies showing nodular GGOs. On a nodule basis, 71 nodular GGOs in 43 patients were diag-nosed: 24 lesions (33.8%) were adenocarcinomas, 16 bronchioloalveolar carcinomas (22.5%), 14 atypical adenomatous hyperplasias (19.7%), 4 focal fibrosis (5.6%), one inflammatory nodule (1.4%), and 12 benign lesions that decreased or disappeared over several months’ follow-up (16.9%). Between the malignancy and benignity, there were significant differences in lesion size, CT classification of the lesion, size of the internal solid component, border and margin of the lesion, and presence of bubble lucency, air bronchogram, or pleural retraction (P 0.05). ANNs showed excellent accuracy (area under the ROC curve, 0.973) in discriminating malignancies from benign lesions.Conclusion: Pulmonary nodular GGOs in patients with extrapulmonary cancers tend to have high malignancy rates and are very often primary lung cancers. ANNs with multilayer perceptrons can be a useful tool in distinguishing malignancies from benignities.

C-231 Usual interstitial pneumonia (UIP) under treatment: High resolution computed tomography (HRCT) changes observed under interferon-gamma-1b and colchicine K. Malagari, E. Emmanouil, D. Letsou, D. Antonopoulos, E. Alexopoulou, S. Argentos, P. Vasiliou, A. Gouliamos; Athens/GR (kmalag@acn.gr)

Purpose: To report on the qualitative and quantitative changes of high resolution computed tomography (HRCT) in usual interstitial pneumonia (UIP) under treat-ment with interferon gamma-b (IFN- -1b) compared with colchicine and low-dose prednisolone treatment.Methods and Materials: Patients with documented UIP (n=41) having been randomly assigned for treatment with IFN- (n = 27) or colchicine (n=14) were included. HRCT examinations at baseline and one year after treatment were as-sessed for morphology and extent of disease (visual HRCT score). Results from the IFN- -1b patient group were compared with those of the colchicine group serving as control.Results: Mean baseline extent of fibrosis at HRCT was 35.34 10.45 % (mean SD; range 14-59). For the IFN- -1b baseline HRCT scoring was 32.90 8.73 % (mean SD; range 14-48) while for controls on colchicine was 40.0 12.2% (mean SD; range 23-59). There was no statistically significant difference at base line between the two groups (Mann-Whitney U: p=0.184).The mean value of HRCT progress score from both readers was 3.717 0.7321 (range 1.9-4.9). There were no statistical differences of progression scores between the two patient groups (p=0.1409). Complete resolution of the ground glass opacities was observed in a total of 3 patients (1 of IFN- -1b and 2 of the colchicine group). The remaining (82.92%) presented features of deterioration, coarsening of the reticular pattern with replacement of the microcystic pattern to a macrocystic (honeycomb) or development of new areas of ground glass.Conclusion: HRCT does not reveal morphological structural differences with the use of IFN- -1b compared to conventional colchicine treatment. However, longer follow-up is essential for more solid results.

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C-232 Evaluation of small airways in healthy, COPD and asthmatic individuals using high resolution computed tomographyK. Gao1, L. Zhang1, J. Li1, S. Dutta2; 1Beijing/CN, 2 Waukesha, WI/US (jianying.li@med.ge.com)

Purpose: To characterize changes of small airways of healthy, COPD and asth-matic subjects after 5 deep inspirations (DI) using high resolution CT (HRCT) and airway detection software.Methods and Materials: HRCT chest scans were performed in 29 mild asthma, 55 COPD and 35 healthy subjects before and after 5 DI. High-resolution reconstructions with small FOV were performed to improve the visualization of small airways. The airway software package being developed by GE Healthcare was used to assess right lower lobe airways ( 2 mm) by measuring airway inner and outer diameters. Parameter changes before and after 5DIs for the three groups were measured and statistically analyzed to find correlations between airway parameter change and disease stage.Results: A total of 564 small airways with diameters from 1.2 mm to 2 mm were detected from the HRCT images. For the small airways in healthy group both the inner and outer diameters had statistically significant increase after 5DI (p 0.05). For the mild asthma patients, only inner diameters showed statistically significant increase, while the small change in outer diameter was not statistically significant. For COPD patients, there was no change in the airway parameters after 5 DI.Conclusion: Small airways behave differently for healthy persons and patients with mild asthma and COPD. 5 DI may relax the small airways and decrease the elastic resistance in the healthy subjects. However, such decrease reduced and diminished in mild asthma and COPD patients, respectively. HRCT combined with airway analysis tools is capable of detecting changes quantitatively in small airways.

C-233 Pulmonary veins crossing pleural fissures: A cause for false positive findings in low-dose CT exams performed for early lung cancer detection A. Villanueva, M.L. Díaz, A. Alonso-Burgos, C. Hernández, G. Bastarrika, B. Zudaire, J.C. Pueyo, J. Larrache, L. Garcia del Barrio, M. Arraiza, M.J. Herraiz, J. Arias, J. Broncano; Pamplona/ES (avillanueva@unav.es)

Purpose: Detection of pulmonary nodules that could potentially represent lung cancer at an early stage is the objective of low-dose CT performed of lung can-cer screening. In these programs, follow-up CT of small pulmonary nodules is performed to avoid unnecessary invasive procedures. Pulmonary veins crossing pulmonary fissures mimic pulmonary nodules and, thus, represent false positive findings. The purpose of this study was to determine the prevalence of theses pseudonodules (PN).Methods and Materials: From January to June 2007, 396 LDCT exams were performed for early lung cancer detection using a 64-row MDCT. Two observers independently analyzed these studies on a satellite console. Pseudonodules were defined as nodular areas of increased density inside a pulmonary fissure connect-ing with a pulmonary vein. Studies were retrospectively compared with previous exams. Size, density, shape, location, and connection with pulmonary veins of each PN were evaluated.Results: A total of 14 PN on 12 patients was detected, most of which were right sided (66%). In 8 cases, no communication with the pulmonary vein was observed on 3 mm slice thickness images. On 1 mm images continuity was found in all cases. 33% of PN were located within the minor fissure. 90% of PN were greater than 5 mm. None of the evaluated PN had increased in size when compared with previous 3-12 month exams. One PN revealed contrast filling on a previous CT.Conclusion: The prevalence of 3.5% PN was found in this series. Appropriate interpretation of this finding might avoid unnecessary follow-up CT exams.

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Pathology

C-234 Spectrum of imaging findings in bronchioloalveolar carcinoma with pathologic correlation J.F. Costa, A. Canelas, A. Costa, L. Teixeira, L. Carvalho, F. Caseiro-Alves; Coimbra/PT (joaofilipegmc@sapo.pt)

Learning Objectives: To illustrate the spectrum of radiologic features of bron-chioloalveolar carcinoma (BAC) of the lung based on surgical specimens and according to the new diagnostic criteria. To correlate the imaging findings with pathologic examinations.Background: Most previous studies did not meet the 1999/2004 revised World Health Organization (WHO)/International Association for the Study of Lung Cancer (IASLC) diagnostic criteria for BAC and their diagnosis was mostly based on small bronchial, transbronchial, or transthoracic needle biopsy, which could include patients with a mixture of BAC and other histologic subtypes, including an inva-sive component. Because early, localized, nodular bronchioloalveolar carcinoma is potentially curable, awareness of the radiologic findings in the early stage of bronchioloalveolar carcinoma and of diverse radiologic features of the disease is essential for radiologists.Procedure Details: The authors reviewed the imaging findings of BAC, based on a series of patients (n=25) with diagnosis confirmed by microscopic examination of surgically resected lung specimens. The nodular form was the most common (56%) appearance of the BAC, followed by the diffuse (33%) and consolidative (11%) form. Associated findings included spiculated margins, ground-glass attenuation, pleural tag, pseudo-cavitation, the open bronchus sign, the CT angiogram sign and cavitated consolidation. Nonmucinous BAC was the most common pathologic type. Mucinous type was more prevalent in the multicentric forms.Conclusion: Due to its polymorphic imaging presentation, BAC findings are in general non-specific. A single nodular parenchymal mass with ground-glass attenuation areas and spiculated margins are evocative of the diagnosis in the proper clinical setting.

C-235 Imaging spectrum in bronchial carcinoid tumor of the thorax: Radiologic with surgical and pathologic correlation J.J. Cortes Vela, J. Arenas Jiménez, J.M. Corcoles Padilla, J.M. Garcia Marco, S. Bolufer Nadal, J. De La Hoz Rosa; Alicante/ES (jesusjcortes@hotmail.com)

Learning Objectives: To show the wide spectrum of radiological findings in bronchial carcinoid tumors of the thorax in chest radiograph and multidetector CT (MDCT) with emphasis on surgical and pathologic correlation.Background: Bronchial carcinoid tumors are neuroendocrine neoplasms of the lung and account for 1-2% of all lung tumors. Histologically they have been divided in typical and atypical with similar radiologic features. Bronchial carcinoid may present a wide spectrum of clinical behavior and histologic features.Imaging Findings: Most frequently bronchial carcinoids arise centrally and manifest as hiliar or perihiliar mass or as a small nodule located within the lumen of a bronchus. Because of its central location they may show findings related to bronchial obstruction such as atelectasis, air trapping, obstructing pneumonitis, mucoid impaction and recurrent infection distal to the tumor that can result in bron-chiectasias or even lung abscess. MDCT can show the relationship of the tumor with airway in order to plan surgery. Peripheral bronchial carcinoids are located distal to segmental bronchi. They usually appear as solitary round or ovoid lesions with smooth or lobulated borders. Calcification can be seen in up to 30% of tumors. In patients with hemoptysis a zone of ground-glass attenuation surrounding the nodule (halo sign) may be seen. Hiliar or mediastinal lymphadenopathy and metastases can appear, usually in atypical carcinoids.Conclusion: The most common clinical presentation and radiological findings in bronchial carcinoid tumors are related to proximal bronchial obstruction. Tumor evaluation with MDCT can help planning the surgical approach to perform con-servative resection when feasible.

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C-236 Morphologic and pathophysiologic evaluation of the peripheral lung using ultra-high-resolution CT H. Ikura1, K. Shimizu1, M. Ikura1, T. Mochizuki2, T. Nagareda3, Y. Imai4; 1Tokyo/JP, 2Ehime/JP, 3Hyogo/JP, 4Kanagawa/JP (ikura-circ@umin.ac.jp)

Learning Objectives: 1) To demonstrate peripheral remodeling in some chronic lung diseases using ultra-high-resolution CT (UHRCT). 2) To correlate the mor-phologic findings of UHRCT with pathology. 3) To diagnose various lung diseases morphologically and pathophysiologically, with UHRCT, and also microscopically.Background: The morphologic remodeling in chronic lung disease has been well recognized in clinical imaging. However, we often experience difficulty in understand-ing the pathophysiology even with such morphologic findings. UHRCT, synchrotron radiation CT (SRCT) and micro-focus-X-ray CT (MFXCT) can depict alveolar wall with 10 μm of spatial resolution.Procedure Details: Postmortem human lungs were inflated and fixed by Heitzman’s method. The specimens included normal state, pneumonia, alveolar hemorrhage, ARDS, hypersensitivity pneumonitis, COPD, pulmonary fibrosis, old tuberculosis, solid lung carcinoma, and BAC. UHRCT images were obtained with a SRCT system constructed in SPring-8 (Hyogo, Japan) and a MFXCT system (MCT-CB100MF, Hitachi Medica1 Co Ltd. Japan). The CT images of the normal and pathologic lung specimen correlated with the corresponding histopathology, point to point. In BAC, UHRCT findings demonstrated interstitial thickening with serration of carcinoma cells lying on the alveolar wa11. In pulmonary fibrosis, the gas-exchanging area was definitely decreased due to traction dilatation. In emphysema, UHRCT demonstrated the peripheral destructive dilatation like ballooning, which seemed to narrow the peripheral bronchioles. The finding indicated peripheral check-valve mechanism.Conclusion: UHRCT can provide 2-D and 3-D information of lung periphery in a nondestructive manner. The knowledge of peripheral remodeling would help us to understand the pathophysiology in our daily diagnosis.

C-237 Assessment radiologic-pathologic: Image-guided 25-gauge needle like accurate and safe lung lesions diagnosis in 785 patients E. Valbuena, V. Suarez, I. Torres, M. Pardo, P. Lopez Ferrer, A. Mariño Enríquez; Madrid/ES (emiliovalbuena@hotmail.com)

Purpose: To report our experience in lung lesions diagnosis, including complica-tions, by means of image-guided 25-gauge needle aspiration cytology in the greatest series of patients to our knowledge. To assess radiologic-cytologic correlation.Methods and Materials: At our institution, 785 patients with lung lesions underwent 25-gauge needle aspiration with CT-guidance during the past 15 years. Specimens obtained were immediately smeared and stained with Diff-Quik to evaluate if satisfactory material had been obtained. We selected for this study 193 patients whose radiologic studies, cytologic smears and surgical samples were available for review. Radiologic diagnosis was classified in three categories retrospectively by staff-radiologist: positive-malignant, negative-benign and indefinite. For correlation purposes, cytologic diagnosis was categorized in negative, positive or suspicious for malignancy, and not representative. Surgical pathology samples were classified as negative or positive for malignancy.Results: Most of the specimens obtained with a 25-gauge needle were considered “adequate” for evaluation. Pneumothorax occurred in 147 (19%) of 785 aspirations. Minor hemoptysis occurred in 3 patients ( 1%), but massive hemoptysis did not occur. There were no fatalities. Correlating with biopsy diagnosis, the sensitiv-ity for the detection of malignancy by radiological diagnosis was 99%, and the specificity was 24%. Cytological diagnosis achieved 79% of specificity, with 89 % sensitivity. Anyway, on both sides the positive predictive value was high, 92% and 97%, respectively.Conclusion: Image-guided 25-gauge fine-needle aspiration cytology is a safe and accurate procedure for diagnosing chest lesions. The interdisciplinary col-laboration between cytologists and radiologists is imperative to achieve a high diagnostic accuracy.

C-238 Clinical/pathologic correlations in 553 patients with primary centrilobular findings on HRCT of the thorax F. Okada, Y. Ando, S. Tanoue, S. Matsumoto, H. Mori; Yufu/JP (fumitook@med.oita-u.ac.jp)

Purpose: Clinical/pathologic correlations in patients with HRCT findings presenting with two patterns of centrilobular opacities remain unclear.Methods and Materials: Chest HRCT scans in 553 patients with predominant centrilobular opacities or preferentially centrilobular disease were retrospectively

evaluated. In 141 patients who underwent biopsy, CT images were compared with actual specimens.Results: Centrilobular nodules with tree-in bud appearance and bronchial wall thickening were observed in most of patients with HTLV-1 carriers (88, 57 of 99), mycoplasma pneumoniae pneumonia (44, 45 of 52), mycobacterium tuberculo-sis [Tb] (38, 37 of 52), mycobacterium avium-intracellulare complex [MAC] (22, 27 of 37), mycobacterium Kansasii (27, 19 of 33), allergic bronchopulmonary aspergillosis [ABPA] (6, 7 of 9), diffuse panbronchiolitis [DPB] (12, 10 of 12), and diffuse aspiration bronchiolitis [DAB] (12, 12 of 13), respectively. On the other hand, ill-defined centrilobular nodules of ground-glass attenuation [GGA] were frequently seen in patients with subacute hypersensitivity pneumonitis [HP] (all of 15), metastatic calcification (all of 4), Churg-Strauss syndrome [CSS] (4 of 12), microscopic polyangiitis [MPA] (27 of 48), systemic lupus erythematosus [SLE] (all of 8), and respiratory bronchiolitis-associated interstitial lung disease [RB-ILD] (all of 8). Pathologically, the tree-in-bud appearance correlated well with plugging of small airways with mucous, pus, or fluid; dilated bronchioles; and bronchiolar wall thickening. Ill-defined centrilobular nodules represented peribronchiolar inflamma-tion or deposition of hemorrhagic materials.Conclusion: Knowledge of the two centrilobular patterns is of proven worth for generating differential diagnoses and is of particular value in suggesting a likely infectious etiology in cases with tree-in-bud appearance.

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PET

C-239 Unsuspected metastases demonstrated on PET-CT in patients with non-small cell lung carcinoma C.P. Mullan, O. McNally, T. Lynch; Belfast/UK (cpmullan@hotmail.com)

Learning Objectives: To identify the diverse nature of NSCLC metastases identified with PET-CT that would not be detected by conventional CT staging.Background: PET-CT has significantly improved the staging of non-small cell lung cancer. Many patients are upstaged by the accurate identification of nodal and metastatic disease. Although the liver and adrenal glands are common sites of metastatic deposition, the whole body imaging provided by PET-CT enables other sites of systemic metastatic spread to be detected.Imaging Findings: At our department, it is routine practice to perform a staging PET-CT examination in all patients with NSCLC, who could potentially benefit form surgery or radial radiotherapy. We present a pictorial review of systemic metastases identified with PET-CT that would not have been detected by conventional CT.Conclusion: Our experience of using PET-CT over the past 5 years clearly shows that NSCLC metastases may already be present at less typical sites at the time of initial disease staging.

C-240 Significant incidental CT findings identified on PET-CT unrelated to the primary pathology: Does the CT component of PET-CT need formal reporting? R. Kirke, D. Barnes, J. Raj, R. Coulden, J. Entwisle; Leicester/UK (rathy.kirke@uhl-tr.nhs.uk)

Purpose: The aim of this study was to determine the prevalence of incidental findings on the CT component of FDG PET-CT performed for staging/managing malignancy, ie significant pathology only visible on CT.Methods and Materials: 300 consecutive 18 FDG CT-PET studies performed at our institution from the 1st of January 2007 were retrospectively reviewed. Any significant pathology identified on the low dose CT component of the PET-CT examination but not visible on PET were recorded. CT abnormalities were classified as being minor (no clinical intervention needed), moderate (non urgent clinical management may be required) and major (prompt clinical intervention or referral). When the abnormality lay outside the field of view of the previous CT, this was also recorded.Results: 32 (10.5%) incidental and new abnormalities were present in 300 patients (178 men and 122 women). 4 (1.3%) were of major significance. 14 (4.5%) were of moderate significance and 14 (4.5%) of minor significance. 2 of the major ab-normalities were new (hydronephrosis and pneumothorax). These had developed in the interval between the staging/previous CT and the PET-CT.Conclusion: The CT component of PET-CT represents a whole body CT, albeit low dose and in 3 mm slices, that needs to be systematically reviewed and reported in its own right. This is particularly important for disease in areas not covered by previous CT and new pathology that has developed since. PET-CT reporting requires the reporter to be fully trained in both modalities.

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Technical Aspects

C-241 CT guided percutaneous needle biopsy of the lung: Technical considerations and outcomeS.E. Mc Sweeney1, P. Hodnett1, J.-A. Shepard2, M.M. Maher1; 1Cork/IE, 2Boston, MA/US (drsemcs@yahoo.com)

Learning Objectives: a) To illustrate with appropriate clinical examples, strate-gies for proper patient and lesion selection, image guidance, techniques of PNBL, specimen handling and post-procedure management. b) To describe common complications associated with PNBL and how to manage them when they occur and steps, which can be taken to avoid these complications.Background: The first CT-guided percutaneous needle biopsy of lung (PNBL) was reported in 1976. Since then results of PNBL have improved with improvements in CT technology and also refinements of needles and other equipment available to the radiologist. The success of percutaneous needle biopsy of lung is now measured by a high rate of diagnostic accuracy and a low rate of complications. A precise, well-planned technique will ensure the highest possible success rate.Procedure Details: The key points in safe and accurate PNBL are careful case selection, immobilization of patient, maintaining quiet reproducible respiration, precise needle alignment in chest wall, single deliberate pleural puncture, clear post-procedure precautions and patient care and expertise in recognition and management of complications.Conclusion: PNBL is a safe and accurate procedure for the diagnosis of focal thoracic lesions. Careful technique with knowledge of pitfalls results in a successful outcome and low complication rates.

C-242 Lung volume quantification in multislice CT using different software tools B. Zudaire, M. Diaz, C. Hernandez, A. Alvarez, G. Bastarrika; Pamplona/ES (bzudaire@unav.es)

Purpose: 1. To compare lung volume measurements using two different software programs. 2. To evaluate reproducibility between readers.Methods and Materials: We obtained 49 data sets from patients from the early lung cancer screening program (ELCAP) who underwent low dose chest CT at deep inspiration. Two radiologists analysed each data set (total lung volume, length and mean lung attenuation) using two different software programs designed for the quantitative analysis of lung volume (Volume and Pulmo). Lung volumes cal-culated by each program were compared using the t student test. Inter-observer reproducibility for lung volume and mean lung density was calculated using the t student test.Results: There were no significant differences in lung volume, length and mean attenuation between the two programs (p 0.01). Inter-observer reproducibility for lung volume and mean lung density was excellent. There were no significant differences between readers (p 0.01). Pulmo had a median operating time seven times greater due to the need for manual correction of lung segmentation and the computer's processing time.Conclusion: Both programs are useful and reproducible software tools for the estimation of lung volume, length and mean lung attenuation. However, Volume is less operator dependent and requires less operating times.

C-243 Effect of image processing in digital chest radiograph on pulmonary nodules detection K. Wang, W. He, Q. He; Beijing/CN (ke7ke@sina.com)

Purpose: To evaluate the effect of multiscale processing in digital chest radiography on pulmonary nodules detection.Methods and Materials: Fifty normal cases and fifty small nodule patient cases (nodule size range, 5-15 mm in diameter; mean, 11 mm) were selected on the basis of confirmation on chest CT. Each case had been taken a chest radiograph obtained with a digital radiography system, and the acquired image was processed by three types of multiscale processing with different structure preference values: (1) default images with the default processing parameter (structure preference 0.0); (2) high-pass images with structure preference 0.4; and (3) low-pass images with structure preference -0.4. Three experienced radiologists independently reviewed the pulmonary nodules detection of three types of processed images, and then recorded the results in consensus. All observations were evaluated by the receiver operating characteristic (ROC) analysis.Results: The mean area under the receiver operating characteristic curve (Az) value

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was 0.739 for default images, 0.697 for high-pass images and 0.789 for low-pass images. There were statistically significant Az values among these three types of processed images (P 0.05). The false-detections of processed images were 43.0% for defalt images, 42.3% for high-pass images and 36.0% for low-pass images.Conclusion: Multiscale processing in digital chest radiography affects the pulmo-nary nodules detection.

C-244 Automated airway measurements in patients with COPD based on CT imagery W. Recheis, A. Foedinger, R. Eder, R. Frank, C.M. Kaehler, D. zur Nedden; Innsbruck/AT (wolfgang.recheis@uibk.ac.at)

Purpose: To evaluate the airway structures from patients with COPD and healthy subjects.Methods and Materials: After informed consent, 15 healthy never smokers (mean age 42 19y) and 12 patients (mean age 57 7y) with COPD (GOLD IV) underwent CT-examination (Siemens Sensation 64, 120 kV, 50 mAs, nativ, soft kernel, 0.5 mm slice thickness) and a pulmonary function test. The CT images were analyzed by specialized software that allows for automated segmentation, skeletonization and measurement of the airway structures which include wall thickness and area, luminal diameter, segment length and branch angles. (Pulmonary Workstation, Vida Diagnostics). The datasets were compared concerning the PWA (Percentage Wall Area = wall area/total cross sectional area), WT (Wall Thickness), ID (Inner Diameter), IDR (Inner Diameter Ratio = min. diameter/ max. diameter) and WTR (Wall Thickness Ratio = min. wall thickness/ max. wall thickness). For the statistical analysis, a Kruskal-Wallis Test was used.Results: Patients with COPD had a significantly lower IDR in 6 (p 0.036) of 27 measured airways. WTR showed ambiguous results in patients with COPD and normal subjects. There was no significant difference in PWA, WT and ID between the two groups. IDR showed a significantly positive correlation with FEV1 in the group "COPD and healthy subjects" (p 0.03).Conclusion: Patients with COPD have a more inhomogenic bronchial lumen shape than healthy subjects in different locations of the bronchial tree. The higher the FEV1, the rounder the bronchial lumen. Remodelling processes might also occur in the larger airways of COPD patients.

C-245 Validation of airway wall volume using micro-CT S. Gupta1, S. Siddiqui1, S.V. Hainsworth1, D. Mawby1, J. Entwisle1, S. McDonald2, P.J. Withers2, C.E. Brightling1; 1Leicester/UK, 2Manchester/UK (drsumitgupta@yahoo.com)

Purpose: In asthma airway wall remodelling is heterogeneous. Volumetric mea-surements of the airway wall will improve our understanding of the relationship between structure and function in asthma. We aimed to validate and optimize the measurement of airway wall volume using Macro-CT by comparison to the ‘gold-standard’ Micro-CT.Methods and Materials: A phantom model of 8 plastic tubes of varying wall volumes (292.7-2655.9 mm3) with their cross-sectional area modeling airway generations 6-12 was constructed. Volumetric measurements were made using stereomicroscopy (SM), Micro-CT and Macro-CT (using Mimics© software). Tubes were thresholded by drawing line profiles across the wall.Results: The intra-class correlation (ICC) between the three methods was excellent (ICC=0.99). The mean (SEM)% error in Macro-CT measurements compared to Micro-CT was 18.1 (3.8)%. An algorithm was derived to minimize error by varying the threshold difference of the wall line profile according to tube size. This reduced the mean (SEM)% error between Macro-CT and Micro-CT to 2.8 (0.7)%.Conclusion: Macro-CT is a reliable and valid method to measure airway volume. The accuracy was optimized using an algorithm based on axial thresholding using Mimics© software.

C-246 CT angiography and 3D post processing in the evaluation of congenital vascular anomalies of the thorax A. Morra1, A. Clemente2, M. Del Borrello1, S. Berretta3, P. Greco1; 1Albignasego/IT, 2Ferrara/IT, 3Catania/IT (aldo.morra@euganeamedica.it)

Purpose: To show cases of rare congenital anomalies of the thoracic vessels evaluated by multidetector computed tomography (MDCT) with special respect to 2D and 3D post-processing.Methods and Materials: Between December 2003 and June 2007, 3500 subjects underwent chest CT, including about 600 in which examinations were made for the

suspect of vascular disease. CT scans were performed using a 16-row MDCT scan-ner (LightSpeed 4X, General Electric Medical System, Milwaukee, WI); the patients evaluated for the suspect of vascular disease were acquired during simultaneous ECG recording. Vascular enhancement was obtained with a bolus of 120-140 ml of low molecular weight non-ionic iodinated (320-350 mgI/ml) contrast agent, injected at 3-5 ml/sec, followed by a saline chaser bolus, via a catheter placed in a cubital vein. The image data sets were processed on two separate workstations (Adwantage Window 4.3, GE; Terarecon Acquarius WS 3.6.2.3), by means to obtain images with several algorithms: Multiplanar Reformatting (MPR), Maximum Intensity Projection (MIP) and 3D Volume Rendering (VR).Results: Different types of anomalies were found: anomalies of the aortic arch: right sided aortic arch; aberrant left subclavian artery (ALSCA); Kommerell’s diverticulum. Anomalies of the descending aorta: aortic coarctation; patent duct arteriosus. Anomalies of pulmonary artery: absence of pulmonary artery; pulmonary sequestration. Anomalies of pulmonary and systemic veins: partial anomalous pulmonary connection; double superior vena cava.Conclusion: MDCT with 2D-3D imaging clearly shows complex vascular congenital anomalies of the chest in non-invasive assessment.

C-247 Computer-aided detection (CAD) in lung cancer screening at chest MDCT: ROC analysis of CAD vs. radiologist performance F. Fraioli, L. Bertoletti, M. Mennini, G. Serra, C. Catalano, R. Passariello; Rome/IT (Francesco.Fraioli@uniroma1.it)

Purpose: Our aim was to compare the performance of radiologists against a CAD algorithm for pulmonary nodule detection on MDCT.Methods and Materials: Three radiologists independently analysed 200 scans and assigned each nodule a confidence score (1-3). CAD was applied to all scans, and successive readers re-evaluated all findings of the CAD, assigning, in consensus, a confidence score (1-3). The reference standard was established by other two expe-rienced chest radiologists. Results were used to generate an FROC analysis.Results: The reference standard showed 124 nodules. Sensitivity for readers I-II-III was: 48, 61, and 36%. A double and triple reading resulted in an increase in sensitivity up to 72%. With CAD, sensitivity was increased to 91, 94, and 92% for readers I, II, and III. The area under the FROC curve (Az) was 0.53, 0.69, 0.42, and 0.80 for readers I, II, III, and the CAD. Differences between all readers and the CAD were significant (P 0.05). For nodules 6 mm Az was 0.72, 0.88, 0.64 and 0.88 for readers I, II, III, and the CAD. P was significant between reader I and the CAD and between reader III and the CAD; it was not significant (P=0.9) between reader II and the CAD. For nodules 6 mm, Az was 0.18, 0.19, and 0.17 for readers I-III and 0.63 for the CAD. Differences between all readers and the CAD were significant (P 0.05).Conclusion: CAD can aid in daily radiological routine detecting a conspicuous number of nodules unseen by radiologists.

C-248 Prospective evaluation of quantitative computed tomography to predict postoperative lung function in patients with pulmonary neoplasm having a lobectomy F. Fraioli, L. Bertoletti, M. Mennini, G. Serra, C. Catalano, R. Passariello; Rome/IT (Francesco.Fraioli@uniroma1.it)

Purpose: To verify the reliability of quantitative 64-detector computed tomography (64-DCT) and to evaluate the postoperative lung function in patients having a lobectomy.Methods and Materials: 25 patients with lung cancer underwent a 64-DCT before having a lobectomy. Pulmonary functional tests were assessed before surgery. Postoperative spirometry was performed two months after surgery. Semi-automatic software was applied to CT scan to calculate the total functional lung parenchyma of the entire lung and of each lobe. Subsequently, a specific equation was used to predict postoperative FEV1 and vital capacity (VC). Predicted values were compared with postoperative measured spirometric values.Results: In 22 patients, there was a significant correlation between estimated VC and measured VC values. Estimated FEV1 was always significantly lower than the corresponding postoperative values. In 3 patients with complications during postop-erative hospital stay no correlation was found. On the basis of pulmonary functional tests, 4 patients were considered to have a borderline pulmonary function. On the basis of estimated FEV1 and VC those patients were considered operable.Conclusion: Quantitative CT evaluation of postoperative lung function may be im-portant especially for those patients with preoperative borderline values. Automated software to calculate total and segmented pulmonary functions and estimated postoperative function is a reliable and simple method that can be applied to all preoperative study as a part of routine chest MDCT examination.

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C-249 Automatic volumetric assessment of pulmonary nodules enhancement: Correlation with axial measurements to evaluate benign and malignant nodules F. Fraioli, M. Mennini, S. Vetere, G. Serra, C. Catalano, R. Passariello; Rome/IT (Francesco.Fraioli@uniroma1.it)

Purpose: To evaluate wash in and wash out densitometric curves of pulmonary nodules (PN) after administration of contrast media, comparing volumetric results with those obtained on a single slice.Methods and Materials: Thirty patients with known PN underwent a dynamic MDCT (Siemens Sensation 64; parameters: 0.6-mm coll., 1-mm interval) before and after the administration of contrast material (c.m). (5-30-60-90, 120 s e 5 minutes). Pathological diagnosis was achieved by surgery in 25 patients and with a follow-up in 5. Sensitivity, specificity and accuracy of malignant nodules was calculated by considering single slice Vs total volume wash in and wash out of c.m. Thirty PN with 18 benign and 12 malignant were included in our analysis. Diagnostic criteria of malignancy included those nodules with a wash in of 25 HU and a wash out less than 30 HU.Results: An almost perfect agreement was obtained between the two measure-ments in the diagnosis of benign nodules while a disagreement occurred in 2 PN histological malignant. In those nodules, a wash in enhancement greater than 25 HU was shown for both measurements but with a wash out respectively greater and smaller than 30 HU when single axial or volumetric assessment were performed.Conclusion: Volumetric assessment of the wash in and wash out curves appears more accurate and reproducible allowing a better evaluation of densitometric curves and reducing limits of single slice evaluation. Moreover, dedicated software may provide a semi automatic analysis with a reduction in the evaluation time and more comparable results.

C-250 Volumetric evaluation of therapy response in patients with lung metastases: Preliminary results with a computer system and comparison with unidimensional measurements F. Fraioli, L. Bertoletti, M. Mennini, S. Vetere, C. Catalano, R. Passariello; Rome/IT (Francesco.Fraioli@uniroma1.it)

Purpose: The assessment of metastatic growth is current performed by RECIST criteria with high inter-observer variability. The aim of this study was to evaluate the role of a dedicated system (LMS lung, Median) with volumetric measurements to assess the response to chemotherapy.Methods and Materials: Forty-two patients were analysed on HRCT protocol in the first and follow-up studies. The indicator lesions were chosen with consensus by two radiologists. Manual unidimensional (the largest diameter) measurements were compared with volumetric measurements automatically provided to evaluate response to chemotherapy per nodule and patient following RECISTc. Our software is provided by a double monitor and enables automatically the evaluation of previous and follow-up study of pulmonary nodules. Axial maximum diameter, volumetric diameter and percentage of nodule modifications by using RECISTc are automati-cally provided by the platform. Interobserver agreement among the two readers and volumetric measurements was assessed by using Cohen K.Results: A total of 148 metastasis in the first and follow-up studies were included in our analysis. Nodule size ranged between 5-34 mm in the first study and 5-41 mm in the follow-up. Results in the response to chemotherapy provided by the observers showed different evaluation in seven patients; agreement between readers in nodule measurement was moderate; agreement between readers on patient’s response to chemotherapy was good. Comparison between volumetric and manual evaluation showed discordant results in 6 cases.Conclusion: The precision of volumetric measurements of pulmonary metastasis has shown to be sufficient high to allow its clinical use in chemotherapy monitoring.

C-251 Evaluation of the cross sectional change of pulmonary peripheral blood flow using CT perfusion J. Nakanishi1, K. Kodani2, Y. Shimatani2, M. Ametani3, T. Ogawa2; 1Tottori-shi/JP, 2Yonago-shi/JP, 3Matue-shi/JP (tenten22@mac.com)

Purpose: The purpose of this study is to assess the cross sectional change of pulmonary peripheral blood flow on the basis of distance from pulmonary surface using perfusion CT.Methods and Materials: Lung perfusion CT images were acquired from 16 normal controls and 12 patients (pulmonary emphysema) using multidetector-row CT. All of the studies were performed after informed consent. Firstly, pulmonary

area (HU -600) and low attenuation area (LAA) (HU -950) were decided. Next, by distance from pulmonary surface, pulmonary area was divided to marginal and central area (pixel rate of each area was 1:1). Finally, in each divided area, LAA rate, blood flow parameters such as peak time (PT) and mean transit time (MTT) by a gamma function model and delayed flow area were calculated, and these values were compared between controls and emphysema group using t-test and Mann-Whitney test.Results: LAA rate was significantly higher in emphysema group than controls (p 0.01). Delayed flow area rate calculated by blood flow parameters was high in marginal area, especially in emphysema group. In emphysema group, delayed PT area rate in central area was significantly higher compared with the whole lung area (p 0.01). This result demonstrated characteristic pulmonary blood flow in emphysema group.Conclusion: We could assess the characteristic cross sectional change of lung perfusion using perfusion CT. This pulmonary segmentation method on the basis of distance from pulmonary surface is useful to analyze peripheral pulmonary blood flow change with morphologic change.

C-252 4-D model of peripheral pulmonary ventilation using synchrotron radiation CT H. Ikura1, K. Shimizu1, M. Ikura1, T. Mochizuki2, T. Nagareda3, Y. Imai1; 1Tokyo/JP, 2Ehime/JP, 3Hyogo/JP (mihoyoshikawa@yahoo.co.jp)

Purpose: We propose a new simulation technique of air flow in three-dimensional space (4-D modeling) of the peripheral lung at microscopic view using the isotropic volume data of normal and diseased lung obtained with synchrotron radiation CT (SRCT).Methods and Materials: Lung specimens with pulmonary fibrosis, emphysema and no pulmonary disease were obtained at autopsy and were inflated and fixed. SRCT images of the specimens were obtained with the SRCT system (SPring-8, Hyogo, Japan). The isotropic volume data with 12-μm of voxel size were provided, as stacked with 815 axial images of SRCT. 3-D microstructures were obtained with automatic segmentation and combination of the surface and volume rendering display technique. For 4-D modeling of the peripheral air flow, each point within the peripheral airspace was assigned two values, distance from start point and nearest airspace boundary. With these assigned values, the 4-D model of air flow was demonstrated as animations.Results: 4-D modeling of the peripheral air flow and diffusion could represent well the normal peripheral ventilation. In pulmonary fibrosis, the peripheral volume of airspace and filling time into peripheral airspace beyond respiratory bronchiole was decreased compared with normal model. On the other hand, in emphysema, the volume and filling time was increased compared with the normal model. In both pathologic models, the difference of peripheral ventilation could be demonstrated clearly compared with the normal model.Conclusion: 4-D modeling using the data obtained with SRCT could simulate the air flow in the peripheral lung at microscopic view.

C-253 Radiofrequency ablation and cryotherapy for inoperable pulmonary lung malignancy G.-Y. Jin, Y. Lee, Y. Choi, Y. Han; Jeon-ju/KR (gyjin@chonbuk.ac.kr)

Purpose: To investigate effects of percutaneous thoracic cryotherapy (PTC) and ra-diofrequency ablation (RFA) on clinical courses of pulmonary malignant tumors.Methods and Materials: Seventy-one patients with lung malignancy underwent RFA or PTC. They were considered not to be surgical candidates because of advanced or metastatic diseases, poor physiologic reserve, or patient refusal. We evaluated the results of RFA and PTC including efficacies, local progression rate, survival rate, and complications.Results: Thirty-two patients (44.4%) treated with RFA and six patients (60.0%) with PTC attained complete ablation. In small sized lung mass ( 3 cm), complete ablation rate of RFA and PTC was increased to 77.3 and 85.7%, respectively. Additionally, we have found that complete ablation group had significantly higher survival duration and progression free survival duration compared with partial ablation group. Moreover, the complication profile was acceptable and the pain associated with the procedures disappeared within 1 day, 46 patients (63.9%) after RFA and all patients after PTC.Conclusion: PTC and RFA may be very useful as treatment alternatives with low procedural morbidity in the managements of inoperable pulmonary malignant tumors.

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C-254 Is there an increased risk for pneumothorax when performing CT-guided lung punctures in patients with diffuse lung disease? M. Lönnemark, P. Örneholm, K. Lamberg, A. Magnusson; Uppsala/SE (maria.lonnemark@radiol.uu.se)

Purpose: Many patients who are subjects for puncture of a focal lung lesion have coexisting diffuse lung disease. The aim of this study was to investigate if there was an increased risk of pneumothorax when biopsing these patients. We also investigated if the pneumothoraces in this group required treatment and hospitali-sation to a higher degree.Methods and Materials: 199 patients were included. 70 patients had coexist-ing lung disease; obstructive lung disease/emphysema (n=51), restrictive lung disease/fibrosis (n=7) or pleural plaque/diffuse tumour infiltration of the thoracic wall (n=21). All procedures were performed with an 18-G cutting needle through a 17-G introducing needle. Control CT scanning was performed 5 minutes post procedure and a chest X-ray was performed after 4 hours. The presence and grade of pneumothorax was recorded as well as the need for drainage.Results: Pneumothorax occurred in 41% of the normal group and in 47% of the patients with obstructive or restrictive lung disease. No significant difference was found between the groups. Most pneumothoraces in both groups were small and there was no significant difference between the groups regarding the need for drain-age at 8% and 15% of the pneumotharaces, respectively. In patients with pleural plaques or tumour infiltration of the thoracic wall the frequency of pneumothorax was significantly lower, 5%.Conclusion: During CT-guided lung biopsies patients with coexisting lung disease do not run a higher risk of pneumothorax than normal patients. The grade and the need for treatment are equal for both groups.

C-255 Quantitative assessment of airway dimension for pulmonary disease: Development of dedicated software for multi-detector CT S. Choi1, Y. Kim1, H. Seon1, N. Chang2, J. Kim1, J. Park1, H. Kang1; 1Kwangju/KR, 2Chollanamdo/KR (songchoi@cnuh.com)

Purpose: To design and prospectively validate the ability of dedicated three dimensional software tool to measure central airway dimension on multi-detector row CT (MDCT) images in a porcine model.Methods and Materials: With Delphi 7.0 software, we programmed new dedicated software for measuring the central airway dimension on MDCT images. Software was validated in volumetric MDCT data set obtained with fifteen pigs. All obtained images were transferred via PACS to a personal computer for quantitative analysis of airway dimension such as lumen area (LA) and wall area (WA). Immediately after CT scanning, all porcine lungs including trachea were removed from freshly sacrificed pigs and were fixed in inflation with formalin fume. They are cut into 1 cm-thick transverse slices perpendicular to their running axis, in a plane similar to that which is used with software, and their airway dimensions were evaluated with graphic analysis software. Airway dimensions obtained with the dedicated software were compared with those obtained with excised lung sample by means of the Wilcoxon sign rank test and Bland-Altman analysis.Results: Airway dimensions obtained with the dedicated software were not signifi-cantly different from those assess from excised lung sample (p .05). For LA and WA, strong corelation was found for both measurements (p .01).Conclusion: Dedicated three dimensional software tool to measure central airway dimension is able to be accurate and reproduce measurement of WA and LA on reformatted MDCT dataset.

C-256 Dual energy computed tomography (DECT) of the chest for differentiation of iodine and gadolinium enhanced artificial pulmonary nodules N. Knöss, H. Bolte, B. Hoffmann, M. Heller, J. Biederer; Kiel/DE (naomi.knoess@rad.uni-kiel.de)

Purpose: To develop a suitable ex-vivo method for assessing the potential of Dual Energy Computed Tomography (DECT) of the chest for the detection of iodine contrast enhancement in pulmonary nodules for evaluation of the dignity of the lesion.Methods and Materials: Five artificial iodine and five gadolinium enhanced nodules (mean maximum diameter 0.7-1.4 cm) were introduced into a porcine lung explant that was inflated inside a chest phantom. This set-up was scanned with a dual source CT scanner with two X-ray tube-detector systems operated simultaneously at 80 kV and 140 kV, respectively. To simulate the density of non-iodine containing pulmonary nodules, we chose gadolinium because of its small increase of attenu-ation at 80 kV, similar to that of soft tissue.

Results: Mean CT values of iodine-enhanced nodules increased from 153.1 Houn-sfield Units (HU) to 304.5 HU at 140 kV and 80 kV, respectively. CT numbers of gadolinium enhanced nodules increased from 43.6 HU to 76.6 HU. Postprocessing produced virtually non-enhanced images after subtraction of contrast agent related elevation of density, revealing the fatty and agarose matrices of the artificial nodules, as well as images with colour highlighting of the iodine enhanced nodules.Conclusion: The results of this ex-vivo study confirm the principal feasibility of differentiating solid pulmonary lesions by their iodine uptake and tissue properties with a single DECT scan. The presented experimental set-up appears promising to investigate further open issues such as the influence of iodine concentration, lesion size and radiation exposure.

C-257 Reproducibility of hemodynamic parameter quantification in lung tumors using dynamic CT U. Haberland1, A. Abramyuk2, E. Klotz1, N.D. Abolmaali2; 1Forchheim/DE, 2Dresden/DE (ernst.klotz@siemens.com)

Purpose: To quantify the interobserver variability of the quantification of blood circulation in non small cell lung cancers (NSCLC).Methods and Materials: 18 Patients with proven NSCLC underwent 60 s dynamic contrast-enhanced CT measurement (Biograph 16, Siemens) following intravenous contrast administration (100 ml@4.5 ml/s, Ultravist®-370, Bayer). CT data were ac-quired prior to radiotherapy. Tumor blood volume (BV) and volume transfer constant (ktrans) were independently determined by two observers with prototype perfusion software. Reproducibility was calculated by the Bland-Altman statistic.Results: Absolute values of BV and ktrans were 7.4 3.4 ml/100 ml and 19.9 7.1 ml/100 ml/min, respectively. Both BV and ktrans showed good agreement between the two observers. The mean difference (95% limits of agreement) was 0.2 (-1.9, 2.3) ml/100 ml for BV and -0.1 (-4.7, 4.5) ml/100 ml/min for ktrans with a variability of 1.1 ml/100 ml and 2.4 ml/100 ml/min. This corresponds to variation coefficients for BV and ktrans of 14.4% and 11.8%, respectively.Conclusion: Our data supports the reliability of dynamic contrast-enhanced CT measurement for the quantification of blood circulation in lung tumors. Quantitative values are reproducible in patients.

C-258 Dual source CT angiography in patients with acute chest pain M. Arraiza, G. Bastarrika, J.C. Pueyo, B. Zudaire, A. Alonso-Burgos, A.J. Villanueva; Pamplona/ES (marraizasa@unav.es)

Purpose: Aortic dissection, pulmonary embolism, and myocardial infarction are the most relevant causes of acute chest pain. The purpose of this study was to assess the diagnostic value of dual-source CT (DSCT) as a technique to simultaneously evaluate pulmonary vessels, aorta and coronary arteries.Methods and Materials: This study included forty-nine subjects (29 male, 20 female, mean age 55.65 16.23 years) with acute chest pain who underwent ECG-gated DSCT. No beta-blockers were administered prior to the exam. Studies were performed after intravenous injection of 120 ml of iodinated contrast material at 4 ml/s flow rate followed by 50 ml of saline flush using the bolus tracking technique. Studies were analyzed by two independent observers blinded to the results. Imaging findings were correlated with clinical history and laboratory tests. Clinical follow-up of all subjects was performed.Results: Good interobserver agreement was observed. In 24 patients, DSCT exams revealed vascular disease: pulmonary embolism (5), aortic aneurysm (2), aortic ulcer (1), and coronary artery disease (16). Of the latter, six were coronary anomalies, three patients had significant and seven subjects had non-significant coronary stenosis (7). Additional diagnoses were pneumonia (13), lung cancer (1) and sarcoidosis (1). Normal DSCT was found in the remaining. Results correlated well with clinical findings.Conclusion: DSCT is a valuable technique for the accurate diagnosis of the cause of chest pain of clinically uncertain etiology as it allows assessing pathology involving main thoracic vessels and pulmonary disease in a single breath hold.

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C-259 The utility of radiographic vascular pedicle measurements in assessing the hemodynamic status of patients who recently underwent coronary artery bypass graft surgery V. Tatco, A. Villarosa; Quezon City/PH

Background: The role of portable, anteroposterior, supine chest radiographs (CXRs) in evaluating the hemodynamic status of post-surgical cardiac patients is controversial.Methods and Materials: We retrospectively evaluated such CXRs in 162 recent post-coronary artery bypass grafting (CABG) patients with pulmonary artery catheters. Three radiologists independently reviewed the CXRs without clinical and hemodynamic information and recorded the Vascular Pedicle Width (VPW) and Vascular Pedicle-Thoracic (VT) ratio. The averages of the three radiologists’ measurements were computed and were correlated with pulmonary capillary wedge pressure (PCWP).Results: Overall mean ( SD) VPW and VT ratio are 7.1 0.7 cm and 0.25 0.02, respectively. Of the 162 patients, 96 (59%) had low-to-normal PCWP (18 mmHg). The low-to-normal PCWP and high PCWP groups had mean VPW of 6.9 0.7 cm and 7.3 0.6 cm, respectively (p=0.000). The mean VT ratio of the low-to-normal PCWP group was 0.24 0.02 while that of the high PCWP group was 0.27 0.02 (p = 0.000). VPW and PCWP showed weak correlation (r=0.257) whereas VT ratio and PCWP showed good correlation (r=0.620). Optimal cut-off points in differentiating low-to-normal and high PCWP for VPW and VT ratio are 7.0 cm (sensitivity=77.3%; specificity=51.0%; p=0.000) and 0.26 (sensitivity=89.4%; specificity=87.5%; p=0.000), respectively.Conclusion: Radiologic assessment of the vascular pedicle adds clinically useful dimension to CXRs in the evaluation of hemodynamic status of cardiac patients.

C-260 Pitfalls and artefacts in CT pulmonary angiography D.P. Deva, I. Britton, N.A. Watson; Stoke-on-Trent/UK (dpdeva@hotmail.com)

Learning Objectives: To illustrate examples of both common and unusual pitfalls in the interpretation of CT pulmonary angiography.Background: CT pulmonary angiography is now the first line investigation in the diagnosis of acute pulmonary embolism in many hospitals and has replaced isotope studies and invasive pulmonary angiography. Despite the new technology there are still pitfalls within the imaging technique and it is essential for the radiologist to be aware of these when reporting CTPA scans for potential pulmonary embolism.Imaging Findings: Examples of appearances mimicking pulmonary embolism including artefacts caused by technical factors including cardiac motion, beam hardening effects, and contrast timing as well as anatomical and pathological ap-pearances such as inter-segmental lymph nodes, aberrant vessels, tumour invasion, device artefact, post-surgical change, and congenital heart disease are illustrated. Artefacts are presented alongside examples of pathology that they mimic. Methods of confirming the artefacts are discussed and illustrated.Conclusion: Various artefacts may mimic pulmonary emboli and aortic disease. The radiologist needs to know of their existence and the imaging features that differentiate them from true pathology.

C-261 Heart and great vessels: From chest radiograph to multislice CT D. Varona Porres, R. Mitjana, R. Monmany, J. Cáceres, C. Simón, M. Simonet; Barcelona/ES (dvarona69@hotmail.com)

Learning Objectives: 1) To show the usefulness of certain imaging techniques for examining the heart and great vessels. 2) To illustrate diseases affecting the heart and great vessels by chest radiography and multislice CT. 3) To correlate chest radiography findings with those of multislice CT.Background: Chest radiography is the first technique used to assess the heart and great vessels. Multislice CT findings can correlate closely with those of chest radio-graphs, particularly when reformatting techniques are used (MPR, MIP or 3D).Procedure Details: The exhibit is structured in three main parts: normal anatomy, heart disease and great vessel disease. Chest radiography allows easy evaluation of the normal anatomy of the cardiovascular system and multislice CT can help in the interpretation. Diseases of the heart and great vessels are first evaluated with chest radiography, which can determine the size of the entire heart and individual chambers, great vessels size, presence of cardiovascular calcifications, and status

of the pulmonary vascularization. Specific diseases can be diagnosed with multislice CT: e.g., cardiac tumors, pericardial effusion, aneurysms, aortic dissection and pulmonary embolism. These conditions are illustrated, with special dedication to the correlation between chest radiography and multislice CT.Conclusion: Chest radiography is a useful, low-cost imaging technique for examin-ing the heart and great vessels, but extensive training is needed for the interpreta-tion. Multislice CT findings correlate closely with the chest radiograph and specific diagnoses can be established.

C-262 Partial anomolous pulmonary venous drainage: A review of CT images R. Summerfield, D.P. Deva, M. Goldstein, M. Metelko, N.A. Watson; Stoke-on-Trent/UK (summerstuff@yahoo.com)

Learning Objectives: To review the normal anatomy of the pulmonary veins and to present examples from CT scans of the common variants of partial anomalous pulmonary venous return.Background: The number of CT scans performed by radiology departments is increasing as technology evolves and demand increases. We are therefore seeing increasing numbers of congenital anomalies. With the advent of multislice CT and multiplanar reformats, these can be visualised in three planes. Partial anomalous pulmonary venous return represents a spectrum of important congenital anoma-lies. Whilst their clinical significance varies, they represent an important ‘incidental finding’ on CT.Imaging Findings: We present a series of several examples of partial anomalous pulmonary venous drainage diagnosed at our centre. These include examples of right-sided supracardiac and infracardiac (simitar syndrome) veins and the less common left-sided anomalous veins.Conclusion: As the number of chest CT scans performed grows, increasing num-bers of variations of pulmonary vasculature will be found. Radiologists need to be able to recognise and characterise these important congenital anomalies.

C-263 Spectrum of cardiovascular pathologies demonstrated by dual source CT angiography of the chest T. Heye, G. Richter, S. Ley, M. Schlieter, G. Szabo, G.W. Kauffmann, W. Hosch; Heidelberg/DE (tobias.heye@med.uni-heidelberg.de)

Learning Objectives: To demonstrate a broad spectrum of cardiovascular patholo-gies of the chest by ECG-gated dual source CT angiography of the chest.Background: ECG-gated dual source CT of the chest or the so-called “triple rule out” protocol is a combination of an ECG-gated dual source CT angiography of the heart with additional scanning of the thorax and cranially of the heart. This combined technique is incorporated in one scanning protocol to assess coronary arteries, heart valves and ventricular volumetry, in combination with the rest of the thorax in one scan with submillimeter resolution and a high temporal resolution.Imaging Findings: Cardiovascular pathologies of the coronaries (stenosis, stent, Kawasaki-syndrome), heart valves (stenosis, insufficiency, artificial replacement of the mitral and aortic valve), the myocardium (scar tissue of myocardial infarction, ventricular wall pathologies, cardiac cystic echinococcosis) and the thoracic aorta (aneurysm, aortic dissection, floating thrombus) are demonstrated by 2D, 3D and 4D reconstructions. Complications and postoperative status of cardiothoracic sur-gery (CABG, LVAD, post sternotomy complications) as well as vascular anomalies (persistent superior left vena cava, TGA) are illustrated.Conclusion: Modern multislice CT angiography of the chest, especially dual source CT angiography provides a high spatial and temporal resolution to identify a broad spectrum of common and uncommon cardiovascular pathologies or postoperative changes of the chest. The essential advantage of this modality in the clinical routine is its non-invasive character and the ability to deliver a morphologic and functional evaluation of the heart and the thorax in a “one-stop-shopping” study.

C-264 Radiological monitoring in pulmonary embolism with 64-multidetector CT G. Gallardo-Madueño, I. Torres, C. Fernandez-Capitán, A. Lorenzo, E. Alonso; Madrid/ES (ggallar@gmail.com)

Purpose: The purpose of our study was to evaluate 64-multidetector CT pulmonary angiography (MDCTA) as a primary tool both in diagnosis and follow-up in pulmonary embolism (PE), with focus on chronic embolism at 6-months control.Methods and Materials: 157 patients with high clinical suspicion of acute PE under-went MDCTA (Aquillion 64, Toshiba Medical Systems®). Patients with radiologically confirmed PE also underwent MDCTA at six months to determine treatment inter-ruption and evolution to chronic PE and pulmonary hypertension. Two independent

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radiologists reviewed all MDCTA studies. CT signs of acute or chronic PE at the level of the central and peripheral pulmonary arteries were recorded.Results: Prevalence of acute PE was 30.7% (n=48) in initial scan, while MDCTA was negative in 59.23% (n= 93). Four patients (8.3%) have only subsegmental PE. After at least 6 months of treatment, 83.3% (n=40) revealed absence of endolumi-nal clots and 17% (n=8) patients showed images of persisting thrombi. However 12.5% of the patients with resolution of the clot had signs of severe pulmonary hypertension. There was no correlation between the radiological severity of the PE at diagnosis and the resolution of the clot.Conclusion: 64-multidetector CTPA yields a high rate of diagnostic scans, allowing good evaluation of central and peripheral pulmonary vasculature. 6-months follow-up MDCTA plays an important role, giving information about chronic PE and pulmonary hypertension that can dramatically change patients’ prognosis.

C-265 Comparison of two clinical prediction rules for suspected pulmonary embolism using multidetector computed tomography (MDCT) and CT venography I.R. Ozkan, C. Calisir, U.S. Yavas, F. Alatas, I.A. Cevik; Eskisehir/TR (cuneytcalisir_72@yahoo.com)

Purpose: The aim of the study is to compare two scoring methods for patients with suspected pulmonary embolism (PE) using computed tomography angiography (CTA) combined with CT venography (CTV) as diagnostic criteria.Methods and Materials: Patients with diagnostic CTA or positive CTV were included in the study. Patients were categorized into one of three probabilities based on Wells and Revised Geneva scores. CT scanning was performed with a multidetector CT scanner. Identification of embolism by CTA or deep vein thrombosis by CTV was sufficient for PE diagnosis.Results: Among 167 consecutive patients who underwent CTA and CTV, 148 patients with diagnostic CTA or positive CTV were included in the study. PE was identified in 48 out of 148 cases. When the cases were examined with clinical prob-ability methods, the percentages of patients diagnosed with PE in high, moderate, and low probability groups determined by Wells and revised by Geneva methods were 89.6% and 83.3%, 26.4% and 25.6%, and 7.8% and 0%, respectively. When two clinical probability scores were compared, kappa analysis revealed a low level of agreement between two scoring systems. When the values of two scoring methods in establishing PE diagnosis were compared with the ROC curve, among inpatients and emergency department patients, there was statistically significant difference between the areas under the curve.Conclusion: The results clearly show that revised Geneva scoring system can be used in emergency department patients with high reliability. The Wells rule appears to be more accurate among both inpatients and emergency department patients.

C-266 Evaluation of MDCT angiography and venography in pulmonary embolism J. Pamies Guilabert, P. Braun; Valencia/ES (pamies_jos@gva.es)

Purpose: The purpose of this study is to determine whether multidetector computed tomography (MDCT) pulmonary angiography and lower extremity venography negative for pulmonary embolism is a sufficiently reliable criterion to safely with-hold anticoagulation therapy.Methods and Materials: We studied prospectively 383 consecutive patients (211 female, 172 male, mean age: 72 years, age range: 17-94 years) with suspicion of acute pulmonary embolism by means of 10-MDCT. Additionally, ventilation-perfusion scintigraphy and lower extremity sonography were performed. The patients with negative CT and without anticoagulation therapy underwent a 6-month follow-up to exclude recurrent pulmonary embolism or venous thrombosis.Results: 156 patients had a positive CT (pulmonary embolism, venous thrombosis or both), 224 patients a negative CT and 3 were inconclusive. 5 patients with a nega-tive MDCT showed high-probability scintigrams and 2 patients had a deep venous thrombosis on lower extremity sonography. Besides, during the 6-month follow-up, one patient died probably due to recurrent pulmonary embolism. The negative predictive value for MDCT pulmonary angiography and venography was 96%.Conclusion: MDCT pulmonary angiography and venography is a reliable imag-ing tool for excluding pulmonary embolism. The negative predictive value of this technique, 94-100% in literature, is very high. Therefore, it is safe to withhold anticoagulation therapy in patients with suspicion of pulmonary embolism in case of a negative MDCT, even without performing other diagnostic tests.

C-267 Utility of MDCT in identification of the hypertrophied bronchial artery causing hemoptysis: Correlation with bronchial angiography J.-Y. Rho, S.-J. Lee, M.-D. Kim, J.-Y. Jung, Y.-K. Lee; Seongnam/KR (rhoji@naver.com)

Purpose: To evaluate the utility of MDCT in identification of the hypertrophied bronchial artery causing hemoptysis.Methods and Materials: We retrospectively reviewed the cases of all patients with hemoptysis who had presented at out hospital between March 2006 and September 2007 and had undergone 16-MDCT and bronchial artery embolization. MDCT scans including axial image (5 mm interval), coronal reconstruction image (3 mm thickness, 3 mm increment) were evaluated by one radiologist. MDCT findings were compared with those of bronchial angiography. The sensitivity and specificity of MDCT for predicting the presence of hypertrophied bronchial arteries were assessed.Results: 20 patients meeting the inclusion criteria were identified. There were 9 men and 11 women, with an average age of 52.2 years (18~78 years). Clinicora-diographically determined diagnoses of their symptoms were active tuberculosis (n=6), sequelae of tuberculosis (n=4), unknown (n=4), bronchiectasis (n=3), aspergilloma (n=2), and nontuberculous mycobacterial infection (n=1). 25 hypertro-phied bronchial arteries were identified at MDCT and/or angiography. In 17 cases, concordant findings were observed with both modalities. In 8 cases, MDCT could not be used to detect the hypertrophied bronchial arteries. Coronal reconstruction images were found to the superior to axial images in depicting the hypertrophied bronchial arteries. In the determination of hypertrophied bronchial arteries, MDCT had a sensitivity 68% and specificity 100%.Conclusion: MDCT demonstrates acceptable sensitivity, specificity in the prediction of hypertrophied bronchial arteries in patients with hemoptysis. MDCT can depict and trace the hypertrophied bronchial arteries and, in most cases, can be used to detect the hypertrophied bronchial arteries causing hemoptysis.

C-268 Quick and effective assessment of right ventricular dysfunction in the course of acute pulmonary embolism assessed with multislice computed tomography G.J. Staskiewicz, E. Czekajska-Chehab, J. Przegalinski, A. Tomaszewski, I. Wegrzyn-Szkutnik, K. Torres, A. Torres, R. Maciejewski, A. Drop; Lublin/PL (grzegorz.staskiewicz@am.lublin.pl)

Purpose: Right ventricular dysfunction (RVD) is a severe complication of acute pulmonary embolism (PE). The aim of the study was to evaluate usefulness of MSCT pulmonary angiography (MSCTPA) in the assessment of RVD in patients with acute PE.Methods and Materials: 50 patients with acute PE confirmed with MSCTPA (8- and 64-row scanners) were included. Quantification of pulmonary obstruction was performed according to Miller et al., Qanadli et al. and Mastora et al. All patients had echocardiographic examination with measurement of pulmonary artery systolic pressure (PASP) performed. Dimensions of right and left ventricles and diameters of ascending aorta (Ao), pulmonary artery (PA), superior vena cava (SVC), inferior vena cava (IVC) and azygos vein (AV) were measured.Results: Pulmonary obstruction scores according to all three methods were significantly higher in group with increased PASP than in patients with normal pulmonary pressure. PA, Ao, SVC and AV diameter were significantly higher in patients with increased PASP. The highest sensitivity for presence of increased PASP was observed for PA 32 mm (73%) and SVC 25 mm (74%), and specific-ity for AV 10 mm (86%).Conclusion: The used parameters allow a reliable evaluation of severity of pulmonary obstruction in patients with PE. High values of obstruction scores, accompanied by increased diameters of mediastinal vessels, objectively indicate RVD in patients with acute PE.

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C-269 A web-based, interactive tutorial and reference database in anatomy for chest imaging R. Talanow1, H.-H. Jend2; 1Cleveland, OH/US, 2Bremen/DE (roland@talanow.info)

Learning Objectives: To create a comprehensive learning tool and a quick refer-ence for beginning radiology residents and radiologically less experienced clinicians to become familiar with physiologic and pathologic findings in chest imaging.Background: Especially for junior radiology residents and radiologically less expe-rienced physicians, it can be difficult to differentiate between physiological thoracic structures and normal variants from pathological findings on plain film and CT. An interactive, step-by-step tutorial showing and explaining physiology and pathology in chest imaging is desirable.Procedure Details: This online chest tutorial consists of over 150 pages and over 80 images covering plain film and computed tomography. Chapters offer learning material about techniques, standard exams, projections, airways, lung parenchyma, heart and vessels, mediastinum, diaphragm, pleura, pitfalls, pathology and normal values. Interactive annotations enhance the learning experience. Pre- and post tests evaluate the learning progress. Freetext search and predefined menus allow individual display of contents.Conclusion: The authors present an interactive tutorial which serves beginning radiology residents and radiologically less experienced clinicians as a compre-hensive learning tool as well as a quick reference to get familiar with physiologic and pathologic findings in chest imaging. Free online access makes it constantly and quickly available and interactivity helps to accommodate the user’s needs to enhance the learning experience.

C-270 A web-based, interactive tutorial and reference database in thoracic tumor imaging R. Talanow1, H.-H. Jend2; 1Cleveland, OH/US, 2Bremen/DE (roland@talanow.info)

Learning Objectives: To create a comprehensive learning tool and a quick refer-ence for junior radiology residents and radiologically less experienced clinicians to differentiate benign from malignant findings in chest imaging.Background: It can be difficult particularly for radiology residents and less ex-perienced radiologists who are not specialized in chest radiology to differentiate benign from malignant findings in chest imaging. An interactive, step-by-step tuto-rial to train and refresh knowledge about benign and malignant findings in chest imaging is desirable.Procedure Details: This online chest tutorial consists of over 150 pages and over 330 images covering plain film, CT, MRI, angiography, nuclear medicine and pathol-ogy. Chapters offer learning material about tumor appearance, location, SPN/mass, carcinoid, adeno-CA, SCC, other and pseudotumors, development of metastases, TNM, and therapy induced pattern. Staging tools enhance the learning experience. Pre- and post-tests evaluate the learning progress. Freetext search and predefined menus allow individual display of contents.Conclusion: We present an interactive tutorial which serves radiology residents and less experienced radiologists as a comprehensive learning tool as well as a quick reference to differentiate benign from malignant findings in chest imaging. Automatic staging tools help making staging of common chest malignancies easy and accurate. Free online access and interactive features which are constantly and quickly available enhances the learning experience for the user.

C-271 Retracing the path: From MDCT to the chest X-ray J. Palmer, J. Roldan, C. Reynés, M. Rodriguez, G. Sempere, J. Pueyo; Palma de Mallorca/ES (jpalmer@ono.com)

Learning Objectives: To give radiology residents renewed enthusiasm for inter-preting chest radiography, using the ability of the MDCT scanners to obtain images of use in their training.Background: Chest radiography remains the mainstay for diagnosis of many pulmonary diseases. In most instances, it is the first, and frequently the only, imaging test performed in patients known to have or suspected of having a tho-racic abnormality. Despite this fact, academic medical centers, by emphasizing high-technology imaging modalities, notably MDCT and MRI, fail to train radiology residents in the plain film evaluation.

Procedure Details: AIP (average intensity projection) post-process image manipu-lation is used to obtain coronal and sagittal images, of different section thicknesses, targeting thoracic structures of interest. Progressive augmentation of the thickness of the AIP image leads to images whose appearance is similar to that of conventional chest radiography. We review the radiological anatomy and pathological alterations presenting case examples: the mediastinum (contour, lines, stripes and mediastinal masses), thoracic aorta and pulmonary hilae (vascular alterations and hilar masses), the heart (cardiac borders and growth in cardiac chambers in heart diseases), lung masses, atelectasia, alveolar consolidation and the thoracic cage.Conclusion: When we review the thoracic and cardiac studies on the MDCT scan console, utilising AIP reconstruction, we can easily obtain images similar to those of conventional chest X-rays. This simple trick is of great assistance to residents in learning to interpret conventional chest X-rays, and in understanding how the images are formed, at the same time as they are training in the analysis of MDCT studies.

C-272 A pictorial review of “signs in thoracic imaging” K. Karuppasamy1, J. Curtis2, M. Abhyankar-Gupta2, H. Fewins2; 1Chester/UK, 2Liverpool/UK (karnavel@gmail.com)

Learning Objectives: To provide an educational tool for the viewers in the form of an exhibit to demonstrate the presence of several signs in thoracic imaging. To understand these signs and use that knowledge later in practice while reporting.Background: Signs in radiology represent characteristic descriptive patterns of certain abnormalities. There are several such signs commonly associated with thoracic imaging. Clear understanding of what these signs mean helps the radiolo-gists to interpret the images more effectively, provide a more precise prediction of an underlying pathology and avoid using lengthy descriptions. This pictorial review would help the viewer to learn about the presence of such signs, understand what they stand for and register the images of those signs in their minds.Imaging Findings: We illustrate thirty signs encountered in thoracic imaging: air bronchogram sign, air crescent sign, bulging fissure sign, comet tail sign, continu-ous diaphragm sign, crazy paving sign, CT angiogram sign, CT halo sign, deep sulcus sign, double density sign, fallen lung sign, figure 3 sign, fissure sign, flat-waist sign, Fleischner sign, gloved finger sign, golden.s. sign, Hampton hump sign, headcheese sign, Hilar overlay sign, Luftsichel sign, positive bronchus sign, ring around the artery sign, scimitar sign, signet ring sign, silhouette sign, split pleura sign, thymic sail sign, tree-in-bud sign, and Westermark sign. We have used images from appropriate imaging modalities to demonstrate the signs.Conclusion: We believe that this pictorial review with description will help the view-ers to remember and recall the signs appropriately during their practice.

C-273 Imaging findings of mediastinal masses with pathologic correlation: A pictorical review C. Andreu, B. Lopez-Botet, M. Manzano, M. Olivera, P. Caballero; Madrid/ES (carlotaandreuarasa@yahoo.com)

Learning Objectives: 1. To illustrate the anatomical mediastinal compartments seen on plain films. To describe classic signs that allow recognition of mediastinal pathology in conventional radiology. 2. To present radiological findings of mediastinal processes by conventional chest radiography and cross-sectional imaging.Background: The lack of contrast between the different mediastinal structures in conventional radiography makes dificult mediastinal processes diagnosis. Nevertheless, the PA and lateral chest radiograph may be very useful as the initial examination to detect mediastinal masses differentiating them from pulmonary lesions and suggesting its localization and density. Analize of mediastinum starts with a deep knowledge of radiologic anatomy and semiology.Imaging Findings: We review masses localized in mediastinum, diagnosed dur-ing the last five years in our center, from the data base of La Princesa Hospital of Madrid. The process has been performed through the analysis of simple chest radiographies by two senior radiologists and the classification, in accordance with classic semeiology, in the different medistinal compartments. Then, CT allowed to make precise its location and nature. Histologic examination after biopsy or surgery was performed in all the cases.Conclusion: Anatomical and classic semiology knowledge is good bases to local-ized mediastinal masses in convencional radiology. This poster presents the vast spectrum of radiological features of mediastinal masses, checking over each of their possible anatomical setting and their radiological findings.

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C-274 The many faces of pleural disease M. França1, J. Pires1, M. Certo1, J. Calatayude2, D. Castellon2, P. Varzim1, M. Ribeiro1; 1Porto/PT, 2Vigo/ES (mariamanuela.franca@gmail.com)

Learning Objectives: To review the many findings of pleural disorders in imaging techniques, focusing on radiographs and computed tomography (CT), identifying those findings that may help to reach a specific diagnosis.Background: The pleura can be affected for disorders with diverse etiologies. Chest radiography is usually the first technique for detecting most pleural abnor-malities. However, other imaging modalities, especially CT, may be used to confirm the presence, to characterize, and to evaluate the extent of a pleural lesion. Also, some CT findings can help to differentiate benign from malignant pleural disease. However, radiology cannot always provide a specific diagnosis, and histopathologic evaluations may be required.Imaging Findings: The authors review the many findings observed in radiographic and CT evaluation of patients with pleural disease, exemplifying with representative cases. The chest radiographs and CT findings that usually suggest a pleural lesion are: lenticular shape; obtuse angle at the chest wall interface; well defined margin with the adjacent lung. Some CT findings, like fat content, calcifications, extra-pleural fat thickening, and water density of loculated effusions, may help differentiate benign from potentially malignant pleural disease. The intravenous contrast administration is not always required. However, it is important to identify empyemas peripheral enhancement, to differentiate atelectasis and consolidation from pleural fluid, and to identify enhancing pleural nodules as a cause for pleural effusion.Conclusion: Imaging findings can identify the presence and extent of pleural disorder. And, although a histopathologic evaluation may be required, they may allow presuming a specific diagnosis for pleural disease.

C-275 Blunt chest trauma: Spectrum of findings with emphasis on MDCT S.K. Lapsia, M. Goldstein, R. Davis, M. Bydder; Stoke-on-Trent/UK (jlapsia@hotmail.com)

Learning Objectives: To illustrate the imaging findings, with particular emphasis on multidetector computed tomography (MDCT), encountered in blunt chest trauma.Background: Chest injuries account for a significant proportion of mortality and morbidity in trauma patients. Radiologists play a central role in the diagnosis of injuries allowing patients to be treated appropriately. The chest radiograph is a valuable investigation but has been superseded by MDCT, and the latter is now the optimum investigation in the haemodynamically stable trauma patient.Imaging Findings: This educational exhibit uses a variety of imaging modalities with particular emphasis on MDCT to illustrate characteristic findings encountered following blunt chest trauma. Injuries to the great vessels and pulmonary system, as well as skeletal and diaphragmatic injuries are depicted. A few rare injuries are also demonstrated. The importance of multiplanar reconstructions is highlighted to help increase diagnostic confidence. Furthermore the value of maximum intensity projections (MIP) and 3-D display techniques are emphasised. Important radiological signs are referenced with current literature to provide a comprehensive review.Conclusion: MDCT together with post-processing techniques permits accurate and early diagnosis allowing for the optimal management of chest trauma patients. Most chest injuries are readily detected, but others are more subtle requiring careful evaluation and interpretation.

C-276 Congenital and developmental thoracic diseases occasionally seen in adults: Imaging features J. Kim, E.-Y. Kang, O. Woo, H. Yong, K. Lee, Y.-W. Oh; Seoul/KR

Learning Objectives: To review and illustrate the characteristic imaging findings of congenital and developmental thoracic diseases occasionally encountered in the adult.Background: Developmental and congenital thoracic diseases are occasionally seen in adulthood. Some of these diseases can be mistaken for more serious lung diseases. Developmental and congenital lung disease in adulthood can be clas-sified into developmental anomalies predominantly affecting the airways and lung parenchyma and developmental anomalies predominantly affecting the pulmonary vessels. Case materials were selected randomly from two university hospitals. Patients were all over 18 years old. The majority of lesions were asymptomatic and incidentally found on chest radiographs and CT scans. Imaging features of congenital and developmental thoracic diseases were reviewed retrospectively.Imaging Findings: Adult cases of developmental anomalies affecting the airways and lung parenchyma included bronchial atresia (n=2), intralobar and extralobar

bronchopulmonary sequestration (n=6), congenital cystic adenomatoid malforma-tion (n=2), pulmonary and mediastinal bronchogenic cyst (n=6), tracheal bronchus (n=5), accessory cardiac bronchus (n=3), and tracheoesophageal fistula (n=1). Developmental anomalies predominantly affecting the pulmonary vessels included hypogenetic lung syndrome (n=1), unilateral proximal interruption of pulmonary artery (n=1), pulmonary arteriovenous malformation (n=6), and systemic arterial supply of the left lower lobe (n=3).Conclusion: This exhibit illustrates the characteristic imaging features of pulmonary congenital and developmental anomalies encountered in the adult. Radiologists must be aware of imaging features of congenital and developmental thoracic le-sions, which narrow down the differential diagnosis.

C-277 Multislice CT evaluation of the sternum T. De la Espriella, A. Roque, D. Porres Varona, J. Andreu, O. Persiva, E. Pallisa; Barcelona/ES (tdelae@hotmail.com)

Learning Objectives: 1. To describe and radiologically illustrate the normal anatomy of the sternum and most common variants. 2. To review the pathologic conditions affecting the sternum depicted by multislice CT (MSCT). 3. To familiarize the radiolo-gist with the assessment of the sternum in standard chest MSCT studies.Background: Lesions of the sternum can be clinically missed and misinterpreted as other pathologies. MSCT and its 3D reconstruction capabilities can detect such lesions, providing an aid to patient management and surgical planning, particularly in the case of sternal deformities. We emphasize the importance of reviewing the sternun when performing standard chest MSCT studies.Imaging Findings: First, we present anatomical diagrams and radiologic anatomy of the sternum, as well as its common anatomical variants. We review postopera-tive, infectious, tumoral and traumatic conditions affecting the sternum, as well as sternal deformities.Conclusion: Lesions of the sternum can be missed when performing a standard chest MSCT study. We illustrate the normal anatomy of the sternum and review its common pathologic conditions depicted by MSCT.

C-278 Localized fibrous tumors of the pleura: Correlation of radiologic and pathologic findings A. Piazza, M.A. Pastrana, P. Fraga, M. Reyero, C. Garcia Roch, J. de Miguel; Madrid/ES

Learning Objectives: To describe the most relevant clues for making a confident preoperative diagnosis of localized fibrous tumors of the pleura (LFTP), by com-paring their imaging findings (in CT and MR studies) with those features obtained through pathologic examination.Background: Localized fibrous tumors are rare primary pleural neoplasms that typically affect adults who may present with local or systemic symptoms or who may be asymptomatic. It is important to remember that these neoplasms may not exhibit the classic imaging features of extraparenchymal lesions. We show several cases of LFTP (including benign and malignant subtypes) in order to help familiar-ize radiologists with some of the radiologic features of these tumors. We also try to offer clues for differentiating benign from malignant processes.Procedure Details: We performed a longitudinal, retrospective, observational, non-randomized and analytical study that included cases of LFTP referred to our institution, and confirmed through pathologic evaluation. We included patients who underwent 16-detector-row CT (Siemens Sensation 16®, Erlangen, Germany) and/ or 1.5 Tesla MR (Siemens Magnetom Avanto®, Erlangen, Germany) studies. Imaging findings were compared with those features obtained from the pathologic examination in order to establish radiologic features for the characterization of these tumors.Conclusion: LFTP are relatively uncommon neoplasms, the diagnosis of which is frequently difficult to achieve from their imaging appearance. We offer some clues to identify these tumors and to predict their biologic behaviour, based on a radiologic-pathologic correlation of cases in our institution.

C-279 Management benefits and safety of computed tomography in patients undergoing extracorporeal membrane oxygenation therapy: Experience of a single centre S.L. Jepson, C. Harvey, J. Entwisle, G.J. Peek; Leicester/UK (stevejepson2@gmail.com)

Learning Objectives: To evaluate the benefits and logistical safety of computed tomography (CT) imaging in patients undergoing extra corporeal membrane oxy-genation (ECMO) therapy in a single institution.

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Background: At Heart Link ECMO Centre, Leicester, UK the vast majority of radiologi-cal imaging consists of portable plain X-ray and ultrasound. Occasionally, CT imaging is required to provide further information. Over a period of 25 months, 126 patients underwent ECMO therapy at this institution. The imaging of these patients was reviewed to identify patients who had CT imaging whilst on ECMO. Patient notes were retrospec-tively reviewed. CT findings and subsequent decisions were analysed to assess the benefit of CT imaging. Complications arising due to the logistics of performing the scan were analysed to assess the safety of performing CT in ECMO patients.Procedure Details: Of the 126 patients, 14 (11%) had a total of 15 CT scans whilst undergoing ECMO therapy. Indications for CT included new neurology, increased respi-ratory demand and increasing requirement for high ECMO flows. There were no major complications and two minor complications associated with the logistics of performing a CT scan on an ECMO patient. CT produced significant findings in 73.3% (11/15) of scans and in all 15 scans CT provided information that was utilised in making further management decisions, including, in some cases, withdrawal of ECMO therapy.Conclusion: With an experienced team, CT imaging of patients on ECMO can be performed safely. CT provides valuable information for subsequent management of patients undergoing ECMO therapy.

C-280 Tumours and masses of the pleura and chest wall: What the radiologist should know E. Kelliher1, A. Alzahrani1, T. Ramadan1, J. Ni Mhuircheartaigh1, E. Marom2, J. Bruzzi1; 1Galway/IE, 2Houston, TX/US (emma_kelliher@yahoo.com)

Learning Objectives:To review the clinically and diagnostically significant imag-ing findings of pleural and chest wall masses and tumours that are important for formulating a management strategy.Background: Although there is a wide range of different pathologies that may present as masses of the chest wall and pleura, most have similar imaging char-acteristics and are often difficult to differentiate based on their appearance alone. Examples include chest wall metastases, lymphadenopathy, neurogenic tumours, solitary fibrous tumours of the pleura and osteogenic tumours. However, knowledge of the pathophysiology of many of these abnormalities and detailed examination of their imaging appearance can help in interpretation and lead to a radiology report that is more diagnostically accurate and clinically useful.Imaging Findings: By means of images of gross surgical specimens and high-quality CT, MRI and PET/CT studies, we illustrate the important imaging features of different pleural and chest wall pathologies that will help to narrow the differential diagnosis and influence their subsequent work-up and management.Conclusion: Tumours and masses of the chest wall and pleura often have charac-teristic imaging findings, whose recognition is important for forumulating a correct differential diagnosis and guiding subsequent management.

C-281 Intercostal space imaging A. Villanueva, D. Aquerreta, A. Alonso-Burgos, J.J. Noguera, B. Zudaire, M. Arraiza, C.B. Hernandez; Pamplona/ES (avillanueva@unav.es)

Learning Objectives: 1. Recognize the normal appearance of the intercostal space (ICS) on various imaging techniques (Chest radiograhs, MDCT, ultrasound and MRI). 2. Illustrate the radiological findings of ICS disease.Background: Disorders of the intercostal space include not only tumours but also pseudotumoral lesions, inflammatory diseases and iatrogenic lesions. Many of these processes have a specific radiological findings that allows a definitive diag-nosis. Imaging techniques allow detecting, localizing, characterizing and guiding the therapeutic procedures in these entities. MDCT images have enabled precise localization of ISD and, sometimes, definitive diagnsis.Imaging Findings: Imaging findings of normal ICS anatomy and normal ICS structures that may simulate disease (intercostal veins crossing pleura that simulate malignant implants) are shown. Cases with diseases that affect the intercostal space are shown. Examples are classified as: 1) Infections (non-tubercoulous empiema necessitatis, hydatidic cyst). 2) Tumours such as non-neoplasm (extramedullary hematopoiesis, aggressive hemangyomas) and neoplasm that include primary benign tumours (lypoma, neurofibroma and other neurogenic turmours) and pri-mary or secondary malignant tumours (plasmocytoma, lymphoma, melanoma, ribs neoplasm). 3) Miscellany (iatrogenic and traumatic lesions such as intercostal muscle calcification, tumoral implants before interventional radiology procedures, enlargement of intercostal veins before acigos vein thromboses, lung hernia).Conclusion: The radiologist should always assess the ICS in chest radiographs and CT studies. Often, this space is not examined properly. Many diseases can affect the ICS and knowledge of them is essential in the diagnosis of ICS pathology.

C-282 Lung ultrasound in the follow-up of patients with decompensated heart failure M. Busso, L. Cardinale, A. De Pascale, G. Garofalo, A. Ramanzin, G. Volpicelli, C. Fava; Orbassano/IT (luciano.cardinale@gmail.com)

Purpose: The objectives of this study are to evaluate the potential of bedside lung ultrasound in assessing the evolution of pulmonary congestion in patients with acute decompensated heart failure (ADHF), as a result of medical treatment, and to compare ultrasonography with traditional chest radiography and brain natriuretic peptide serum level.Methods and Materials: We examined patients admitted to our emergency depart-ment (ED) with a diagnosis of acute decompensated heart failure. Each patient was studied at admission and after 4.5 + 3.1 (SD) days of medical treatment. US examination was performed bedside in a supine position, the ultrasonic feature of multiple and diffuse comet-tail artifacts B lines were investigated. Each patient underwent two chest radiographs, and a previously validated radiologic lung water score was used to assess pulmonary congestion.Results: 53 patients have been enrolled. 82% of chest radiographs had evidence of pulmonary edema. The radiologic score of EVLW was significantly reduced after medical treatment. All the lung US examinations showed multiple and diffuse an-terolateral B lines at admission. After treatment, the US artifacts were significantly reduced all over the lung surface in all 53 patients.Conclusion: Bedside lung, US provide reliable information on interstitial pulmonary congestion in the follow-up of patients with ADHF. Its accuracy is similar to other methods, such as serial chest radiographs. Ultrasonography represents an attrac-tive, easy-to-use bedside diagnostic tool for monitoring pulmonary congestion in decompensated heart failure.

C-283 Echo contrast ultrasound in subpleural consolidations F.A. Bertolini1, C. Görg2, G. Mathis1; 1Rankweil/AT, 2Marburg/DE (franzbertolini@gmx.at)

Purpose: To evaluate the enhancement of Sonovue in different subpleural con-solidations.Methods and Materials: In this study, 2.4 ml of the contrast agent BR-1 (Sonovue) is injected in a cubital vein to measure the saturation and the time of enhancement in the lung parenchyma. CEUS of 20 patients with obstructive atelectasis (n=5), pneumonia (n=5), pulmonary embolism (=PE) (n=5) and lung carcinoma (n=5) were investigated with a grey value analyzer (ImageJ) to evaluate the brightness in the lung parenchyma. A time interval of 0.2 seconds allows a precise measurement of the signal enhancement.Results: Atelectasis filled up to 44.91% 5.5%, pneumonia up to 44% 0.6% of the brightness spectrum. Pulmonary embolism (=PE) filled up to 6.34% 0.6%, and therefore practically no saturation. Lung carcinomas showed a maximum up to 37.25% 3.75%. Atelectasis began to saturate at 5.6s 087s the maximum was at 10.16s 2.01s. Pneumonia filled at 4.96s 0.87s, max Saturation began at 8.92s 1.47s. PE showed no signal enhancement. Lung carcinomas started at 14.64s 5.36s and ended at 21.16s 5s.Differences 10s after the injection: Atelectasis vs. Pneumonia showed no significance; atelectasis vs. PE p=0.0007; atelectasis vs. Carcinoma p=0.01; pneumonia vs. PE p=0.000002; pneumonia vs. Carcinoma p=0.0005; PE vs. Carcinoma p=0.03.Conclusion: Significant differences of various subpleural consolidations in the CEUS can be shown with a grey value analyzer by contrast enhanced US.

C-284 Endoscopic and CT findings of tracheal cysts A. Bray; Rome/IT (leonarducciolo@yahoo.it)

Purpose: Objective of this is to define the morphology, the localization and fis-tulous channel of tracheal cysts through multislice CT and 3D with endoscopical correlation. To evaluate preoperative anatomical relationships and the differential diagnosis by CT and endoscopic findings.Methods and Materials: 8 pz with tracheal cysts were studied by multislice CT with multiplanary and 3D reconstructions for the identification of the paratracheal anatomical relationships, the localization, the morphology and the fistulous chan-nel detection. In 3 pz it has been carried out virtual endoscopy CT 3D. In 2 pz it has been performed MR examination. All pts have been studied by tracheal endoscopic examination.Results: CT associate to bronchial endoscopy concur in greater diagnostic speci-ficity and better therapeutic planning for a resolutive surgical treatment. Also in the cases of recidive paratracheal cysts after surgical treatment by means of VATS (Video Thoracic Surgery), CT has demonstrated an elective role in preoperative

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endoscopic planning EBUS-FNA (endobronchial ultraSonography [water filled ballon] - fine needle aspiration) and in the follow-up.Conclusion: Multislice CT to thin layer with multiplanar elaborations and 3D reconstructions is the examination of election for the diagnosis, the nosological organization and the endoscopical preoperative planning of the tracheal cysts.

Computer Applications

C-285 Medico-legal issues in teleradiology A. Pinto, M. Scaglione, G. Ponticiello, G. Ruggiero, G. Russo, L. Di Nuzzo, L. Romano; Naples/IT (antopin1968@libero.it)

Learning Objectives: To discuss the current status of medico-legal issue in telera-diology pertaining to medical qualification, medical liability insurance, data security, radiologist duties, interprofessional and professional relationships with patients. To make suggestions for minimum ethical standards for teleradiological practice.Background: Teleradiology is the electronic transmission of radiographic images from one geographic location to another for the purposes of diagnosis and/or consultation. With the advent of high-speed, high-resolution digital imaging and network transmission, teleradiology promises to change the mechanism for inter-preting radiologic images and the traditional relationships among radiologists and patients and referring physicians. The medico-legal concepts surrounding such an innovation remain in large part unclear.Procedure Details: A recent Medline search on “medico-legal issues and tele-radiology” and “ethics and teleradiology” found only thirteen articles. The legal implications of teleradiology are addressed (including medical qualification, medical liability insurance, data security, radiologist duties, interprofessional and profes-sional relationships with patients). Pertinent literature and professional guidelines from the UK and USA are reviewed.Conclusion: The moral obligation to use teleradiology depends on both its ef-fectiveness and efficiency. Today, teleradiology gives rise to many unanswered medico-legal questions.

C-287 How to read radiological literature: An evidence-based medicine approach dedicated for radiologists A.N. Chalazonitis1, J. Tzovara1, G. Tsimitselis2, P. Porfyridis1, A. Fatsi1, M. Avlianos1, K. Papaioannou1, N. Ptohis1; 1Athens/GR, 2Larissa/GR (red-rad@ath.forthnet.gr)

Learning Objectives: 1. To show how to access and acquire evidence-based radiological literature. 2. To demonstrate how to compose questions in radiology, how to access the best information and finally how to appraise these information for validity and relevance. 3. To differentiate browsing (reading for the fun of it) from focused searching and/or systematic review.Background: When searching medical literature, the vast volume of information being published and the lack of training in how to separate the strong from the weak studies are substantial and important problems for radiologists. Publication does not always guarantee “quality”. Therefore, medical literature must be classified according to its quality level ranging from the highest to the lowest quality.Procedure Details: The purpose of this exhibit is to help radiologists who have no postgraduate special training in research to use evidence-based medicine and, where appropriate, “technology assessment” principles to construct a more definite knowledge basis for every day radiological practice, thus providing the best medical imaging choices for patient care. Ways of assessing the quality of published medical papers will be evaluated. A complimentary list of reference databases, indexes and targeted engines as well other tools for the most thorough literature search will be also provided to all participants.Conclusion: In radiology, practical resources to support evidence-based decisions are rapidly evolving. Acquisition and development of a new strategy in literature searching and critical appraisal is the key that improves the quality of both patient management and research in radiology.

C-288 Radiology search (www.RadiologySearch.net): A peer-reviewed and customizable radiology search engine R. Talanow; Cleveland, OH/US (roland@talanow.info)

Learning Objectives: To create a radiology-specific and peer-reviewed radiol-ogy search engine, with high validity and reliability, customized to the individual user’s needs.Background: Many Internet search engines display non-specific search results. It is time-consuming to filter desired information. Radiologists need a tool to search and display radiology-specific and peer-reviewed contents. Non-radiology contents need to be filtered to find more targeted hits, thus reducing time needed to find the sought information.Procedure Details: This is a free service, which is exclusively dedicated to search-ing and displaying radiological contents. Peer-reviewed contents and websites are included in the search engine, thus shortening the time needed to find relevant

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information and increasing the specificity of the results. This includes, but is not limited to, general and specific searches for cases, images, publications, radiologi-cal societies and news. Users may tailor their searches to their specific needs in a dedicated preference section.Conclusion: This user-tailored radiology search engine increases the specificity and reduces the amount of time the radiologist needs to find the desired information. Validity and reliability are high due to only searching peer-reviewed contents. Cus-tomization of the search engine satisfies the individual’s preferences and needs.

C-289 RaPSTToR: An interactive, multidisciplinary, web-based content management system for teaching radiology, surgery and medicine residents B.A. Ahmed, S. Albahrani, R. McLeod, N. Jaffer; Toronto, ON/CA (bilal.ahmed@utoronto.ca)

Learning Objectives: To describe and discuss an interactive, multidisciplinary, web-based content management system developed to enhance the learning of radiology.Background: Clinical residents often find it difficult to learn about radiology and pathology related to specific diagnoses of interest from existing Picture Archiving and Communication Systems (PACS). Most existing electronic tools designed for teaching purposes show few select images that focus on obvious abnormalities, and are thus not conducive to a full radiological and pathological review of the case by the learner. The goal of this project is to develop a web-based interactive teaching and evaluation tool to allow surgical and medical residents and students to learn from clinical cases using comprehensive images from radiology and pathology.Procedure Details: We created an interactive, web-based content management system that integrates structured case information with radiology and pathology images. Radiology Pathology and Surgical Teaching Tool for Residents (RaPST-ToR), was developed in the ASP.NET and C# programming languages using the Microsoft dotNET framework. A relational database was managed and stored using Microsoft SQL Server 2005. RaPSTToR allows for easy uploading and viewing of images, including complete CT scans. Users can test themselves by working through a case in a stepwise fashion. During this process, users have the chance to type their interpretation of the presented imaging and slides into the system and later compare it to the official report by the radiologist or pathologist.Conclusion: RaPSTToR is a comprehensive teaching and self-evaluation tool for residents, incorporating case information with radiology and pathology images.

C-290 Semi-automated volumetry of the cerebrum, temporal lobe, and cerebellum-brainstem on 3D brain MR images N. Hayashi, S. Sanada, M. Suzuki, Y. Matsuura, T. Yamamoto, O. Matsui; Kanazawa/JP

Learning Objectives: To describe automated volumetry of the cerebrum, cerebel-lum-brainstem, and temporal lobe on 3D brain MR images. To describe automated assessment of regional volume relative to brain volume. To learn automated seg-mentation of each region on 3D brain MR images.Background: Volumetry of the cerebrum, cerebellum-brainstem, and temporal lobe on brain MR images is important for clinical diagnosis of brain atrophy, e.g., in Alzheimer’s Disease (AD) and schizophrenia. The regional volumetry of the brain is also important for clinical diagnosis. The volumes of brain regions are calculated manually from T1-weighted images. However, manual measurement is subjective and is vulnerable to errors between operators. Here, we report an automated method for volumetry of the cerebrum, cerebellum-brainstem, and temporal lobe on brain MR assessment of the ratios of each volume to total brain volume.Procedure Details: Automated volumetry consisted of the following three steps: 1) Segmentation of brain regions using region growing; 2) Separation of the cerebrum and cerebellum-brainstem from segmented brain images; and 3) Segmentation of the temporal lobe from segmented cerebrum images. Ratios of each volume to total brain volume were calculated from automatic segmented images. The results of automated volumetry were approximately consistent with manual volumetry. In addition, ratios of each region were also consistent with those obtained by manual calculation.Conclusion: Automated volumetry of the cerebrum, temporal lobe, and cerebel-lum-brainstem on 3D brain MR images may be useful for clinical diagnosis and to support computer-aided diagnosis of brain atrophy on MR images.

C-291 Understanding multimedia: Basic principles of interactive learning in radiology J. Weidemann, C. Schlorhaufer, G. Diekhaus, M. Galanski; Hannover/DE (j.weidemann@mac.com)

Learning Objectives: To understand the basic principles of interactivity in multime-dia learning environments. To describe what you can learn from your interdisciplinary clincical conferences and side-by-side training. To describe the concepts of self-paced, explorative and tutor-based learning in multimedia computer programs.Background: One of the primal tasks of a radiologist is to write a report with all the findings in a particular case. This report helps the clinician, in making a diagnosis or in planning a therapy, as well as the residents in (radiological) training. These reports are composed mostly of a structured text and some sample images or un-commented image series. This combination is often insufficent to communicate the gain of knowledge from the radiological examination. Because of this, the radiologist demonstrates the case and responds interactivly to questions from the clinician or resident during a conference or side-by-side in the reading room.Procedure Details: The educational exhibit starts with a discussion of these typical clinical learning environments. The concepts of self-paced, explorative and tutor-based learning as well as the possibilities of current software authoring tools to de-pict this communication process will be discussed. We will show pitfalls in multimedia design like cognitive overload due to bad interface design. All steps of the exhibit will be illustrated with examples from our multimedia teaching library. Interactive examples will also be available after the congress on a dedicated web site.Conclusion: The combination of self-paced, explorative and tutor-based learning of radiological knowledge supports different learning styles in electronic multimedia environments.

C-292 Process management in DICOM data exchange between hospitals N. Teodorovic, M. Uesbeck, A. Weilenmann, A. Rhyn, R. Naef; Zurich/CH (teodorovic@usz.ch)

Learning Objectives: To optimize DICOM data exchange between hospitals. To implement a hospital wide electronic ordering system for PACS data import and export. To track and analyze the data volume that is exchanged.Background: After successful PACS implementation, a hospital is capable of sending DICOM data of a radiological investigation in short time to as many desired external destinations via several paths. Furthermore, it is possible to receive DICOM data of external radiological investigations on different paths. The variety of possible destinations, transmission paths, ordering and receiving institutions, etc. demands a suitable management system for DICOM data exchange.Procedure Details: A system was implemented which offers the functionalities described above and represents an optimization of the workflow for all parties involved. Thanks to the sophisticated design of the underlying MSSQL data base, it is possible to manage unlimited receivers, orderers, executing persons, persons to be notified and DICOM data transmission paths. An ASP.NET web application is used to provide a hospital wide order form for data export and import. The ap-plication comprises a tracking tool for all placed orders, as well as a tool, which provides work lists for every involved person and tools for statistical analysis. In case of ordering DICOM data from external partners, the order will be sent via secure mail protocol. An implementation of the application at partner hospitals requires an intranet and an outwards secure mail connection.Conclusion: The implemented application provides a genuine process manage-ment tool for DICOM data exchange for involved hospitals.

C-293 Vascular post-processing, the shorter way to diagnosis: Modern concepts and new update C.N. De Cecco, M. Rengo, P. Paolantonio, R. Ferrari, F. Iafrate, A. Laghi; Rome/IT (carlodececco@gmail.com)

Learning Objectives: The aim of this work is to analyze the actual post-process-ing techniques, focusing in particular on their clinical applications, pitfalls and new update.Background: Vascular post-processing techniques represent nowadays an ir-replaceble instrument for the evaluation of vascular disease. Maximum intensity projection (MIP), multiplanar reformations (MPR), curved multiplanar reformations (CMPRs), volume rendering (VR), auto-bone extraction, colorimetric plaque analysis and automatic diameter measurement permit an accurate depiction of lumen, evalu-ation of diameters, and localization and characterization of plaques. The results are also foundamental in the evaluation of aberrant or occluded vessels, and are also precious in pre-surgical planning (virtual surgical procedures).

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Imaging Findings: We present images of all post-processing techniques, focus-ing in particular on tips and potential pitfalls. We also want to focus attention on the importance of setting a correct viewing window, in order to avoid interpretation problems.Conclusion:Cardiovascular radiologists should be confident with post-processing thecniques. They should know also the potential pitafalls and the clinical advantages. These softwares represent a powerful tool in vascular evaluation and permit reduction of the mean analysis time.

C-294 Guidelines for developing a successful quality assurance program for a radiology department C.-S. Yam, J. Kruskal; Boston, MA/US (csyam@bidmc.harvard.edu)

Learning Objectives: The purpose of this exhibit is to provide essential techni-cal guidelines for developing a successful quality assurance (QA) program for a radiology department. The guidelines are aimed at both clinical and technical QA aspects. Step-by-step examples for the design and implementation of four QA-related programs will be demonstrated. ECR conference attendees can use information from this exhibit to create their own QA programs.Background: The three essential guidelines are: simplicity, security and avail-ability.Procedure Details: Simplicity: The QA applications must be accessed easily by any-one in the department or hospital, anywhere and anytime. Based on our experience, web-based front-end is the most appropriate choice. Security: The QA applications must be executed in a secured manner to protect patient information (e.g., HIPAA compliance in the USA). Availability: The QA system (e.g., a web server) must be maintained and supported in a 7/24 operation mode. Based on our experience, most hospitals already have the capability to provide this service.Conclusion: For different radiology settings, QA programs can be created differently for various purposes. However, the essential guidelines for developing, operating and maintaining a successful QA program are based on three major rules: simplic-ity, security and availability. In this exhibit, we demonstrate the development of four successful clinical applications used in our QA program. Step-by-step discussions in how to select components during the design and implementation phases will also be provided.

C-295 E-learning and radiology: Myths and facts A.N. Chalazonitis, D. Koumarianos, J. Tzovara, N. Ptohis, F. Laspas, G. Neofitou, M. Kelogrigoris, I. Apostolakis; Athens/GR (red-rad@ath.forthnet.gr)

Learning Objectives: 1. To describe the wide spectrum of e-learning as a new edu-cational environment. 2. To explain how e-learning can be a useful educational tool for radiologists. 3. To present a true e-learning scenario designed for radiologists.Background: The popularity of e-learning has increased considerably in the last few years. Constantly increasing use of PCs, easy and wide Internet access, and rapid telecommunication technology progress are some of the main reasons of this popularity. Education of this type supports the process of learning with the incorpora-tion of animated pictures, diagrams, forms, sound and video, designed in multimedia modules. Interaction between the instructor and the participant is enhanced.Procedure Details: In our exhibit, we shall attempt to present a conceptual clarifica-tion of the term e-learning. Synchronous interaction and asynchronous support in web-based educational systems will be analyzed in details. Long distance educa-tion, adult education, continuing education and lifelong learning will be presented as they may be parts of the e-learning process. Learning modules in the era of developed and completed training units will be also presented. Advantages and disadvantages of these educational frameworks especially in the radiology environ-ment will be systematically evaluated. Finally, a true e-learning scenario designed for radiologists will be presented.Conclusion: Today e-learning constitutes a successful educational tool that forces trainees to act as active participating members in the process of learning. Not only straightforward technological approach but careful instructional design of all e-learning radiological programs is mandatory to deliver competitive advantages over traditional education methods.

C-296 Viewing 4D cardiac CTA datasets with quicktime VR: An alternative to real-time dynamic volume rendering C. Wang, P. Quick, A. Persson, Ö. Smedby; Linköping/SE (chunliang.wang@imv.liu.se)

Learning Objectives: To understand the principle of the QuickTime VR (QTVR) technique to visualize 4D datasets in diagnosis and education.Background: For evaluating cardiac motion, multiphase (4D) volumes can be ren-dered with dynamic Volume Rendering (VRT) in a continuous loop, which requires powerful workstations. An alternative is to render one projection at a time, save the images in a QTVR movie, and then view them interactively on any computer.Procedure Details: QTVR files contain images in different projections, arranged in a grid, so that users can rotate the object around two axes by “panning” horizon-tally or vertically. Each projection can also be an animation loop. After segmenting desired or cutting away unwanted structures, QTVR movies are created in Osirix, using VRT, MIP, or both, in a predefined projection order. In addition to rotating the object, a cut plane can be applied and rotated. For educational purposes, a sound track can be added. The created movie can be viewed on any computer using the free QuickTime player. A typical cardiac CTA movie (10 phases with 220 projections, rotating vertically and horizontally in 18° steps) is 40-80 Mbyte, and much easier to transfer than the original 2 Gbyte dataset.Conclusion: QTVR movies is a practical alternative for displaying 4D images on standard computers and might be valuable for demonstration and education purposes.

C-297 Radiology integrated training initiative: Are trainees using this new resource? S. Hussain, F. Almallah; Birmingham/UK (drsh9@hotmail.com)

Purpose: The Radiology Integrated Training Initiative (R-ITI) is a set of electronic learning modules developed by the Royal College of Radiologists in the UK. The purpose of this audit was to look at how this new resource was being used and implemented by the West Midlands Radiology Training Scheme - one of the largest training schemes in the UK.Methods and Materials: Data was collected retrospectively from radiology trainees in the first 3 years of training since this was the specific group which R-ITI modules are aimed at. Both objective and subjective data was collected with information gathered regarding initial impressions, ease of use of website and usage data.Results: Data was collected from 73% of the trainees in the selected group. 64% described their first impression as good/above average; however, 50% had not used the modules since being taught how to and only 5% had completed more than 20 modules. This was despite 78% stating they had no difficulty using the system. Textbooks remained the primary source of information for 64% when learning about a new topic, 54% when adding to existing knowledge and 73% when preparing for exams.Conclusion: Initial opinions are positive; however, initial take up and usage has been poor. Trainees however identified two ways in which integration of R-ITI could be implemented. Firstly, lecturers involved in the weekly teaching sessions should identify modules relevant to their lecture prior to the teaching session. Secondly, modules should be organised in a similar way to the postgraduate exams.

C-298 Application of a computer aided diagnosis (CAD) system in MR-mammography (MRM): Do we need whole lesion time curve distribution analysis? P.A.T. Baltzer, D.M. Renz, S. Beger, C. Freiberg, M. Gajda, O. Camara, W.A. Kaiser; Jena/DE (pascal.baltzer@med.uni-jena.de)

Purpose: CAD systems for MRM provide not only the possibility of semiautomatic most suspect curve detection, but also display the percentual distribution of time curves in an analyzed lesion volume. This investigation was performed to evaluate whether consideration of whole lesion information is diagnostically superior to most suspect curve characteristics.Methods and Materials: 329 patients undergoing operation of breast lesions after MR-Mammography (1.5 T, 0.1 mmol/kg bw Gd-DTPA) were analyzed prospectively using a CAD-system (Dynacad, Invivo, USA). Dynacad processes dynamic data and displays the results as a colour-coded overlay depending on the initial signal increase (50-100%; 100%) and time curve type (continuous increase; plateau; washout). The system automatically detects the most suspect curve and visualises the percentual curve type distribution in a defined volume of interest (VOI). Not threshold reaching lesions ( 50%) were counted negative. Binary logistic regression

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analysis (LRA) was performed on most suspect curve (1), curve type distribution (2) and combined (1+2) CAD data (3), followed by ROC analysis.Results: Pathology revealed 469 lesions (279 malignant, 190 benign). 240 malig-nant (86.0%) and 88 (46.3%) benign lesions were colour-coded by CAD. Diagnostic accuracy was found to be 81.4% (1), 80.7% (2) and 82.0% (3). Defining appropriate cut-off values, sensitivity and specificity of 80.3%/68.9% (1), 80.3%/75.3% (2) and 80.3%/72.6% (3) were found. LRA results differed significantly (p /=0.03) between 1/2 and 1/3, but not between 2/3 (p=0.31).Conclusion: Our results show a comparable diagnostic accuracy of CAD mea-sured dynamic data. When whole lesion dynamic data is considered, specificity tends to increase.

C-299 Comparison of diagnostic performance between multi-detector computed tomography and multi-planar volume rendering techniques in blunt chest trauma M. Le Guen, C. Beigelman-Aubry, P. Grenier, O. Langeron; Paris/FR (morgan.le-guen@psl.aphp.fr)

Purpose: Improving early diagnosis of unnoticed injuries following blunt chest trauma is a radiological challenge. The aim of this study was to compare a stan-dard multi-detector computed tomography (MDCT) to the same exam with post-processing tools and multi-planar volume rendering techniques (MPVR) in focus on the anterior segment of chest wall.Methods and Materials: 101 severely ill patients with a blunt chest trauma were included. Chest acquisition was performed that required a maximum effective slice thickness of 2.5 mm, with overlapping reconstructions of around half the slice thickness. First interpretation was compared with a second reviewer using post-processing tools. The rate of diagnosis of anterior chest wall trauma (sternum, chondro-sternal junction, retrosternal hematoma, internal mammary pedicles) was compared. 2-tests or Fisher’s exact test were used to compare proportions and rates when appropriate. Statistical significance was defined as a p value 0.05.Results: Post-processing tools with MDCT significantly improve diagnostic perfor-mance with 26 sternal fractures versus 11 diagnosed in standard exam (p 0.01). A sternal fracture was associated in 50% of case with chondro-sternal injury, which was exclusively detected with reformat (p 0.0001). Retrosternal hematoma was significantly diagnosed with MPVR (19 versus 9 with p 0.001) and has an excellent concordance with sternal fracture (kappa = 0.98). No internal mammary pedicle injury was noticed.Conclusion: The easiest tool used to detect anterior chest wall injury is the MPVR sagittal reformat with a bone window. Further studies are needed to assess the relation between myocardial damage and anterior chest wall trauma.

C-300 Automatic determination of absolute CT coordinates using a table inlay B.P. Selby1, G. Sakas1, S. Walter1, U. Stilla2; 1Darmstadt/DE, 2Munich/DE (pselby@medcom-online.de)

Purpose: CT series can be used to define a reference position for correction of tumor alignment in radio therapeutic cancer treatment by comparison of the pro-jected slices to digital radiographic images. Because the pose of the CT dataset with respect to the table is a priori unknown, a method is introduced that automatically evaluates the placement of a table inlay and generates absolute CT coordinates.Methods and Materials: CT slices of different sections of a patient on a CT table with an inlay were used to determine the actual table position and pitch angle with respect to a fixed coordinate system. The inlay was designed so that it was possible to unambiguously identify a respective table section by just one single CT slice. Automatic matching of the partly recorded inlay with a given model of the geometry gives the absolute position of the table origin and pitch. Results from manual 3D matching of the model to the inlay were taken as the gold standard.Results: Comparisons to the manual determination of the table alignment show that the absolute position of the table origin can be found with an accuracy of 0.5 times the voxel size. The deviation of the pitch value lies within 0.1°.Conclusion: Automatic model based matching of a table inlay provides a fast and accurate method to determine absolute CT table coordinates. The method can increase the reliability of alignment correction procedures and offers a practical solution to the problem of the absence of absolute CT coordinates.

C-301 Diagnostic performance of detecting pulmonary nodules with computer-aided detection systems on multidetector-row helical CT scans: Comparison of LungVCAR and Syngo LungCARE Y. Kawasumi, T. Yamada, K. Takase, T. Matsuhashi, S. Higano, T. Ishibashi, S. Takahashi; Sendai/JP

Purpose: Our purpose was to evaluate the performance of two commercial-based computer-aided detection (CAD) systems for pulmonary nodule detection on multidetector-row CT (MDCT) scans.Methods and Materials: Seventy MDCT examinations for the patients with multiple lung metastases were independently assessed by a radiologist and two kinds of CAD pulmonary nodule detection systems: LungVCAR (Advantage Workstation 4.3, GE Healthcare) and Syngo LungCARE (SIEMENS Medical Systems). 1.0 mm- (25 cases), 1.5 mm- (20 cases) and 2.0 mm-thick (25 cases) images were used. The radiologist initially counted the nodules, and then checked the images with CAD systems. Another radiologist and the initial interpreting radiologist reviewed all discrepancies between the radiologist and two techniques, and determined true pulmonary nodules by consensus. The performance of the two CAD systems was compared.Results: The radiologist detected 1058 nodules, LungVCAR detected 971 nodules, and LungCARE detected 841 nodules. 1150 nodules were regarded as true posi-tive. The detection rate of the radiologist, LungVCAR, and LungCARE was 92%, 51%, and 55%. False-positive rate of the radiologist, LungVCAR, and LungCARE was 0.04, 5.5 and 3.0 nodules per patient. The radiologist missed 95 true nodules, while all lesions were detected by CAD systems. Therefore, the detection rate of the radiologist would have improved to 95% with LungVCAR and to 98% with LungCARE.Conclusion: Detection rate of lung nodules by commercial-based CAD systems is inferior to that of radiologist and false positive rate of CAD systems is still high, but they can add the lesions that radiologists missed and would improve the de-tectability of radiologists.

C-302 Analysis of non-radiology queries for radiological data acquired more than 1 year ago P.M.A. van Ooijen, A. Broekema, M. Oudkerk; Groningen/NL (p.m.a.van.ooyen@rad.umcg.nl)

Purpose: Introduction of PACS allows easy access to old image data from patients. The general assumption is that the average storage time on PACS should be ap-proximately 2 years to handle the majority of the requests. The purpose of this study was to investigate how many old studies were requested for referral after 7 years of fully digital operation by referring physicians from outside the radiology department.Methods and Materials: A web based image viewer is connected to the Elec-tronic Patient Record (EPR) system with, at the time of our study from September 1-December 31, 2006, a storage capacity of approximately 1 year of image data. Unavailable data can be requested digitally. Only on the first request of a certain study is logged. After transfer to the web server, a study will remain there and can be accessed multiple times without additional requests to the PACS.Results: In total 3268 requests were recorded, 1592 (48%) for studies 1-2 yo, 711 (22%) 2-3 yo, 418 (13%) 3-4 yo, 296 (9%) 4-5 yo, 188 (6%) 5-6 yo, and 63 (2%) 6-7 yo. Therefore, 52% of the requests were more than 2 yo. In 2% even the oldest data in the PACS of between 6 and 7 years old were still requested. Average “age” of all requests was 29 months.Conclusion: The number of requests clearly indicates the requirement of older data for clinical routine. Furthermore, results show that this not only holds true for the most recent data, but also for data of up to 7 years old.

C-303 Computed assisted follow-up of hepatic lesions in CT: A new software O. Lucidarme1, O. Ernst2; 1Paris/FR, 2Lille/FR (olivier.lucidarme@psl.aphp.fr)

Purpose: In oncology, follow-up of focal liver lesions is of primary interest to assess the response to therapy. Measuring the lesions and locating them on the repeated CT is often tedious and time consuming. Our aim was to evaluate a new software (LMS-Liver, MEDIAN Technologies) designed to assist radiologists in the evaluation and follow-up of focal liver lesions.Methods and Materials: LMS-Liver is designed to: 1) extract the contours of hypoattenuating lesions identified by the user, measure volume and longest axial diameter, 2) locate a lesion on the subsequent CT and 3) automatically pair the lesions in the first and subsequent CTs in order to calculate their growth. These

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three steps are made possible thanks to an automatic extraction of the liver mask from the CT images. Two radiologists reviewed the portal phase of 29 follow-up CTs made of 2 (n=10), 3 (n=5) and 7 (n=1) consecutive examinations. The radiologists pointed out target lesions in the first CT of each follow-up series.Results: For 24 follow-up studies (83%), the liver mask was correctly extracted and the radiologists identified 122 lesions on the first examinations. 67 (80%) of the 83 hypoattenuating lesions had contours correctly extracted. LMS-Liver found the correct corresponding lesion in 80 cases (66%) and when not, suggested the correct axial slice for the lesion in 20 additional cases (16%). Additionally, LMS-Liver correctly paired 120 lesions (98%).Conclusion: LMS-Liver is an effective tool to evaluate liver lesions during follow-up CT examinations.

C-304 Interactive virtual bronchoscopy application for transbronchial needle aspiration support W. Wojciechowski, M. Duplaga, M. Socha, A. Urbanik, K. Sladek; Krakow/PL (wadim@mp.pl)

Purpose: Transbronchial needle aspiration (TBNA) still remains a challenging procedure for invasive pulmonologists striving for accurate choice of sampling place.Methods and Materials: The use of interactive virtual bronchoscopy for the support of TBNA was evaluated in the group of 19 patients with initial diagnosis of lung can-cer. The authors applied their own designed BronchoViewer application based on visualization toolkit library in support of TBNA with interactive virtual bronchoscopy (VB) generated from CT DICOM data on a personal computer.Results: Among 19 patients enrolled in the study, TBNA was performed in 45 places. The effectiveness of the procedure was assessed by the presence of lymph node elements and/or cancer cells in the sample. In 30 from 45 TBNA places, the lymph node or tumour samples were received (66.7%). The concordance between TBNA and final evaluation results (thoracic surgery procedures) was about 90%.Conclusion: The use of software enabling interactive VB before and during BF is a cost-effective option for enhancement of TBNA efficiency.

C-305 Fast and precise rendering of virtual MR-cholangiopancreatoscopy by a combination of thin-slice data acquisition and interactive visualization T. Yamagishi, T. Kawai; Tokyo/JP (yamagishi@uke.uni-hamburg.de)

Purpose: Improved spatial resolution of novel MR scanners allows high-resolution (HR) data acquisition. In this presentation, we made use of HR-MRCP data of clinical cases and created virtual MR-cholangiopancreatoscopy by interactive 3D rendering software with low time consumption.Methods and Materials: Ninety-six patients (22-81 years) scheduled for MRCP were allocated to this study. The source slice data (0.8 mm, 96 slices) were ac-quired in coronal planes with a navigator gated respiratory-triggering (prospective acquisition correction) using a 1.5 T MR system. The data were imported to a PC and using the interactive VOXEL-MAN software created back-face rendering 3D images. Quick time VR movies were created which allow viewing the sequential endoscopic images of the pancreaticobiliary system. Three orthogonal radiological planes of the source MRCP were integrated into the movies, which are showing the conic extent of the endoscopic viewing field. Qualitative assessment was performed with five-point scoring by board-certified endoscopists immediately after examination.Results: The post-processed images delineated were precise and realistic enough to recognize inner surface of the pancreaticobiliary structure. Endoscopic display-ing could facilitate an accurate grasp of the divergence of small branch from the main pancreatic duct and/or biliary tract. The thin-slice data acquisition allows non-cleaved rendering. No complicated segmentation was necessary because of high selectivity for the biliary system of the hydrography data. All processing could be completed within 30 minutes. The radiological planes are useful as external images like X-ray fluoroscopy.Conclusion: A combination of HR-MRCP data and interactive visualization program can perform a practical creation of virtual MR-cholangiopancreatoscopy.

C-306 Evaluation of the optimal viewing size on soft-copy reading in digital chest radiography Y. Bessho1, M. Yamaguchi1, H. Fujita1, M. Azuma2; 1Habikino/JP, 2Kashiwara/JP (betsushiyoy@opho.jp)

Purpose: The purpose of the present study was to investigate the impact of viewing size on soft-copy diagnosis for detecting abnormalities in digital chest radiographs and to verify the usefulness of reduced digital chest radiography.Methods and Materials: ROC analysis of clinical images was performed using the standard digital image database by the Japanese Radiation Technology Society. A total of 30 images with and 20 images without nodule samples were extracted randomly from the database and used for ROC analysis. A total of 100 images were prepared for observation of reduced and non-reduced images. Observers’ viewing image was adjusted as non-reduced size (large: 30 cm×30 cm) and reduced size (small: 15 cm×15 cm).Results: The estimated mean ( SD) of Az values was 0.782 0.047 for large size images and 0.742 0.086 for small size images. However, no statistically signifi-cant difference was found between the two groups (P=0.429). The viewing time of small size images (1201.4) was significantly shorter than that (1719.7) of large size images. A statistically significant difference was also found in viewing times between reduced and non-reduced digital image with Wilcoxon signed-rank test (P 0.05).Conclusion: This study provided important information that there was a statistically significant difference in viewing times between reduced and non-reduced digital chest radiography images whereas no significant difference was founded in Az value for the accuracy of diagnosis between the two groups. However, the double check method for chest X-ray screening would be done efficiently by changing viewing size (from 15 cm×15 cm to 30 cm×30 cm) to improve the specificity of diagnosis.

C-307 Visualize coronary arteries in 3D without slabs: A fast and reliable 3D segmentation software for coronary CTA C. Wang, A. Persson, J. Engvall, M. Gjerde, Ö. Smedby; Linköping/SE (chunliang.wang@imv.liu.se)

Purpose: For viewing 3D coronary CTA datasets, maximum intensity projection (MIP) and volume rendering (VRT) are often complemented with MIP slabs. We present new software for visualizing the coronary tree without slabs.Methods and Materials: The software is based on the “virtual contrast injection” algorithm, which uses the connectedness of the vessel lumen to separate the contrast-filled structures from each other. Unlike most software, it does not aim at defining the exact boundary of the vessels, but to separate high intensity structures from each other while preserving surrounding soft tissue and identify the vessel midline. The subsequent visualization step can utilize MIP or VRT. The software was evaluated in 40 clinical coronary CTA datasets acquired with 64-slice CT with the isotropic voxels of 0.4 mm and results were compared with interactive MPR images from the original datasets.Results: The average processing time was 7.4 1.80 min and the interaction time 5.2 1.7 min. 100% of main branches (LAD, LCX and RCA) and 86.9% (219/252) of visible minor branches were intact (at least one pixel soft tissue surrounding the contrast-enhanced lumen). Visually correct centerlines were obtained automatically in 94.7% (321/339) of the intact branches.Conclusion: “Virtual contrast injection” is a promising tool for coronary CTA post-processing providing good overviews of the coronary artery tree.

C-308 Study of radiology report quality and accuracy using voice recognition software I.J. Barros D’Sa, C. Phillips, P. Lindley, T. Goodfellow, R. Wellings; Coventry/UK (ijbd@hotmail.com)

Purpose: ‘Dragon Naturally Speaking 8.1’ software was installed in May 2006 along-side a RIS/PACS system. The software transcribes the spoken word into the RIS. The study assessed the impact of implementation of the software in reporting.Methods and Materials: Retrospective review of two consultants’ reports over a 13 month period (Apr’06-Apr’07). Plain film/USS/CT/MRI reports were assessed before installation and also after 1, 3, 6, 9, and 11 months. Reports were scored 0-3. 3/3: fully comprehensible report, no errors. 2/3: minor spelling/grammatical errors, report comprehensible. 1/3: significant spelling/grammatical errors with confusing report. 0/3: incomprehensible report. Results recorded were: total report numbers, % reports achieving 3/3 and mean report score for each month.Results: 11209 reports were assessed. Radiologist 1, pre-Dragon, reports scor-

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ing 3/3 was 89-99%. Mean score range, 2.90-2.99. After the first month, reports scoring 3/3 dropped to 62.5% for CT. After 6 months, USS accuracy/mean score, recovered fully. CT/MRI took 9-11 months. Radiologist 2, USS and plain film only; pre-dragon reports 3/3, range from 99.3-99.6%. Mean score range, 2.9-3. After 6 months, accuracy/mean score improved to pre-Dragon standards. The efficiency of reporting, both in terms of numbers and turn around time following software introduction, will be presented.Conclusion: The use of digital transcription software is a valuable addition to radiology but a learning curve occurs before pre-introduction report accuracy is achieved. The use of the software is beneficial to the radiologist with improved efficiency and increased report productivity.

C-309 Development of a temporal registration system to integrate CT images and RF information from commercial RF system Y.H. Mah, B.J.J. Abdullah, K.H. Ng, L.K. Tan, J.H.D. Wong; Kuala Lumpur/MY (basrij@um.edu.my)

Purpose: When attempting to assess success of RFA, clinicians review information from RF system, pre-RFA CT images and CT images during RFA independently. It is therefore difficult to ascertain the accuracy of needle placement with the delivery of RF energy into the tumour as the data is captured in two different pieces of equipment. In this paper, we described the development of a graphic user interface (GUI) application to co-register the RF information from a commercial RF system and CT images.Methods and Materials: Pre-RFA CT scanning was done before the procedure to plan the treatment. Information of the RF system, which included the temperatures at the ablation zone, power output, efficiency and annotation were recorded. CT fluoroscopy was used for positioning of the RFA probe and assessing the complete-ness of ablation. Matlab was used to develop the GUI application to integrate the RF system parameters to the CT fluoroscopy as well as the corresponding pre-RFA CT images based on table location.Results: The GUI allows clinicians to pinpoint a specific timestamp based on the RFA operation, and the corresponding CT images are displayed. The user is able to adjust the window levelling and to scroll between the sequences of the displayed CT images.Conclusion: The integration of the CT images and RFA data allows the clinician to correlate the information between the RF information, pre-RFA CT images and CT images during RFA. This system assists the clinician to understand the relationship between the RF information and ablation result.

C-310 Soft-copy reading of brain CT: Comparative performance study between high-grade and low-grade LCD in the electronic medical charts K. Yoshimura1, K. Shimamoto1, S. Naganawa1, K. Ichikawa2; 1Nagoya City/JP, 2Kanazawa City/JP (yosimura@met.nagoya-u.ac.jp)

Purpose: The purpose of the study was to compare the image contrast of brain-CT image among three kinds of liquid crystal displays (LCDs) with different image quality levels in the electronic medical charts.Methods and Materials: Our electronic medical charts system uses three types of LCDs as follows: (1) high-grade 2k-LCD for primary image interpretation; (2) low-grade general 1k-LCD for HIS terminal; and (3) notebook PC with an XGA display panel for RIS terminal. The luminance performance of each display device was measured using a telescopic luminance meter, and just noticeable difference (JND) was calculated for all of 256-step gray-scale levels. In 50 cases of brain-CT images, JND of the gray matter and the white matter were obtained.Results: The JND difference between maximum and minimum values in 256-step gray-scale of 2k-LCD, general 1k-LCD, and notebook PC were 463, 500 and 436, respectively. The JND difference between the gray matter and the white matter for each display were 40, 74 and 73, respectively. The JND difference of general LCD were wider than those of high-grade 2k-LCD, suggesting that image contrast of brain CT on general LCD was superior to that on 2k-LCD. Although the JND difference of notebook PC in 256-step gray-scale were lower than those of 2k-LCD, notebook PC was superior to 2k-LCD in the gray-scale levels for brain CT.Conclusion: The low-grade general 1k-LCD contrast resolution of brain CT may become provisional substitution of high-grade LCD.

C-311 Accuracy of image registration for head and neck cancer patients E. Salli, E. Ahtola, H. Koivunoro, T. Seppälä, L. Kankaanranta, S. Savolainen; Helsinki/FI (eero.salli@hus.fi)

Purpose: Image registration of head and neck entity is complex due to non-ri-gidity. The registration errors between two consecutive CT scans are estimated. Quantification of the registration errors is a prerequisite, e.g., for estimation of the inaccuracy of the radiation treatment dose planning.Methods and Materials: Two separate CT scans for the treatment planning of boron neutron capture therapy (BNCT) were acquired from 17 head and neck cancer patients, one before each consecutive treatment session 3-5 weeks apart. An individual head fixation mask was used. The image slices above the bottom of skull were registered using a rigid body model (RBM) and maximization of mutual information (MMI). The resulting transformation was applied to whole image volume including head and neck. Thereafter, the registration errors at the levels of different cervical vertebrae were measured by locally registering a 60x60x20 mm region around each vertebrae (MMI, RBM) and measuring the movement of the region due to the second registration.Results: At the level of first, fourth and seventh cervical vertebra the registration errors were 1.2 1.2, 2.7 1.9, and 4.4 2.7 mm (mean 1SD). The corresponding median errors were 1.1, 2.1, 3.2 mm while the ranges were [0.1-5.8], [0.5-7.4] and [1.1-10.2] mm.Conclusion: The success of head and neck fixation and thus the accuracy of the image registration in the neck area varied between the patients. In most cases, the registration was performed with good accuracy. However, in some cases a deformable image registration technique taking into account different bending of the neck would be useful.

C-312 Decentralised upload of data from data on CD for storage into the PACS P.M.A. van Ooijen, A. Broekema, M. Oudkerk; Groningen/NL (p.m.a.van.ooyen@rad.umcg.nl)

Purpose: With the digitalization of radiology departments, patient data are increasingly distributed using recordable CDs. Besides advantages in terms of cost and shipping, major disadvantages also exist (e.g. each vendor provides its own viewer on the CD and every hospital uses its own patient ID). The aim was to develop a convenient easy way of introducing these CDs into the normal workflow of the hospital.Methods and Materials: To allow easy upload of the DICOM data on the CDs into the PACS, a new software package, DICOMUploader, was developed.Results: DICOMUploader reads all DICOM-files from a CD on any workstation. Subsequently, patient name and available series are displayed and relevant series can be selected for upload after providing the in-house patient ID. The CD is not physically transported to the radiology department which allows the physicians to have access to the CD when necessary in case of an emergency. At the radiol-ogy department, the data are automatically retrieved using DICOMUploader and stored on the local harddrive. Then, patient reconciliation is performed using a DMWL connection and the data are sent to the PACS. The status of the CD is recorded in DICOMUploader. Using the same DICOMUploader software pack-age, the physician who uploaded the CD can also track whether his/her CD has already been handled.Conclusion: DICOMUploader provides an easy way to integrate external data into the normal workflow of the hospital. Furthermore, it allows the physician to retain his/her CD at his/her own department and to check track the upload status.

C-313 Virtual pleuroscopy of the diaphragmatic pleura: Myth or reality A. Khalil, H. Chabchoub, M.-F. Carette; Paris/FR (antoine_khalil@yahoo.fr)

Purpose: To evaluate the feasibility of the virtual pleuroscopy (VP) in the detection of the pleural plaques.Methods and Materials: 20 consecutive patients, having asbestos exposure, were explored by unenhanced multidetector CT-scan. The image display used a surface-rendering algorithm and produced perspective red-scale images with a matrix of 512 x 512. Each VP image simulated a coned-down view, with a variable cone angle to explore the diaphragmatic pleura. The camera was placed 1 to 2 cms above the diaphragmatic dome. Four views are studied by diaphragm: cranio-cau-dal, lateral tangential, anterior and posterior. The observed virtual pleura aspect was classified in 5 groups (gr): gr1=Rib band, gr2= lobulated pleural thickening, gr3=spicular, gr4=plaques and gr5=nodules. The results are compared to the other MDCT images using multiplanar reformatting.

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Results: The visualization of each diaphragm was optimal (35/40; 87.5%), limited (3/40; round atelectasis and asbestosis) or impossible (2/40; asbestosis). The clas-sifications of the studied 38 diaphragmatic pleura were: gr1 (n=15), gr2 (n=5), gr3 (n=11), gr4 (n=7), gr5 (n=0). The MDCT analysis showed normal pleura for both gr1 and gr2, a confirmed or beginning of fibrosis for gr3 and confirmed the presence of pleural plaques on the diaphragmatic pleura in all cases of gr4.Conclusion: The virtual pleuroscopy is a reality and not a myth. It is a feasible technique. Other studies are necessary to confirm these preliminary results.

C-314 Functional CT for quantifying tumor perfusion during tumor growth and antiangiogenic therapy in a rat model Z. Kan, J. Huang, S. Phonkitkarun, S. Kobayashi, J. Yao, C. Charnsangavej; Houston, TX/US (zkan@di.mdacc.tmc.edu)

Purpose: To evaluate functional CT (fCT) for quantifying tumor perfusion during antiangiogenic therapies and its relationship with histologic examinations.Methods and Materials: FN13762 tumors implanted in mammary gland or liver of Fischer rats were treated with SU5416, a single VEGF receptor inhibitor target-ing endothelial cell proliferation, and SU11657, a multiple VEGF, PDGF receptors inhibitor which also targets mature vessels. Follow-up fCT were performed to measure changes in tumor perfusion of blood volume (BV) and blood flow, etc. Tumor tissue slides corresponding to CT sections were examined to count immature microvessel density (MVD), a histological surrogate for tumor angiogenesis, and mature tumor vessels.Results: SU5416 and SU11657 treatments inhibited tumor growth (1,580 830 vs 2,330 980 mm3, P=.084, and 837 414 vs 5,080 1470 mm3, P=.017, respectively). SU5416 increased tumor perfusion (BV: 1.5 0.2 vs 1.0 0.2 ml/100 g), whereas SU11657 decreased tumor perfusion (BV: 2.3 0.7 vs 3.3 0.9, P .05). Immuno-histochemical assays demonstrated that SU5416 and SU11657 both significantly inhibited immature MVD; however, SU5416 increased the mature tumor vessels but SU11657 decreased mature tumor vessels. Changes in tumor perfusion cor-responded well to changes in mature vascularity but did not correlate with immature MVD. Perfusion in untreated tumors decreased during growth (BV 1-4 weeks: 5.4 1.3, 5.25 1.5, 3.15 0.9, 3.4 2.3 ml/100 g, Ps .05).Conclusion: fCT quantifies function of the mature vessels but not MVD. Therefore, fCT may be used to evaluate the antiangiogenic therapies that target mature tumor vasculature. The fact that tumor perfusion decreased during growth has to be taken into consideration when evaluating treatment effects.

C-315 Radiology request card audit D. Mondal, T.S. Conner, D.Y.F. Chung, N. Graham; Milton Keynes/UK (dipanjali_mondal@hotmail.com)

Purpose: Radiology departments face the challenge of an increasing workload whilst maintaining standards of care. Request cards provide vital information to justify and prioritise imaging requests and facilitate efficient transport of patients. This audit looks at the deficiencies found in request card completion which directly affect the level of service provided.Methods and Materials: 144 request cards were collected randomly from inpatient, outpatient and GP requests for X-rays, ultrasound and computed tomography. Details from each section on the request cards were recorded on an access data-base and the results were analysed for each separate field. Audit was presented at departmental meetings to emphasise the importance of completing request cards appropriately. Posters and screensavers were displayed in clinical areas to remind and encourage accurate completion of cards. A re-audit was performed, following a month education period, to ascertain whether there was an improvement in filling out request cards. 70 request cards were collected randomly as above.Results: First round results showed that 12.5% of request cards were completed correctly. Of particular concern were relevant laboratory data completed in 20%, urgency completed in 62% and transportation completed in 63% of cards. Second round results showed some improvement with 17% of request cards completed correctly. There was a significant increase in laboratory data showing 100% im-provement.Conclusion: Increasing the awareness of the importance of request card comple-tion increases the percentage of adequately filled cards. This in turn helps prioritisa-tion of patients, thus increasing the efficiency of the radiology service.

Contrast Media

C-316 Nephrogenic systemic fibrosis: What every radiologist must know A. Manzella, P. Borba-Filho, F. Farias, C. Ribeiro, L. Santana, J. Kaercher, C. Zelaquett, J. Santos-Filho; Recife/BR (adonismanzella@yahoo.com.br)

Learning Objectives: 1. To describe the most important features related to NSF. 2. To familiarize radiologists with this emerging entity. 3. To provide a review of the literature. 4. To discuss the current recommendations regarding the use of gado-linium-based agents in patients with renal failure.Background: Nephrogenic systemic fibrosis (NSF), previously known as nephro-genic fibrosing dermopathy, is a new rare idiopathic condition that affects patients with renal failure. NSF has been described with increasing frequency in the medical literature. It is characterized by cutaneous sclerosis that can often result in contrac-tures, pain and functional disability as well as systemic complications. Approximately 400 cases of NSF have been reported worldwide. Recent reports have suggested a possible link with exposure to gadolinium-based agents. As many as 90% of known NSF patients had previously received a gadolinium agent.Procedure Details: A review of the available literature on the subject will be pre-sented emphasizing the most important features of this rare condition. This exhibit will address the epidemiology, pathogenesis, clinical manifestations and diagnosis of NSF. The authors will also discuss the differential diagnosis and comment on the current recommendations regarding the use of gadolinium-based agents in patients with renal impairment.Conclusion: NSF is a disfiguring and potentially debilitating disease without ef-fective treatment or prevention regimen. Therefore, it is important for radiologists to be aware of this emerging systemic disorder.

C-317 Gas patterns in disease: Air, an undervalued contrast agent I.P. Gunatunga1, S. Singh1, R. Gadahadh2, G. Davies1, E. Morris1; 1Cardiff/UK, 2Swansea/UK (ishangune@gmail.com)

Learning Objectives: Air is an undervalued and free contrast agent which has characteristic imaging findings. To recognise the imaging features of normal distribu-tions of air in different anatomical locations. To demonstrate abnormal gas patterns on different imaging modalities and correlate this with pathology. To appreciate its implications for patient management.Background: Air is a free contrast agent. In most instances it delineates normal anatomy. In other cases, when recognised it highlights important pathology alerting the radiologist or clinician for timely intervention. It is an undervalued contrast agent.Imaging Findings: We aim to: 1) Review normal distributions of air/gas in the body. 2) Highlight a variety of pathologies where gas acts as an important contrast agent. 3) Review the common and uncommon radiological appearances of pathology on plain film, CT and ultrasound. 4) Discuss the implications of these appearances for patient management.Conclusion: Air is an undervalued and free contrast agent which has characteristic imaging findings. These findings may have benign or have serious implications for patient management.

C-318 Gadobenate dimeglumine: A decade of clinical experience M.A. Kirchin1, G. Pirovano2, N. Shen2, U. Halemane2, C. Venetianer2, J.R. Parker2, C. Schultz2, A. Spinazzi2; 1Milan/IT, 2Princeton, NJ/US (miles.kirchin@bracco.com)

Learning Objectives: To review published and unpublished efficacy and safety data on the higher-relaxivity MR contrast agent, gadobenate dimeglumine (Gd-BOPTA), and to discuss the implications for imaging specific patient populations.Background: Gd-BOPTA is an extracellular gadolinium (Gd) contrast agent, which transiently binds to serum albumin in vivo, resulting in markedly higher r1 and r2 relaxivity values at all magnetic field strengths compared to conventional Gd contrast agents. Gd-BOPTA was first approved for contrast-enhanced MR imaging of the liver in Europe in 1997. Its approval status now includes central nervous system (CNS) applications in the US and Canada, and both CNS and liver in Europe, Asia, and Australasia. The use of Gd-BOPTA for MR angiography (MRA), as well as cardiac and breast MRI, is also under investigation. Numerous studies have compared the clinical safety and efficacy of Gd-BOPTA with those of other available Gd agents.Procedure Details: Efficacy data from published inter- and intra-individual com-parative clinical trials involving 4,500 subjects and a variety of clinical applications (i.e., liver, CNS, MRA, breast) and dosing regimens are tabulated and reviewed. In

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addition, 10 years of safety surveillance data are summarized.Conclusion: After a decade of clinical use, published data demonstrate that the higher signal provided by Gd-BOPTA is advantageous for all clinical applications, and that a standard 0.1 mmol/kg body weight dose can replace higher doses of other Gd agents for routine MR applications. Moreover, Gd-BOPTA has demonstrated an excellent safety record throughout this extensive monitoring period.

C-319 A quantitative comparison of gadobenate dimeglumine, gadopentetate dimeglumine, gadoterate meglumine and gadodiamide in contrast enhanced MRI of the brain B.M.M.M. Termote1, J.E. Vandevenne2, M.P.J. Van denBekerom3, G. Verswijvel2, Y. Palmers2; 1Leuven/BE, 2Genk/BE, 3Amsterdam/NL (Brunotermote@gmail.com)

Purpose: Contrast-enhanced MPRAGE MR sequences are frequently used to evaluate dural venous sinuses for thrombosis. The purpose was to prospectively evaluate four different gadolinium contrast media for enhancement in the dural venous sinuses.Methods and Materials: Institutional review board approval was granted. The study accorded with international standards for good clinical practice. Each patient (n = 224) underwent one contrast-enhanced MPRAGE sequence. Patients were randomized for type of contrast medium (gadobenate dimeglumine, gadopentetate dimeglumine, gadoterate meglumine or gadodiamide), dose (0.1 and 0.2 mmol/kg) and for MR unit (1.0-T or 1.5-T). Quantitative assessment was performed us-ing regions of interest analysis of signal intensity in transverse sinuses and the brainstem to calculate vessel signal-to-noise ratio [SNR] and vessel-brainstem contrast-to-noise ratio [CNR]. Data were tested with analysis of variance (ANOVA). The authors state no conflict of interest.Results: Gadobenate dimeglumine demonstrated significantly higher CNR (p 0.009) compared to the other contrast media. The CNR between other contrast media was not significantly different. CNR was significantly higher (p=0.001) for all contrast media when using double dose instead of single dose contrast medium injection. The difference in CNR between a 1.0-T and 1.5-T MR unit is statistically significant (p 0.001).Conclusion: In this study, highest CNR in the transverse sinuses was seen using gadobenate dimeglumine. For all contrast media, double dose significantly improved CNR compared to single dose contrast medium injection.

C-320 Extravasation complicating mechanical power injection of intravenous iodinated contrast for CT scan in 55,272 patients S. Lau, H. Huang, S. Chan, C. Chan, T. Chan, F. Ching, T. Fung, C. Kam, W. Kan, T. Kong, K. Kwok, W. Lam, P. Poon, C. So, D. Tsang, W. Young, S. Choy, M. Tang; Hong Kong/CN (laushun@gmail.com)

Purpose: To determine the frequency, risk factors and patients’ outcome of extrava-sation injuries complicating intravenously injected contrast medium for contrast CT scan using mechanical power injectors.Methods and Materials: All incident cases of extravasation injury complicating mechanical power injection of contrast for CT scan are prospectively recorded in 14 hospitals during a period of 11 months. The data are calculated and compared with internationally published data.Results: There are 200 incident cases of extravasation being collected in the study period. The overall frequency is calculated to about 0.36% (200/55272) which is comparable to those internationally published data (range from 0.04 to 0.9%). The mechanical injection rate, intravenous angiocatheter size as well as the injected volume are highly variable. Demented, confused and unconscious patients who are unable to communicate, language barrier, prior or ongoing systemic chemotherapy, intravenous drug abusers, diabetes, debilitation and elderly are the most commonly encountered risk factors in these patients. The most common symptoms and signs are subcutaneous swelling at injection site. All injuries are categorized as mild to moderate severity and resolved on conservative management. None of the patients requires surgical consultation or intervention.Conclusion: The overall frequency of extravasation injury complicating CT scan using mechanical power injector is very low. All incidents are those mild to moder-ate injuries that resolved on conservative management and none of them requires surgical consultation or intervention. Difficulty in communication, chemotherapy, intravenous drug abuser, diabetes, debilitation and elderly are the most commonly encountered risk factors.

C-321 Meta-analysis of randomized controlled trials comparing the nephrotoxicity of isoosmolar iodixanol with nonionic, low-osmolar contrast media M. Heinrich, L. Häberle, V. Müller, W. Bautz, M. Uder; Erlangen/DE (dr.marcheinrich@gmx.de)

Purpose: To compare the nephrotoxicity of iodixanol with nonionic low-osmolar contrast media in randomized controlled trials.Methods and Materials: Studies were retrieved by a systematic search of MED-LINE, EMBASE, BIOSIS, Current-Contents-Medizin (CCMed), Science-Citation-Index-Expanded (SCI), and The-Cochrane-Central-Register-of-Controlled-Trials (CENTRAL) (August 2007). Bibliographies of all retrieved articles and meeting abstracts were also searched, and experts in the field were contacted. Eligibility and quality of trials, characteristics of participants, changes in serum creatinine levels, and incidence of contrast-induced-nephropathy were independently abstracted by 2 investigators using a standardized protocol.Results: A total of 846 citations (104 potentially relevant) were identified. 26 studies including data from 3098 participants were included in our systematic review. 13 trials including 1842 patients reported the incidence of a decrease in renal function. Those studies were analyzed using a fixed-effects and a random-effects model and meta-regressions. The Q-statistic indicated no significant heterogeneity (Q=16.6, p=0.17). A funnel plot and Begg’s test (p=0.25) did not suggest the presence of publication bias. The overall pooled relative risk (RR) for developing CIN using a random-effects model (95% CI) was 0.88 (0.61-1.25). Comparing iohexol with iodixanol the RR was 0.45 (0.26-0.76). Comparing monomers other than iohexol with iodixanol the RR was 1.2 (0.87-1.67). Meta-regression demonstrated no significant relationship between the RR and diabetes mellitus (p=0.28), baseline-serum-creatinine (p=0.12), age (p=0.47), gender (p=0.34).Conclusion: Administration of iodixanol is not associated with a reduced risk for CIN compared with the class of nonionic low-osmolar contrast media. However, it is associated with a reduced risk for CIN compared with iohexol.

C-322 Assessment of the use of short injection duration of contrast material to reduce the total injection volume in 64-slice coronary CT angiography F. Tatsugami, T. Kanamoto, G. Nakai, I. Narabayashi; Takatsuki/JP (sa104@rg8.so-net.ne.jp)

Purpose: To investigate the potential of short injection duration of contrast material to reduce the total injection volume in coronary CT angiography.Methods and Materials: 45 patients were divided into three groups receiving 0.8 mL/kg of contrast material (350 mgI/mL) injected with fixed duration of 14 sec (A; n=15), 0.8 mL/kg of contrast material injected with fixed duration of 10 sec (B; n=15), 0.7 mL/kg of contrast material injected with fixed duration of 10 sec (C; n=15); all patients then received 20 mL of saline. Contrast densities were assessed for the ascending aorta and proximal and distal coronary arteries where vessel diameters were 2.0 mm.Results: The mean flow rate was 3.3 mL/sec in group A, 4.4 mL/sec in group B, and 3.9 mL/sec in group C. The average attenuation in the ascending aorta for group B (430 HU) was significantly higher than that for group A (355 HU) (p 0.05), while there was no significant difference between groups A and C (384 HU) (p=0.45). All cases of attenuation in the coronary arteries measured higher than 250 HU. The average attenuation in each coronary artery for group B was significantly higher than that for group A (p 0.05), and there were no significant differences between groups A and C.Conclusion: Short injection duration allows a reduction in the total volume of contrast material to 0.7 mL/kg, while a steady contrast enhancement is maintained in the ascending aorta and coronary arteries.

C-323 Iodinated contrast media increase DNA damage during CT M.A. Kuefner1, S. Grudzenski2, N. Rief2, M. Heckmann1, S.A. Schwab1, W.A. Bautz1, M. Lobrich2, M. Uder1; 1Erlangen/DE, 2Homburg a.d. Saar/DE (michael.kuefner@idr.imed.uni-erlangen.de)

Purpose: DNA double-strand breaks (DSBs) are among the most significant genetic lesions introduced by ionising radiation. The aim of this study was to investigate in-vitro and in-vivo the effect of iodinated contrast medium (CM) on the number of X-ray induced DSBs.Methods and Materials: For in-vivo assessment, blood samples were analysed from patients undergoing computed tomography (CT) of the thorax (18 with and 20 without intravenous CM). In-vitro blood and fibroblasts were irradiated before and after addition of CM (10-1500 mGy). To evaluate the individual repair capacity,

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in-vitro irradiation of samples of every patient was performed (5 and 10 mGy). For determination of DSBs, Gamma-H2 AX immunofluorescence microscopy was used in isolated blood lymphocytes/fibroblasts.Results: In-vitro the number of DSBs was elevated up to 50% if CM was added before, and no effect was seen if CM was added after irradiation. Administration of irradiated CM after exposure did not show an increase of DSBs. No difference was found between monomeric and dimeric CM. Number of DSBs was higher in patients receiving CM during CT (0.185 0.1 vs. 0.15 0.1 DSBs/cell, means standard er-rors). In-vivo DSBs were repaired during 24 hours. In younger individuals, higher DSB repair capacity was found in-vitro and in-vivo.Conclusion: Iodinated CM elevates the number of radiation induced DSBs in-vitro and in-vivo at low diagnostic doses. This effect can be explained by increased photoelectric absorption in the contrast medium and the subsequent exposure of nearby lymphocytes to photoelectrons, whereas a chemical effect of CM can be excluded.

C-324 Superparamagnetic iron oxide-enhanced liver MRI with SHU-555 A (Resovist®): New protocol infusion to improve arterial phase evaluation. A prospective study L. Grazioli1, M. Bondioni1, L. Santoro2, G. Faralli2, L. Romanini1, S. Colagrande2; 1Brescia/IT, 2Florence/IT

Purpose: To compare the arterial enhancement in hypervascular hepatic lesions (HHLs) with slow and fast infusion after SHU-555 A (Resovist®) by T1-weighted 3D-GRE fat-sat sequence.Methods and Materials: In 2006/2007, we have prospectively evaluated 59 pts (80 known HHLs) with dynamic Resovist®-enhanced MR examination: 43 FNHs, 10 Adenomas, 7 Hepatocellular Carcinomas, 1 Cholangiocellular Carcinomas, 8 Hypervascular Metastases, 10 Nodular-Regenerative-Hyperplasias, and 1 extra-medullar-intra-hepatic eritropoiesis. Resovist was administrated with a bolus of 0.5 and 2 ml/s, for slow and fast infusion protocol respectively followed by 20 ml of saline-solution-flush using an automated injector and care-bolus technique. Three blinded readers evaluated by visual assessment the arterial enhancement using a score from 0 to 3: 0-none, 1-weak, 2-discrete, and 3-intense enhancement. In-ter-observer reliability was measured by Cohen’s Kappa-statistic and mean score differences by the non-parametric-Wilcoxon test.Results: Out of the 80 HHLs, 41 were examined using the slow protocol, 19 the fast, and 20 both. Relevant enhancement (scores 3+2) for slow and fast infusion protocols was found in 36-45.9% vs 7.6-15.3%. Intra-individual comparison evalu-ation confirmed the better results obtained by slow vs fast infusion protocols, and distribution of the scores of two protocols was statistically different (p= 0.0004). The slow protocol showed values between 0 and 3 with an arithmetic mean of 1.08, whereas the fast protocol showed values between 0 and 2 with an arithmetic mean of 0.66.Conclusion: Slow infusion (0.5 ml/sec) improves the arterial enhancement after SHU-555 A administration.

C-325 Myocardial delayed enhancement (DE): Time course of contrast-to-noise ratio (CNR) of infarcted myocardium (IM) to non-infarcted myocardium (NIM) and left ventricle cavity (LVC) after fractionated double dose (FDD) of gadobenate dimeglumine (Gd-BOPTA) F. Secchi, G.D.E. Papini, G. Di Leo, F. Sardanelli, G.P. Cornalba; Milan/IT (f.sardanelli@grupposandonato.it)

Purpose: To analyze the CNR time-course of IM-to-NIM and IM-to-LVC after FDD of Gd-BOPTA for myocardial DE.Methods and Materials: After IRB approval, we prospectively evaluated 13 postischemic patients (11 males; age, 63 11 years) who underwent MR at 1.5 T for DE-imaging (short-axis IR-FLASH) with the following protocol of Gd-BOPTA administration: 0.1 mmol/kg and DE-imaging after 2.5, 5, 7.5, and 10 min followed by 0.1 mmol/kg and DE-imaging at 12.5, 15, 17.5, and 20 min after the first admin-istration. Regions-of-interest on IM, NIM, LVC, and noise were used for measuring signal intensity (SI). Friedman ANOVA was used.Results: Noise ranged from 2.6 0.9 (mean standard deviation) to 3.0 0.7 (p=n.s). The median SI of IM showed double plateau time-course with a jump from 39.4 at 10 minutes to 50.0 at 12.5 minutes (p 0.001); SI time-course of LVC was paral-lel to that of IM with median values of 35.9 and 47.8, respectively (p 0.001); the median SI of NIM ranged from 4.2 to 6.8 (p=n.s). The median CNR of IM-to-NIM progressively increased from 24.7 at 2.5 minutes to 45.2 at 20 minutes (p=0.031) and that of IM-to-LVC showed a time-course ranging from 1.0 to 2.7 (p=n.s).Conclusion: The CNR of IM-to-NIM was high, reaching the top level at 20 minutes.

The CNR of IM-to-LVC was low and its changes were nonsignificant. The FDD of Gd-BOPTA resulted in a highly significant myocardial DE in contrast to the NIM but in a weak myocardial DE in contrast to the LVC.

C-326 Characterisation of cisplatin adsorbed iron oxide nanoparticles for biomedical applications M. Kettering1, H. Zorn1, S. Bremer-Streck1, H. Oehring1, M. Zeisberger1, C. Bergemann2, R. Hergt1, K.-J. Halbhuber1, W. Kaiser1, I. Hilger1; 1Jena/DE, 2Berlin/DE (ingrid.hilger@med.uni-jena.de)

Purpose: To characterize cisplatin adsorbed iron oxide magnetic nanoparticles (MNPs) in vitro in relation to a potential applicability in tumour treatments by com-bining magnetic heating with chemotherapy.Methods and Materials: Cisplatin was adsorbed to starch coated MNPs (target-MAG-MNPs) to give cis-targetMAG-MNPs. Magnetic properties and core diameter of nanoparticles were measured by VSM and TEM. The stability of cis-targetMAG-MNPs were evaluated in dH2O, buffer (PBS, 0.1 M, pH 7.4) or fetal calf serum (FCS, pH 7.4) at 4-120 °C up to 20 weeks. Stability measurements were done by determining hydrodynamic diameters with laser diffraction and iron and platinum contents with atomic absorption spectrometry. The nanoparticle heating potential was determined calorimetrically.Results: A maximum of 10.3 1.6 mg (dH2O), 10 1.6 mg (PBS) and 13.4 2.2 mg (FCS) cisplatin/g Fe could be adsorbed to MNPs. Magnetization data of MNPs showed superparamagnetic behaviour. No distinct differences in the core (around 12 nm) and hydrodynamic diameter (around 73 nm) were observed between na-tive and functionalized MNPs. If suspended in dH2O, cis-targetMAG-MNPs were stable at 4 °C and 22 °C for 2-4 weeks, whereas 40-80% of cisplatin was desorbed in PBS or FCS during that time period. The heating potential was 75.5 1.6 W/g (400 kHz, 24.6 kA/m).Conclusion: According to the observed magnetic and constant structural proper-ties, together with the possibility of a facilitated cisplatin release in physiological media, an applicability of nanoparticles for local tumour therapies seems to be possible in the long term.

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Female

C-327 Solid components in endometriotic cysts: The role of MR imaging in detection and diagnosis Y. Okajima, A. Tamura, Y. Matsuo, Y. Onoda, S. Fuwa, M. Matsusako, K. Suzuki, Y. Saida; Tokyo/JP (yk_okaji@yahoo.co.jp)

Learning Objectives: To learn imaging findings of endometriosis-related neo-plasms and their mimics with pathological correlation. To recognize the role of MRI in diagnosis.Background: Endometriotic cysts are precancerous lesions. Detection of cancerous lesions is a major role of MRI, and it is the first step to find out solid components. Contrast study is necessary to exclude clot. Endometrioid adenocarcinoma and clear cell adenocarcinoma are the most common. Besides malignant neoplasms, benign and borderline neoplasms also arise in endometriotic cysts. Considering the high prevalence of endometriotic cysts in young women, accurate preoperative diagnosis is desired to preserve fertility.Imaging Findings: T1WI is useful to detect solid components in endometriotic cysts. Dynamic contrast study is helpful in diagnosis. Depicting enhanced nodules in hyperintense cysts on T1WI is sometimes difficult, and dynamic subtraction images are useful. Endometrioid adenocarcinoma and clear cell adenocarcinoma typically show hypo- or isointensity on T2WI and extremely hyperintensity on DWI with strong enhancement. Clear cell adenocarcinoma often demonstrate smooth surface and sometimes contain cysts especially in large nodules. DWI is useful in depicting cancerous lesions. Endometriotic cysts with malignant transformation tend to increase in size and show hypointensity on T1WI and hyperintensity on T2WI due to secretion of tumors. Adenosarcoma contain hemorrhage and edema. Mullerian mucinous borderline tumors show extremely hyperintense papillary projections on T2WI, while benign adenofibroma show extremely hypointensity nodules. Decidual changes resemble placenta. We will also demonstrate pitfalls.Conclusion: Accurate detection of solid components in endometriotic cysts and detailed evaluation of their configuration and signal intensity are indispensable.

C-328 The many faces of pelvic endometriosis: Imaging findings with emphasis on unusual presentations S. Choudhary, N. Fasih, C. Walsh, D. Papadatos; Ottawa, ON/CA (docshaile@gmail.com)

Learning Objectives: 1. To highlight the unusual manifestations of endometriosis with emphasis on the differential diagnosis. 2. To describe the cross sectional im-aging appearances of the disease. 3. To describe the distinctive imaging features on pelvic MRI.Background: Endometriosis is a relatively common gynecological problem in young females. Prevalence figures quoted are 0.5-5% in fertile and 25-40% in infertile women or 10% of all women in reproductive age group. Imaging techniques have greatly facilitated the evaluation of this condition. However, the disease is in continuous evolution due to its atypical localizations and appearances. In typical locations, the diagnosis is simple with the three imaging hallmarks being endometrial implants, endometriomas and adhesions. However, this relatively common entity may present as a diagnostic challenge to the radiologist when unusual presenta-tions are encountered. These varied manifestations have opened a new frontier for the gynecologist as well as the radiologist.Imaging Findings: In this exhibit, we present imaging of few of the unusual manifestations of the disease we have encountered including invasive polypoidal endometriosis, endometriosis within the vagina, malignant transformation, nodular endometriosis in abdominal wall, endometriomas with recurrent haemorrhagic ascites, round ligament implant and bowel wall involvement.Conclusion: Endometriosis should be considered in the differential of all patients in reproductive age group with pelvic symptoms. Knowledge of the varied appear-ances provides new insight in the understanding of this disease and will help us to confidently diagnose this pathology.

C-329 The imaging appearances of metastatic breast cancer simulating primary gynaecologic malignancy A.G. Rockall, N. Bharwani, P. Narayanan, S. Vinnicombe, A. Sahdev, R.H. Reznek; London/UK

Learning Objectives: 1. To appreciate the range of appearance of metastatic breast cancer in the pelvis and abdomen, which may simulate primary ovarian, cervical or endometrial cancer. 2. To learn the imaging features and biopsy techniques that may help in distinguishing between primary gynaecologic malignancy and breast cancer metastases.Background: Intra-abdominal spread of disease from breast cancer is a well-recognized phenomenon. The appearance of metastatic breast disease in the abdomen may be indistinguishable from primary ovarian carcinoma, which may co-exist in patients with breast cancer. In addition, post tamoxifen, endometrial changes may be seen, simulating a carcinoma. Rarely, a metastatic deposit may be present on the cervix, mimicking a cervical carcinoma. Appropriate treatment relies on distinguishing a new primary from metastatic disease.Imaging Findings: We will illustrate the imaging appearances of patients with known primary breast cancer and metastatic disease to the abdomen and pelvis, including transcoelomic spread in the peritoneal cavity, ascites and deposits in the omentum, peritoneum, bowel, ovaries and sites typical for ovarian cancer. We will demonstrate cases in which post treatment endometrial changes or cervical involve-ment may mimic primary tumours in these sites. For comparison, we will also show examples of primary disease in these sites, stressing the need for biopsy confirma-tion. We will describe the biopsy techniques used to make this distinction.Conclusion: Knowledge of the pattern of disease dissemination in breast can-cer aids in the detection of metastatic disease. An appreciation of the potential overlap in appearances with primary gynaecologic disease may direct further investigations.

C-330 Multimodality approach to the proper diagnosis of gestational trophoblastic disease: Correlative analysis of ultrasound, MRI and pathologic specimen B.C. Devenney-Cakir, E. Kuligowska; Boston, MA/US (brooke.devenney-cakir@bmc.org)

Learning Objectives: To illustrate the spectrum of radiologic findings in gestational trophoblastic disease. To demonstrate the effectiveness of ultrasound and MRI in the characterization of gestational trophoblastic disease. To describe the correlation between imaging and pathologic analyses.Background: Gestational trophoblastic disease is a spectrum of neoplasm that exhibits a wide range of biologic behavior and malignant potential. Gestational trophoblastic disease includes hydatidiform mole, invasive mole, choriocarcinoma, and placental site trophoblastic tumor. The latter three have malignant potential thereby increasing the significance of a correct and timely diagnosis. In this exhibit, we will demonstrate the presence of key imaging features that aid in the diagnosis of gestational trophoblastic disease, those that require further evaluation with MRI or direct tissue sampling, and those that prove to be pitfalls in diagnosis.Imaging Findings: Correlation between ultrasound, MRI and pathologic analysis of nine patients demonstrate both the significant imaging features of gestational trophoblastic disease as well as the pitfalls in diagnosis. Given the spectrum of pathologic features, correlation between ultrasound, MRI and ultimate pathologic analysis illustrate key features that aid in the correct classification or exclusion of gestational trophoblastic disease.Conclusion: Retrospective review of a series of patients demonstrates key imaging findings pathognomonic to the presence of gestational trophoblastic disease, as well as findings requiring further evaluation with MRI and/or tissue analysis. Series findings demonstrate the utility of MRI evaluation in the diagnosis and treatment of certain cases of gestational trophoblastic disease.

C-331 Pelvic imaging after gynecological cancer treatment C. Campos, T.M. Cunha, A. Félix; Lisbon/PT (csofiareis@yahoo.com)

Learning Objectives: To describe and to illustrate the features of anatomic changes in the pelvis after treatment of gynecological cancer.Background: Treatment procedures of cervical, endometrial and ovarian cancers include surgery, radiation therapy and chemotherapy. Knowledge of treatment-related changes in the pelvis is of great importance for accurate interpretation of follow-up computed tomography (CT) and magnetic resonance (MR) images.Imaging Findings: Postsurgical changes in the pelvis are related with the surgical

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procedure and the extent of the resection. After conization, extensive shortening and incompetence of the cervix may occur. The CT and MR appearances of the central pelvis is similar after total and radical hysterectomy, with the absence of the uterus and a linear soft tissue configuration of the vaginal cuff. Metallic clips along the pelvic sidewall can be detected at the site of lymph node dissection. After total exenteration, the pelvis is devoid of the bladder, urethra, genitalia and rectum; and the patient has a urinary diversion and a colostomy. Postradiation changes include decreased size of the uterus and ovaries, poor definition/irregularity of the parametria and the classic changes of the intestinal and urinary tract, mainly findings of inflammation/edema are seen. Chemotherapy induces signs of intratumoral necrosis, and fibrosis with extensive foreign body reaction, in a completely successful response.Conclusion: CT and MR are the primary modalities in follow-up of patients with gynecological cancer. Effective use of these modalities, for evaluation of patients who have undergone gynecological cancer therapy, requires familiarity with the common features of treatment-related changes in the pelvis.

C-332 Vulval and vaginal lesions: Imaging features with clinical and pathologic correlation J.-P. Akakpo, Y. Badachi, B. Lauratet, C. Genestie, F. Capron, J. Lefranc, P. Grenier; Paris/FR (jeanpaulakakpo@wanadoo.fr)

Learning Objectives: To illustrate the spectrum of MRI and/or CT scan features of vulval and vaginal primary malignant or benign lesions. To correlate imaging findings with clinical and pathologic data. To provide examples of differential.Background: Vulval and vaginal primary carcinoma are uncommon. A total of 25 patients underwent MR and/or CT scan for primary vulval and vaginal malignant tu-mours; aother 10 underwent MRI for benign or inflammatory lesions including vaginal Gartner cyst, vaginal or vulval endometriosis or labial cellulitis. Imaging findings were retrospectively reviewed. We analysed the morphologic aspects of the tumours (size, margins,deep extension), pelvic organ involvement and lymph nodes.Imaging Findings: Vulval and vaginal carcinoma are well defined on T2-weighted MRI showing intermediate-to-high signal intensity.They are also well defined after IV gadolinium administration on fat-suppressed T1W MR imaging as relatively high enhancing mass. The deep invasion of the tumours to the urethra, anus and pelvic muscles are well assessed. Vaginal Gartner cyst, vaginal or vulval endometriosis and labial cellulitis are also well defined on MRI.Conclusion: Malignant lesions of the vulva and vagina account for less than 5% of all genital tract cancer.The most important prognostic variables are the tumour diameter and the number of positive groin nodes.The size of the lesion is highly relevant to the status of the groin nodes. MR is the exam of choice to identify deep tumour extension, to delineate local invasion.

C-333 How to improve your technique and perform an almost painless hysterosalpingography A. Ghiatas, M. Gakis, A. Kateri; Athens/GR (abraham@otenet.gr)

Learning Objectives: To outline the appropriate steps that should be considered in order to avoid or at least minimize the pain produced by the procedure without compromizing the quality of the study.Background: Hysterosalpingography remains one of the significant imaging pro-cedures in the evaluation of the female infertility but is associated with pain and the majority of the patients undergo this procedure with great fear for pain.Procedure Details: In the past two years, in our department, we have performed almost 5000 hysterosalpingograms and from this group we had randomly selected 1800 patients where we applied our technique which was mainly focused on the reduction of the pain producing maneuvers such as handling of the vaginal specu-lum, immobilization and traction of cervix, introduction of contrast media into the uterine cavity and salpinges.Conclusion: A significant percentage (90%) of our patients reported none or minimal discomfort during the performance of hysterosalpingography, and a small degree of discomfort was reported from the rest of the patients from our group.

C-334 Uterine and tubal imaging: Correlation of histerosalpingography, ultrasound and hysteroscopy findings M.R. Cozcolluela, L.A. Sanz, H. Gómez, J. Aramburu, L. Miranda, M.T. Martinez-Berganza, J.M. Mellado, H. Yagüe; Tudela/ES

Learning Objectives: To present an illustrated review of imaging findings detected at histerosalpingography, ultrasound and hysteroscopy in cases of uterine pathology, tubal abnormalities and anatomic variants.

Background: Histerosalpingography (HSG) is the most commonly used technique indicated for the study of the uterine cavity in the evaluation of infertility. It has traditionally been considered the gold standard for assessment of Fallopian tubes, giving information about their patency and morphology. Ultrasound (US) is almost always the first modality used in the radiologic work-up of endometrial disease, and hysteroscopy, performed by a gynecologist, is considered the gold standard in uterine cavity diseases.Imaging Findings: We establish a complete correlation between HSG, US and hysteroscopy findings. Uterine abnormalities detected at HSG include congenital abnormalities of uterine shape (unicornuate uterus, bicornuate uterus, arcuate uterus, etc.), polyps, leiomyomas, surgical changes, synechiae, adenomyosis, and missed abortion (retained products of conception). Tubal abnormalities include cornual spasm, tubal occlusion, salpingitis isthmica nodosa, polyps, hydrosalpinx, peritubal adhesions, and post-surgical changes. There are also non-pathologic findings and anatomical variants detected at HSG: air bubbles, uterine folds, cervical glands, etc.Conclusion: Histerosalpingography plays an important role in the characterisation of uterine and tubal pathology and correlates with ultrasound and hysteroscopy findings.

C-335 MR features of uterine leiomyomas with pathologic correlation P. Alves, T.M. Cunha, A. Félix; Lisbon/PT (tojais.pedro@gmail.com)

Learning Objectives: To illustrate the spectrum of MR features of uterine leiomyo-mas in correlation with pathological findings.Background: Leiomyomas are the most frequent type of uterine neoplasm and are composed of smooth muscle and fibrous support tissue. Histologically four subtypes are defined: cellular, epithelioid, bizarre and lipoleiomyoma. Regarding topography they are classified as submucous, intramural, subserous or pedunculated. Clinical features depend on the size and location of the tumor, while MR features differ according to whether they exhibit degeneration or not. MR allows accurate evalu-ation of the number, size and location of the tumors, as well as distinction from adnexal lesions, an important advantage over sonography in patients with large body habitus and/or unfavorable tumor locations for the US probe. In the differential diagnosis, MR is useful in the distinction from adenomiosis, being the identification of sarcomatous degeneration more problematic.Imaging Findings: Uterine leiomyomas are typically demonstrated as low-signal intensity lesions on T2WI and intermediate signal intensity on T1WI due to the extensive hyalinization encountered pathologically. If degenerative changes are present leiomyomas may show a variable appearance and signal intensity, reflecting the different pathological features. Also, unusual types of leiomyomas as well as unusual growth patterns may have characteristic appearances on MR.Conclusion: MR allows estimation of the number, features and localization of leiomyomas. Knowledge of the different appearances of degeneration as well as other less common characteristics helps in an accurate diagnosis. Cautious judg-ment should be exercised in evaluation of malignant transformation.

C-336 MR imaging for the differential diagnosis of dilated fallopian tubes K. Tamai, T. Koyama, N. Morisawa, K. Fujimoto, T. Ikeuchi, N. Satogami, K. Togashi; Kyoto/JP

Learning Objectives: To review MR and clinical features in various conditions causing dilated fallopian tubes with emphasis on key MR features for the dif-ferential diagnosis.Background: Dilated fallopian tubes can be caused by various conditions includ-ing inflammation, endometriosis, emergent conditions such as ectopic pregnancy and torsion, and neoplasms. Since the management of the patients differs in each condition, the establishment of accurate diagnosis is important. In this exhibit, we review MR and clinical features in various conditions causing dilated fallopian tubes and discuss the usefulness of MRI in the differential diagnosis.Imaging Findings: Dilated fallopian tubes presents as a fluid-filled structure with a folded and tortuous appearance on MRI. The recognition of their characteristic serpentine shape helps distinction from ovarian masses. Tuboovarian abscess typically shows an irregularly-thickened enhanced wall associated with stranding of the pelvic fat. Hematosalpinx can be associated with endometriosis and shows high signal intensity on T1WI. In tubal pregnancy, dilated tube contains fresh hematoma of distinct low intensity on T2WI. The presence of gestational sac-like structure and enhanced tubal wall can allow specific diagnosis of this condition. Isolated tubal torsion, which is an uncommon cause of emergency, may manifest as twisted and swollen tubes on MRI. The presence of solid components in dilated tube is an important sign for tubal carcinomas. Clinical symptoms such as vaginal discharge and pelvic pain may also suggest these tumors.

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Conclusion: Knowledge of MR features in various conditions causing dilated fallopian tubes facilitates establishing accurate diagnosis and determining ap-propriate management.

C-337 Secondary tumors in gynecologic organs: Usual, unusual imaging manifestations and pitfalls K. Matsuzaki, M. Takeuchi, H. Nishitani; Tokushima/JP (kenji@clin.med.tokushima-u.ac.jp)

Learning Objectives: To demonstrate imaging manifestations of various second-ary malignant tumors in gynecologic organs, and to differentiate from primary gynecologic tumors.Background: Ovarian metastases are common secondary tumors in the female pelvis, and uterus or vagina may also be involved. Pathways from primary sites are various such as hematogenous or lymphatic metastases, trans-coelomic dis-semination, and direct or trans-vaginal invasion.Imaging Findings: Ovarian metastasis: Bilaterality may suggest metastases, but primary serous tumors may also appear as bilateral masses. Ovarian mass with liver or lung metastases without ascites or carcinomatous peritonitis may suggest metastasis. FDG-PET or whole body diffusion-weighted MR images may be useful to detect occult primary malignancy. Most of ovarian mucinous tumors associated with pseudomyxoma peritonei are metastasis from primary appendiceal tumors, which are often small and easily overlooked. Krukenberg tumors are often detected before the primary small gastric cancer, and intense contrast-enhancement of the tumor with ring-enhanced cyst may be the diagnostic clue. Ovarian metastasis may show hormonal activity and cause uterine enlargement. Uterine metastasis is relatively rare and may represent as myometrial masses, but infiltrative involvement of breast cancer or lymphoma may cause diffuse uterine myometrial enlargement. Trans-vaginal submucosal spread of vulvar melanomas may cause vaginal or cervical mass mimicking primary tumors. Dynamic CT is useful in detecting hypervascular vaginal metastases from renal or breast cancers.Conclusion: To recognize usual and unusual patterns of tumor spread is important to differentiate primary gynecologic tumors from secondary involvement for the adequate surgical procedure.

C-338 Significance of diffusion-weighted imaging for the diagnosis of ovarian neoplasms with pathologic correlation S. Kakite, S. Fujii, K. Nishihara, Y. Kanasaki, M. Ishibashi, T. Ogawa; Yonago/JP

Learning Objectives: 1) To illustrate diffusion-weighted (DW) imaging findings of ovarian neoplasms with pathologic correlation. 2) To discuss the advantages and limitations of DW imaging for clarifying the significance of DW imaging for the evaluation of ovarian neoplasms.Background: DW imaging has been gradually accepted for the detection and characterization of extracranial focal lesions. In general, malignant lesions tend to show abnormal signal intensity reflecting increased cellularity. In gynecological imaging, it is not sufficiently clarified how DW imaging plays a role. This review demonstrates the knowledge of its advantages and limitations for evaluating ovar-ian neoplasms.Imaging Findings : Most malignant ovarian neoplasms and mature cystic terato-mas show strong signal intensity more than or equal to that of nerve root on DW imaging, while most benign ovarian neoplasms with solid portions such as fibromas do not show strong signal intensity. Besides, half of the endometrial cysts include portions of strong signal intensity. The locations of strong signal intensity on DW imaging are as follows: solid portions of malignant ovarian neoplasms, keratinoid substances, Rokitansky nodule and fat balls of mature cystic teratomas, loculus composed of viscous fluid of mucinous adenomas and clots, the portions of polypoid endometriosis and decidual change of endometrial cysts.Conclusion: DW imaging is useful for detecting the solid portions of malignant neoplasms, but has a limited role in the differentiation of benign from malignant conditions of the ovary, such as malignant tumor arising from endometrial cysts. Thus, the knowledge of DW imaging is essential for avoiding misinterpretation.

C-339 Spectrum of findings on Mullerian duct anomalies at MRI P. Paolantonio, R. Ferrari, M. Rengo, P. Lucchesi, F. Vecchietti, A. Laghi; Latina/IT (paolantoniopasquale@hotmail.com)

Learning Objectives: To illustrate some crucial MRI technical features for the evaluation of normal uterine morphology and mullerian duct anomalies. To show the spectrum of findings of several mullerian duct anomalies on MRI. To illustrate

MRI findings useful in predicting the clinical impact of uterine anomalies in terms of infertility or risk of miscarriage. To illustrate MRI findings useful for the assess-ment of treatment regimens.Background: Since 1988, the American Fertility Society (AFS) established a clas-sification of uterine malformations. Because defects of the mullerian ducts are the result of a spectrum of non-fusion of mullerian ducts, deficient development and/or defective canalization of the uterine cavity, the process may become arrested at any point in development. A complete assessment of uterine anatomy is mandatory in order to evaluate the impact of uterine malformation on women fertility and also to plan the optimal strategy of treatment.Imaging Findings: In this exhibit, we describe an optimized MRI protocol including high-resolution T2-weighted TSE sequence, acquired on dedicated oblique planes for the evaluation of uterine morphology. We describe MR findings of several mul-lerian duct anomalies according to the AFS classification, with emphasis on different subtypes of septate uterus, describing findings useful to predict risk of recurrent miscarriage and to programme histeroscopical surgical treatment.Conclusion: MRI is a safe, non-invasive and ionizing-free method for the diagnosis of uterine anomalies. MRI allows a complete evaluation of uterine morphology, useful in the planning of surgical approach.

C-340 MRI pharmacokinetic modelling of treatment effects in patients with ovarian hyperestimulation syndrome L. Marti-Bonmati, R. Sanz; Valencia/ES (luis.marti@uv.es)

Purpose: To study the effects of cabergoline (Cb2) in the treatment of patients with ovarian hyperestimulation syndrome (OHSS) by dynamic contrast-enhanced magnetic resonance (DCE-MR) pharmacokinetic modeling.Methods and Materials: 20 oocyte donor women (10 with cabergoline treatment and 10 with placebo) under risk of developing OHSS underwent two 1.5 T DCE-MRI of the ovaries with 2 days interval. The MR sequence was a gradient echo (TR 71.3 ms, TE 1.13 ms, flip angle 60º, voxel size 0.74x0.74x6 mm, time resolution 4.4 s). Contrast agent was injected intravenously as a bolus (0.2 ml/kg at 4 ml/s, 40 ml saline flush). In the pharmacokinetic model four parameters were studied: perme-ability (Ktrans, ml/min/100 ml), extraction ratio (kep, ml/min/100 ml), extravascular extracellular space fraction ( e, %) and vascular space fraction ( p).Results: For the placebo group, Ktrans was 20.2 9.6 at MR1 and 42 9.7 at MR2 (p 0.001), kep was 95.4 55.1 at MR1 and 96.9 14.7 at MR2 (p=0.937), e was 38.6 10.6 at MR1 and 46.6 5.8 at MR2 (p=0.064) and p was 30.3 12.0 at MR1 and 22.5 5.2 at MR2 (p=0.093). For the treated group, Ktrans was 20.3 6.8 at MR1 and 28.6 10.4 at MR2 (p=0.078), kep was 68.7 12.8 (p=0.05), e was 37.3 6.2 at MR1 and 41.0 13.1 at MR2 (p=0.476) and p was 22.9 3.4 at MR1 and 24.0 1.8 at MR2 (p=0.419). Statistical analysis shows a significant Ktrans increase at MR2 only for the placebo group.Conclusion: Pharmacokinetic parameters are surrogate markers of treatment. A significant increase in permeability was found in the placebo group, while Cb2 treatment shows stabilization of the vascular compartment.

C-341 Postpartum haemorrhage embolization with resorbable agents: Long term clinical results over fertility and menstrual function in 119 patients G. Gaia, P. Chabrot, R. Botchorishvili, L. Cassagnes, D. Gallot, A. Calcagno, M. Canis, G. Mage, L. Boyer; Clermont Ferrand/FR (pchabrot@chu-clermontferrand.fr)

Purpose: To evaluate our long term clinical results and fertility after postpartum haemorrhage treated by embolization with resorbable agents.Methods and Materials: Retrospective monocentric study including 119 consecu-tive patients who underwent gelatine sponge embolization for severe postpartum hemorrhage (1999-2006). 116 obstetrical chart reviews were collected, and 77 telephone interviews conducted. For 33 unreachable patients, the data concerning subsequent obstetric or gynaecologic long-term outcomes were analyzed from their medical records. The mean follow-up was 46.4 months (12 to 84).Results: 31 patients out of 110 (28%) reported changes in the frequency and amount of menses at the end of the follow-up. 6 patients out of 110 (5%) reported amenorrhea and diffuse uterine sinechiae (hysteroscopy); among them, 1 had uterine hypotrophy, small ovaries and menopausal level of oestrogen, 1 got pregnant after surgical treatment, 3 patients who desired a pregnancy were recommended against by their gynaecologist. 29 patients desired to get pregnant, among whom 3 were recommended against by their gynaecologist. 17 (65%) patients reported a total of 19 pregnancies with 11 months mean conception delay (6-36). One patient who did not plan became pregnant. 3 pregnancies out of 18 (16.6%) were complicated by a further postpartum hemorrhage requiring embolization, and one 12 weeks miscarriage was reported. All full-term newborns were healthy.

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Conclusion: Resorbable agents’ embolization is effective with few long term complications but the rate of sinechiae, amenorrhea and recurrence of PPH must be kept in mind.

C-342 64-row MDCT virtual hysteroscopy P. Carrascosa1, M. Baronio2, C.M. Capuñay3, E. Martín López3, J. Vallejos3, C. Sueldo2, S. Papier2; 1Vicente Lopez/AR, 2Buenos Aires/AR, 3Vicente López/AR (investigacion@diagnosticomaipu.com.ar)

Purpose: To determine the performance of 64-row MDCT virtual hysteroscopy (VH) in the evaluation of patients with uterine or gynecologic disorders and to compare the results with conventional X-ray hysterosalpingography (HSG).Methods and Materials: Twenty patients (mean age 35, 36 years old, 3.77) were studied with HSG and VH in the same day. VH exams were carried out with a 64 row-CT scanner (Philips Medical Systems) using 0.6-mm slice thickness, 0.3-mm reconstruction interval, 120 kV; 200 mAs; gantry rotation 0.4 s. Ten mL of diluted contrast (1 mL of iodide contrast and 9 mL of saline solution) were administered into the uterine cavity. X-ray HSGs were performed with standard technique. Findings of both methods were compared. The radiation doses were calculated in all the patients for both studies. Sensitivity (S), specificity (Sp), positive predictive value (PPV) and negative predictive value (NPV) of each procedure were calculated using the exact binomial method in a per-lesion analysis.Results: There was a significant radiation dose reduction of 2.71 mSv (p 0.001; 95% CI= 2.61-2.84) in 64-row MSCT-H when compared to HSG. For uterine pathol-ogy S, Sp, PPV and NPV were 100, 85.71, 84.61 and 100%, respectively whereas for fallopian tubes pathology was 100% for all items.Conclusion: MDCT-VH presents good diagnostic accuracy in comparison with HSG, showing better patient tolerance and less radiation dose. MDCT-VH gave 2D, 3D and endoscopic images with more information detail than HSG due to a greater spatial resolution.

C-343 PET-CT in recurrent ovarian cancer M.S. Lenhard, T.R. Johnson, C. Kuemper, R. Linke, N. Ditsch, A. Burges; Munich/DE (Thorsten.Johnson@med.uni-muenchen.de)

Purpose: To assess the diagnostic value of PET-CT in diagnosis and therapy planning of recurrent ovarian cancer.Methods and Materials: 26 patients who had received a PET-CT for suspicion of recurrent ovarian cancer were included in a retrospective analysis. PET-CT was performed on a Philips Gemini System one hour after administration of 200 MBq fluorodesoxyglucose covering the body from the neck to the thighs. The reports of PET-CT and surgery and the patient records were reviewed to analyze the accuracy of PET-CT in the diagnosis of recurrence, the prediction of full resectability and the localization of intraperitoneal spread.Results: A relapse was found in 25 of 26 patients. There were no false-positive and no false-negative results, yielding full sensitivity and specificity with 95% confidence intervals of 86-100% and 19-100%, respectively. In 12 cases there was an indication for laparatomy, 11 with complete resectability suspected in PET-CT. Tumor tissue was removed and confirmed histologically in all operated patients. In 9 patients, the tumor could be removed without macroscopic rest, while only an incomplete resection was possible in 2 cases. Thus, sensitivity and specificity of PET-CT in the identification of fully resectable patients were 100 and 33%. Regarding peritoneal carcinosis, PET-CT had a limited sensitivity of only 60%.Conclusion: PET-CT offers a reliable detection of recurrent ovarian cancer. Although the diagnostic accuracy in the prediction of full resectability is limited, the modality can assist surgical planning by identifying sites of intraperitoneal involvement.

C-344 3D transvaginal sonography in evaluation of combined endometrium and miometrium pathology before hysteroresection V.V. Gazhonova, A. Devyatovskaya, T. Kurganskaya, T. Smirnova; Moscow/RU (vx969@mail.ru)

Purpose: To determine the possibilities of 3D Transvaginal (TV) sonography in preoperative assessment of endometrium pathology and to correlate the findings with hysteroscopic and microscopic data.Methods and Materials: 65 women with symptomatic endometrium pathology in combination with miometrium pathology were examined before hysteroscopy. 3D TVS was performed. Multiplanar images of the uterus were created. Preoperative location of the polyps in relationship with internal surface of the uterine cavity was assessed. US results were compared with hysteroscopic and pathomorphology data.

Results: Surgical management after 3D TVS examination was changed in 9% of cases. 3D coronal images allowed better location of the endometrium polyps and submucous myomas. 3D TVS results correlated with hysteroscopy in 91% of cases vs. 79% on 2D TVS. In comparison with microscopic data of the uterus, 3D TVS were superior to 2D TVS in differentiation of the type of endometrium pathology 86% vs. 73% on 2D TVS.Conclusion: 3D TVS is a useful complement to 2D TVS for preoperative assess-ment of endometrium pathology. 3D TVS provided precise evaluation of the polyp thus enabling adequate polypectomy. Accurate evaluation of the endometrium pathology on 3D TVS can decrease the possibilities of relapses thus reducing the quantity of repeated operations.

C-345 Diffusion-weighted echo-planar 3 T MRI and ADC mapping in the differential diagnosis of uterine masses: Usefulness for the detection of malignant tumors T. Namimoto, K. Awai, T. Nakaura, Y. Yanaga, Y. Yamashita; Kumamoto/JP

Purpose: The purpose of this study was to compare the apparent diffusion coefficient (ADC) values calculated from diffusion-weighted MRI (DWI) of malignant and benign uterine masses and to test whether the ADC can differentiate between them.Methods and Materials: DWI was performed in 61 patients with uterine masses (34 leiomyomas, 12 cervical carcinomas, 9 corpus carcinomas, 4 corpus sarcomas, and 4 endometrial polyps). We measured the ADC on a 3 T MR system (Achieva-3 T, Philips) with b-factors of 0, 800 or 1000 s/ mm2 using single-shot echo-planar DWI and a parallel imaging technique. The areas of highest signal intensity on EP-DWI (b=800 or 1000 s/mm2) and the mean ADC values within the cystic component were evaluated.Results: The mean ADC value for leiomyomas was 1.15 0.25×10−3 mm2/s; for cervical carcinomas, 0.94 0.21×10−3 mm2/s; for corpus carcinomas, 0.76 0.11×10−3 mm2/s; for corpus sarcoma, 0.97 0.08×10−3 mm2/s; and for endo-metrial polyps, 0.94 0.08×10−3 mm2/s (normal cervix tissue, 1.43 0.27×10−3 mm2/s). The ADC of malignant masses was significantly lower than of benign masses (t-test, p 0.01).Conclusion: Our preliminary results indicate that the ADC value may add useful information to the differential diagnosis of malignant and benign uterine masses.

C-346 Dynamic contrast-enhanced MR imaging of uterine cervical cancer: Tumor angiogenesis analysis and correlations with histomorphological tumor markers R. Domínguez-Oronoz, S. Gispert, V. Pineda, X. Merino, A. García, R. Vergés; Barcelona/ES (16966rdo@comb.es)

Purpose: To correlate contrast enhancement curve findings obtained by dy-namic MR study with various markers of tumor angiogenesis to establish MR prognostic factors.Methods and Materials: We studied 29 patients with uterine cervical cancer diag-nosed from 2000 to 2005. Dynamic contrast-enhanced MR imaging was performed to obtain first-pass SI/time curves (% slope uptake), enhancement ratio and types of curves according to wash-out behaviour (3 types). We correlated these values with results from determination of molecular angiogenesis factors (VEGF, KDR, bcl2 and p53) in biopsied tumor tissue specimens. We also correlated the enhancement patterns with tumor volumes.Results: The tumor volumes ranged from 2.4 to 220 ml (mean=57.2 ml). 19 of 29 patients showed a plateau curve, 9 of 29 biphasic and monophasic curve in only one case. No significant correlation was found between the enhancement curves and tumoral angiogenesis markers. A significant correlation between the tumoral volume and wash-out behaviour was found. The mean volume was 91.52 ml in patients with biphasic curve and 40.34 ml in patients with plateau curve (r of Pearson=0.466, p=0.022).Conclusion: Higher volumes tumors showed significant wash-out behaviour (bi-phasic curves). No significant correlation was found between enhancement curve findings (slope uptake and curve type) with tumoral angiogenesis markers evaluated (VEGF, KDR, bcl2 and p53). Further studies are necessary to correlate dynamic MR studies with clinical evolution in order to establish MR prognostic factors.

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C-347 Usefulness of vaginal distention with aqueous jelly to improve visibility of pelvic anatomical structures on MRI C. Marcotte, S. Novellas, M. Fournol, T. Caramella, P. Chevallier; Nice/FR (marcotte.c@free.fr)

Purpose: To evaluate the usefulness of vaginal distention with aqueous jelly to improve visibility of pelvic anatomical structures on MRI.Methods and Materials: Monocentric prospective study investigating 49 patients with a pelvic MRI. The protocol included axial and sagittal T2-weighted slices, before and after injection into the vagina of sterile jelly for ultrasonography. 8 anatomical points were analysed and quoted, according to their visibility from 1 (excellent) to 4 (not seen) by 2 junior and 2 senior radiologists. Each exam was analysed twice by each reader with an interval of 2 weeks. Performance was estimated by the difference of the visibility index on each point.Results: The accuracy of the visualisation of all anatomical structures was sig-nificantly improved (p 0.003). It was excellent for anterior and posterior vaginal fornices (delta=2.4 and 1.7), good for the vesicovaginal septum, rectovaginal septum and Douglas pouch (1.4, 1.1 and 0.9) and medium for the cervical stroma, outer contours of the cervix and torus uterinus (0.8, 0.7 and 1.7 points, respectively). This improvement was more important for junior than for senior radiologists.Conclusion: The intravaginal injection of jelly for ultrasonography during pelvic MRI is a fast, inexpensive, easy and well-tolerated method. It can improve vis-ibility of some important pelvic anatomical structures and should be performed systematically.

C-348 Characterization of parametrium infiltration by MR imaging after preoperative radiotherapy in invasive carcinoma of the uterine cervix N.A. Rubtsova, S.A. Sedykh, E.G. Novikova, L.V. Demidova, O.B. Dubovetskaya; Moscow/RU (RNA17@yandex.ru)

Purpose: The aim was to assess the value of magnetic resonance imaging (MRI) in the detection of residual tumour and differentiation of parametrium infiltration after preoperative radiotherapy in patients with invasive carcinoma of the uterine cervix.Methods and Materials: From 2006 to 2007, 25 women with stage T2bN0-1M0 cervical carcinoma underwent MRI of the pelvis, before and after preoperative radiotherapy. MR imaging was performed at 1.5 T (GE Signa) using a flexible 4 channel torso coil. Histopathology was available in all subjects. T2W FRFSE images were acquired sagittally, axially and obliquely, T1W FSE before and after Gd + fat suppression as determined clinically.Results: Histology revealed residual tumour extension into the parametrial tissue in 8 (32%) patients receiving preoperative radiotherapy for cervical carcinoma. MRI showed parametrium infiltration in 9 cases, which were classified as tumour extension. 2 of 9 cases were over diagnosed, when parametrial tissue was oede-mata and did not have a clear border line with tumour. 15 cases were true negative because morphological examination determined considerable damage of tumour tissue (IV grade of patomorphosis). 1 case was under diagnosed. The sensitivity, specificity and accuracy of MRI for the characterization of parametrium infiltration were 87.5%, 88.2% and 88%, respectively.Conclusion: These results demonstrate the potential of MR imaging in assess-ment of parametrium infiltration. However, a larger number of cases are required in order to study the evaluation of tumour extension into the parametrial tissue after radiotherapy.

C-349 The ovarian cystic masses: Evaluation with MRI N.V. Marchenko, G.E. Trufanov, A.V. Mischenko, I.A. Trofimenko; St. Petersburg/RU (gmv2006@mail.ru)

Purpose: To assess the value of MRI images in the examination of the ovarian cystic masses.Methods and Materials: We examined 40 patients with different adnexal cystic masses with and without contrast enhancement (1.5 T MRI unit). We assessed T1- and T2-weighted images with and without fat suppression.Results: The dermoid cysts and hemorrhagic masses (corpus luteum cysts) demonstrated similar MRI features: high signal intensity on the T1-weighted im-ages and variable signal intensity on the T2-weighted images. The chemical shift images provided exact differentiation between fat and hemorrhagic compounds. The dermoid cysts (8) contained different tissues (teeth, fat, hair, and fluid) and tended to be high in signal on both T1- and T2-weighted images. The fatty elements displayed high signal intensity on T1- and T2 weighted images. Sequences with fat

saturation provided clear difference between fat and hemorrhagic foci: fat showed loss of signal and blood remained hyperintense. Besides, these cases included five examples of ovarian apoplexy with hyperintense area of hemorrhage on T1-weighted images. The ovarian cystadenomas (10) were visualized in multiplanar fashion to evaluate involvement of neighboring fat and organs. Contrast-enhanced study assisted the evaluation of lesion extent and involvement of surrounding structures and was crucial for planning following treatment. In 17 cases we evalu-ated follicular cysts in dynamic, they showed sharp regular borders and signal intensity typical to fluid.Conclusion: MRI may be applied as a highly informative method providing vi-sualization of different cystic masses with the identification of their content and evaluation of their origin and extent.

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Kidney

C-350 A review of percutaneous nephrolithotomy: Procedure planning, technical considerations and postprocedure evaluation E. Ward, A. Snow, J. O’Brien, R. Browne; Co Dublin/IE (emily.ward@amnch.ie)

Learning Objectives: To define the clinical indications for percutaneous nephroli-thotomy (PCNL). To assess the factors involved in optimal track planning. To present and illustrate technical considerations to aid collecting system access, ensure track stability and avoid complications.Background: Over 100 cases of PCNL performed at our institution from July 2005-July 2007 were reviewed. Patients underwent pre-procedure intravenous urography and/or non-contrast CT examination to facilitate optimum track planning. PCNL was performed as a two-part procedure in all cases. Collecting system access and track dilatation to 10 F in size was performed under conscious sedation in the radiology department. Further track dilatation to 28 F and nephrolithotomy was performed under general anaesthesia in the operating theatre with combined radiological and urological inputs. Stone clearance was assessed fluoroscopically at the time of procedure and with subsequent plain film radiography.Procedure Details: 1. Pre-procedure imaging and assessment. 2. Anatomical con-siderations for optimal track planning. 3. Review of indications. 4. Need for multiple tracks, including upper pole access. 5. Collecting system access techniques and trouble-shooting tips. 6. Post-procedure evaluation.Conclusion: PCNL remains the treatment of choice for renal staghorn calculi or calculi refractory to lithotripsy. Appropriate pre-procedure imaging and track planning will facilitate maximal stone clearance. Technical considerations are important to allow system access, ensure track stability and avoid potential complications.

C-351 Evaluation of renal veins using 64-slice MDCT before laproscopic donor nephrectomy: Anatomy, variants and techniques H. Patel, M. Doctor, A.J. Shah, G. Tomar, M. Patel; Ahmedabad/IN (hemantmri@gmail.com)

Learning Objectives: 1. To understand the changing application of CT angiogra-phy for renal donor evaluation. 2. To know importance of venous mapping before laproscopic donor nephrectomy. 3. To describe the normal anatomy of renal veins and their variants. 4. To review the CT angiography technical parameters to be used and which technique can be used.Background: MDCT is rapidly becoming the gold standard for renal donor evalu-ation. Apart from arterial anatomy it is equally important to know detailed venous vascular anatomy. In this exhibit we will describe anatomy and variants of renal veins, techniques of CT angiography of renal veins-MIP-MPR-3DVRT, and the advantages of CT angiography compared to the existing conventional catheter angiography. Between November 2006 and August 2007, 74 healthy subjects were evaluated for renal donor work up. Clinical cases, variants, mimicks and operative correlation are described and illustrated.Imaging Findings: MDCT demonstrated renal vein mapping very precisely. It was also possible to demonstrate adrenal and gonadal veins in all cases. MIP was the preferred method for better delineation of veins. In our series of 74 case studies, 53 had normal renal veins and 21 had various variants including multiple renal veins, retroaortic and circumaortic renal veins. All cases were correlated well with operative findings.Conclusion: 1. Accurate delineation of renal vascular architecture is extremely important in presurgical planning for laproscopic donor nephrectomy. 2. Renal ve-nous variations are very common and with the help of 64 slice MDCT, using proper technical parameters and postprocessing techniques, it is possible to demonstrate renal venous anatomy more efficiently.

C-352 Usefulness of contrast-enhanced ultrasonography in the evaluation of complex renal cysts E. Ballesteros Gomiz, A. Malet Munté, J. Puig Domingo, A. Darnell Martin, A. Alguersuari Cabiscol, J.L. González Sala; Sabadell/ES (eva.gomiz@gmail.com)

Learning Objectives: To show the usefulness of second-generation contrast agents in the ultrasonographic examination of complex renal cysts using the Bosniak classification.Background: In renal cysts, the likelihood of malignancy is assessed using the

Bosniak classification, traditionally based on intravenous contrast-enhanced CT. Re-cent studies show that gadolinium-enhanced MRI can also be used for the Bosniak classification with very similar results to contrast-enhanced CT. Ultrasonography with intravenous contrast agents has been recently introduced for the evaluation of the likelihood of malignancy of complex renal cysts and the results are equivalent to those of CT and MRI. Moreover, unlike those used in CT and MRI, ultrasonographic contrast agents involve no risks for patients with altered renal function.Imaging Findings: We show illustrative examples of complex renal cysts studied with second-generation ultrasonographic contrast agents, categorizing each ac-cording to the Bosniak classification: cysts with echogenic material inside that does not enhance, both with and without calcifications (Bosniak II and IIF); cysts with thickened septa that enhance (Bosniak III); and cysts with parietal nodules that enhance (Bosniak IV). In categories III and IV, we also show the correlation with intravenous contrast-enhanced CT.Conclusion: Ultrasonography with intravenous administration of second-generation contrast agents is very useful for the Bosniak classification of complex renal cysts. It does not require the use of ionizing radiation and involves no risks for patients with altered renal function.

C-353 Laparoscopic nephrectomy: A radiologist’s guide M.A. Goldstein1, S.K. Lapsia1, A. Golash1, S. Ghai2; 1Newcastle-under-Lyme/UK, 2Toronto, ON/CA (goldsteinmark@yahoo.co.uk)

Learning Objectives: 1) To understand the anatomy and techniques used. 2) To understand the importance of pre-operative imaging. 3) Recognise the commonly occurring complications in the immediate post-operative period.Background: Laparoscopic nephrectomy is a technique that has been increas-ingly performed since the mid 1990s typically for removal of a tumour or for renal transplant harvesting. It is a minimally invasive procedure and can be performed as a day case. The procedure may be performed by either via a transperitoneal or a retroperitoneal approach. Our exhibit aims to inform radiologists of the two major techniques used by surgeons, the pre-operative radiological assessment and typical complications in the immediate post-operative period.Imaging Findings: Anatomical diagrams are used to demonstrate the two main laparascopic surgical techniques. Multidetector computed tomography (MDCT) images together with post-processing are used to demonstrate pre-operative radiological assessment which is essential to delineate the exact patient anatomy and in particular the renal parenchyma, vasculature and collecting system. Typical post-operative complications are exhibited classified as renal or extra renal.Conclusion: Radiologists need to understand the techniques used for lapa-roscopic nephrectomy and to identify any anatomical variants essential for pre-operative surgical planning. This will ultimately reduce complication rates and patient morbidity.

C-354 High resolution ultrasonography in the diagnosis of the abnormalities of musculoskeletal system in patients with chronic renal failure M.B. Damasio, A. Tagliafico, C. Martinoli, F. Massarino, L.E. Derchi; Genova/IT (agtag@libero.it)

Learning Objectives: The aim of this pictorial essay is to provide an overview of the pathological changes leading to soft tissue diseases in patients with chronic renal failure; and to describe the high-resolution ultrasonography (US) appearances of the most frequent musculoskeletal (MSK) lesions in patients with CRF.Background: MSK abnormalities are numerous and frequent in patients with (CRF). Radiological protocols for the follow-up of CRF patients are well established and commonly used in clinical practice. Although US is widely used in the study of MSK diseases, the diagnostic possibilities of this technique in assessing soft tissue changes in CRF patients have received relatively poor attention.Procedure Details: This exhibit will use schematic drawings and US images to illustrate the appearance of musculoskeletal disorders in patients with chronic renal diseases for which US examination is indicated. It will include: Dialysis Related Amyloidosis (DRA) with particular emphasis on carpal tunnel syndrome, flexor tendons deposits (amyloid hand) and shoulder pain; soft tissue and periarticular calcifications; crystal deposition arthritis (gout, pseudoguot, calcium oxalate crys-tal deposits, arthropathy associated with hydroxyapatite crystals); tendon tears, including spontaneous tendon ruptures; infections (cellulitis and abscesses, septic bursitis, osteomyelitis); bleeding and ischemic conditions (haematomas and muscle infarctions); and musculoskeletal disorders in renal transplantation. For all of these conditions the most important ethiopathogenetic factors will be discussed.Conclusion: This exhibit will be a guide to make radiologists aware of the multiple pathologic MSK entities which may be evaluated with US in CRF.

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C-355 CT for planning of laparoscopic transplant donor nephrectomy: What to look for, why and how N. Bharwani, P. Skippage, U. Patel; London/UK

Learning Objectives: 1. To understand the role of laparoscopic renal donation. 2. Technique for laparoscopic nephrectomy and its potential hazards. 3. How dedicated renal CT is carried out for pre-surgical planning and how it can inform the surgeon. 4. How to construct 3D images and movie loops for anatomical dem-onstration and planning.Background: Laparoscopic donor nephrectomy is less invasive than open nephrec-tomy, associated with fewer post-operative complications and achieves equivalent results in terms of donor graft function. However, the laparoscopic approach requires more precise information about the renal vascular anatomy due to the limited laparoscopic field of view and potential hazards hidden behind visualised structures. Thus, pre-operative anatomical planning is crucial and is best carried out using CT angiography with 3D reconstruction.Imaging Findings: This exhibit will discuss and illustrate: a) Normal renal anat-omy. b) Common renal arterial and venous variants and how they can influence laparoscopic harvest. c) The method of laparoscopic donor nephrectomy and the potential operative complications. d) Technique for dedicated renal CT and image manipulation to create 3D reconstructions. e) Construction of a clinically relevant report - what the laparoscopist needs to know to avoid complications.Conclusion: Laparoscopic donor nephrectomy is the gold standard technique for renal donation. Optimal planning renal imaging is crucial for preoperative identifica-tion of anatomical variants and potential hazards.

C-356 Diffusion-weighted MR images of urothelial cancer M. Takeuchi, K. Matsuzaki, H. Nishitani; Tokushima/JP (mayumi@clin.med.tokushima-u.ac.jp)

Learning Objectives: To demonstrate the role of high b-value diffusion-weighted MR images (DWI) in detecting the urothelial cancers and in differentiating between benign and malignant pathologies in patients with urinary tract obstruction.Background: 18 F-FDG-PET is useful for malignant tumor detection, but has limitation in evaluating urinary tract neoplasms because of physiological radiotracer excretion. Urothelial cancer (transitional cell carcinoma) may occur as multiple lesions in the urinary tracts, and preoperative detection of all tumors is helpful for adequate surgical planning. Various benign and malignant pathologies may cause urinary tract obstruction, and differentiation of benign obstruction from malignant tumor obstruction is important.Imaging Findings: Urothelial cancer may show very high signal intensity on DWI, while benign urinary tract strictures do not show high signal intensity. Multicentric urothelial cancers at the renal pelvis, ureter and bladder are clearly demonstrated on DWI. In bladder cancers, DWI may be useful especially for detecting small broad-based, flat or wall-thickened tumors. Maximum intensity projection (MIP) of DWI can clearly demonstrate tumor extent in ureteral cancers. MR urography (MRU) in combination with MIP of DWI can provide 3D entire urinary tract imaging with the extension of tumors.Conclusion: DWI may be of value in detecting urothelial cancers and in differentiating between benign and malignant urinary tract obstruction. MRU in combination with DWI can demonstrate the extension of tumors on 3D entire urinary tract imaging.

C-357 Post-operative complications evaluation after laparoscopic cryoablation of small renal masses: Role of multi-detector row computed tomography and magnetic resonance imaging G. Cardone, C. Iabichino, P. Mangili, A. Cestari, L. Nava, G. Guazzoni, G. Balconi; Milan/IT (cardoneg@tin.it)

Learning Objectives: To report the spectrum of post-operative complications in patients treated with laparoscopic cryoablation (LC). To illustrate the magnetic resonance (MR) and multi-detector row tomography (MDCT) findings for post-operative complications in patients treated with LC.Background: Renal LC is a minimally invasive surgical technique for patients with small renal masses. Since it is not possible to document hystopatologically the complete tissue necrosis after cryoablation, an adequate radiological follow-up is mandatory. We report the MDCT and MR imaging findings during the 6 years follow-up of 94 patients who underwent laparoscopic renal cryoablation.Imaging Findings: MR and CT images showed incomplete ischemia of cryolesions in 10% of the cases, with small intralesional enhancement that disappeared in the subsequent controls; 21% of the cases showed a small intralesional haematoma;

97% of the cases showed intralesional low signal intensity foci due to reabsorbable hemostatic material. On 11% of the cases, a small perilesional haematoma was evident at 1 and 3 months after surgery, probably due to dissolution of blood clot. MDCT shows lower contrast resolution compared to MR imaging in the evaluation of peri-lesional collections.Conclusion: The most frequent post-operative complications in patients treated with LC are incomplete ischemia of cryolesion 24 h after surgery and intra-lesional and peri-lesional haematomas. LC is a safe and minimally invasive therapy for small renal masses. MR is an effective tool in the imaging follow-up of renal lesions treated with LC. MDCT can be used as an alternative choice to MR in the evaluation of patients with contraindications to MR imaging.

C-358 The treated kidney: A pictorial review of imaging findings following kidney-directed interventions, short-term and long-term follow-up C. Farinas, S. Carter, M. Patnana, C. Sandler, J. Szklaruk; Houston, TX/US (yeinu@aol.com)

Learning Objectives: To review the indications and techniques of different renal-directed therapies. To learn the CT and MRI appearance of the immediate and long-term follow-up of various renal-directed therapies.Background: There have been recent advances in techniques and an increased utilization of kidney-directed therapy. The most commonly utilized techniques for renal-directed interventions include partial and complete resection, percutaneous nephrostomy, cryoablation, biopsy, ureteral stent placement, and radiofrequency ablation. Computed tomography (CT) and magnetic resonance imaging (MRI) are commonly used for the evaluation of patients with renal disease. Familiarity with the appearance of the liver in the immediate and in the long-term follow-up is essential for accurate image interpretation.Procedure Details: This interactive electronic exhibit will review the current concepts on kidney-directed therapies and the imaging features for immediate and long-term follow-up. The participant will select from a master menu a specific therapy of interest (i.e. partial nephrectomy) and will then be asked to select from a list of topics that include clinical background, immediate imaging features, and long-term imaging features. The clinical background section will include a discus-sion on the technique, indications, success rate, and inclusion criteria for each technique. The exhibit will then illustrate the evolution of the imaging findings for therapeutic response on immediate and long-term imaging studies.Conclusion: This exhibit will teach the participant the indications, techniques, and the immediate and long-term (CT and MRI) imaging features of various kidney-directed therapies.

C-359 Small solid renal cortical tumors: Differentiation with biphasic multi-detector row CT J. Kim, J. Cho, S. Kim; Seoul/KR (mine147@radiol.snu.ac.kr)

Learning Objectives: To illustrate the characteristic enhancement patterns and morphologic features of various solid renal cortical tumors smaller than 4 cm on biphasic multi-detector row computed tomography (MDCT). To demonstrate the schematic diagram for the characterization of small solid renal cortical masses on the basis of those properties.Background: Considering that different subtypes of renal tumors are associated with different clinical implications, it is important to differentiate these lesions preoperatively. The advent of MDCT using multiphasic contrast-enhanced studies has led to earlier diagnosis and sophisticated characterization of renal cortical masses. Between January 2004 and December 2006, 110 patients with small solid renal masses underwent biphasic MDCT (precontrast, corticomedullary, and early excretory phase). The pattern and degree of enhancement including homogeneity, segmental inversion, and lesion contour were reviewed.Imaging Findings: Most of the clear renal cell carcinomas commonly showed hetero-geneous enhancement with early washout pattern, whereas papillary, chromophobe subtypes, and lipid-poor angiomyolipomas showed homogeneous or fine reticular enhancement. Papillary lesions were usually hypovascular; chromophobe subtype and lipid-poor angiomyolipomas tended to enhance moderately. A majority of chro-mophobe subtypes showed homogeneous enhancement with fine reticulation and were round-shaped; lipid-poor angiomyolipomas showed prolonged homogeneous enhancement with lobulated or polygonal-contour. Most of the small renal oncocyto-mas showed segmental inversion of enhancement, which was a characteristic feature in the differentiation of renal oncocytoma from other small renal cortical tumors.Conclusion: Each subtype of small solid renal cortical tumors demonstrates characteristic enhancement patterns or morphologic features on biphasic MDCT, which are helpful in differentiating various renal cortical tumors.

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C-360 Clinical and radiological analysis of 209 cases of crossed fused ectopia and horseshoe kidney J. Petersen, C. Schenk, P. Rehder, T. Trieb, B. Glodny; Innsbruck/AT

Purpose: To describe the radiological appearance and diseases in kidney fusion anomalies (Fusion Kidneys [FK]: Crossed fused ectopia [CFE], and horseshoe kidney [HK]) in a very large patient group.Methods and Materials: 566 radiologic examinations of 209 subsequent patients have been systematically reviewed, including 244 CTs in 103 patients, and 233 sonographies.Results: The majority of FKs is detected incidentally, with the two exceptions of newborn, and 12-16 years old children with certain congenital syndromes. The prevalence of FKs is 1:410.5 (male/female ratio 1:2.03; CFE/HK 1:7.7). 23% of the patients (85.5% children, 14.5% adults) show concomitant urogenital (50%) or nonurogenital anomalies, in particular ureteropelvic junction obstruction and reflux, skeletal more than neural, cardiovascular and gastrointestinal anomalies. CFEs are located more caudally than HKs and are supplied by fewer vessels (p 0.0001 each). There is no difference in terms of concomitant anomalies or disease. Acquired urologic diseases are not more frequent than in unfused kidneys, except for trauma. Additional or accessory renal arteries are present in 96% (430 arteries in 103 kidneys). CT is superior to MRI or DSA in detecting these variants (p 0.0001 each). Their depiction is of paramount importance prior to aortic or urogenital surgery.Conclusion: Concomitant anomalies and diseases in FKs are much more infre-quent than previously reported, except for trauma. CT angiography is recommended prior to open or endovascular surgery of the aorta or the kidney.

C-361 Laparoscopic cryoablation (LC) of renal masses in patients affected by Von Hippel Lindau (VHL) renal cell carcinoma (RCC) syndrome and hereditary papillary (HP) RCC syndrome: Medium term outcome after 4-year magnetic resonance (MR) imaging follow-up G. Cardone, A. Cestari, L. Nava, P. Mangili, G. Guazzoni, G. Balconi; Milan/IT (cardoneg@tin.it)

Purpose: To determine the safety and efficacy of LC in the management of renal masses in patients affected by VHL-RCC syndrome and HP-RCC syndrome and to assess its medium term outcome after 4-year MR imaging follow-up.Methods and Materials: 5 pts affected by VHL-RCC syndrome and 6 pts affected by HP-RCC syndrome underwent LC of 29 tumors. Pts were followed up clinically, biochemically and by MR imaging 24h after surgery, and subsequently at 1, 3, 6, 12, 18, 24, 36 and 48 months. All MR examinations were performed using GRE T1w, TSE T2w and contrast-enhanced dynamic GRE FS-T1w sequences.Results: 24 hours after treatment, all cryolesions were more than 1 cm larger than the original masses; cryolesions decreased in size by an average of 38% at 1 month, 46% at 3 months, 64% at 6 months and 80% at 12 months following cryoablation. Early post-procedural MR ce-T1w images showed complete ischemia of all cryolesions. Follow-up (mean 16 months, range 6-48 months) revealed no evidence of local recurrence in all the patients. One patient affected by VHL-RCC syndrome demonstrated one metachronous nodule in the same kidney at 24 months. 4 pts affected by HP-RCC syndrome showed 6 metachronous nodules 12-36 months after treatment.Conclusion: Our medium term experience suggests that renal LC is a safe, well tolerated and minimally invasive therapy of renal masses in patients affected by VHL-RCC syndrome and HP-RCC syndrome, and MR is an effective imaging technique in the follow-up of renal lesions treated with LC.

C-362 Evaluation of the kidneys oxygenation in normal subjects and patients with renal transplant by BOLD MRI W. Xiao; Hangzhou/CN (xiaowb.111@163.com)

Purpose: Evaluated the oxygenation state of the kidneys in normal subjects and patients with renal transplants using BOLD MRI, and tried to find acute renal rejec-tion in early stage, instead of invasive transplant biopsies.Methods and Materials: BOLD MRI was performed in 15 healthy volunteers, 98 renal-transplant patients with normal renal function, and 18 with biopsy-proved acute rejection. MRI was performed on 1.5-T scanner system with 16 gradient-re-called-echoes at a gap of 1 mm and a 5-mm section thickness in the coronal plane. The R2*(1/sec) values for the cortex and medulla of the kidneys were recorded, respectively. Statistical analysis was performed using Student t tests. A threshold of R2* values was identified to discriminate transplanted kidneys with acute rejection and those with normal function.

Results: The R2* values of the medullary and cortex in normal function trans-plants (10.335 0.261/sec) and volunteers kidneys (11.722 0.491/sec) were quite similar, while the R2*values of the medulla in the acute rejection trans-plants (11.606 0.6231/sec) were lower than that in the normal function grafts (18.224 0.701/sec) (P=0.01). Furthermore, all the R2* values of the medulla with acute rejection were lower than 13/sec.Conclusion: Normally function transplants had a similar R2* values of the medul-lary and cortex as volunteers renal. Greatly decreased R2* value of the medulla in grafts ( 13/sec) were associated with a risk of acute rejection episodes.

C-363 Evaluation of cystic renal masses with thin-section multidetector CT by using the Bosniak classification system J. Wang, A. Zhu; Beijing/CN (wb62877701@yahoo.com)

Purpose: To evaluate the diagnosis value of thin-section multidetector row CT images in cystic renal masses by using the Bosniak classification system.Methods and Materials: Images of 140 renal cystic masses in 113 patients, who had undergone MDCT imaging examinations before surgery, were retrospectively analyzed by two radiologists blinded to pathology results in consensus. Each lesion was categorized by Bosniak classification system on 5 mm and 1 mm sec-tion images, respectively. The surgical-pathologic results were correlated with the MDCT findings. The Wilcoxon test was used to calculate the categorizing difference between 5 mm and 1 mm section CT images.Results: Among the 140 lesions, 17 were malignant (12%) and 123 were benign (88%). On 5 mm CT images, 111 lesions were classified as Bosniak type I; 9 as type II; 10 as type III; and 10 as type IV lesions, respectively. Histologically, 5 lesions were proved to be malignance for Bosniak type I, 2 for type II, 2 for type III, and 8 lesions for type IV in 5 mm CT images, respectively. While on 1 mm CT images, 105 lesions were categorized as type I, 11 as type II, 11 as type III, 13 as type IV lesions, respectively. Bosniak categories for cystic lesions was significant upgraded on the thinner section images (p 0.000).Conclusion: Thinner section CT images can be used to reveal some mild internal structure of complex cystic renal masses, and this will lead to significantly upgrade Bosniak categories for cystic lesions.

C-364 Effects of abdominal compression and prolongation of acquisition delay on imaging quality improvement of 64-slice spiral CT urography: Initial clinical experience H. Sun, H.D. Xue, W. Liu, X. Wang, Z.Y. Jin; Beijing/CN (sunhao_robert@126.com)

Purpose: To retrospectively evaluate the effects of abdominal compression and two delay phase acquisition on imaging quality improvement in 64-slice spiral CT urography.Methods and Materials: Medical records and informed consent of patients were obtained. In totally 52 patients (24 male, 28 female), two delay phase urographic imaging with a MSCT (Siemens Somatom Sensation 64) was performed. Scans began simultaneously with a contrast bolus injection of 100 ml (300 mgI/ml) and a saline bolus injection of 100 ml at a rate of 5 ml/s. Two delay phase urographic imaging were undergone at 400 and 500 seconds for each patient, respectively. Examinations were taken by using abdominal compression or no compression. Two reviewers evaluated urinary tract distention and opacification on transverse imag-ings, volume-rendered technique (VRT) images and maximum-intensity projection (MIP) images. Effects of abdominal compression and two delay phase acquisition were compared by using statistical mixed models with Chi-square test.Results: Abdominal compression improved distention (P 0.05) but does not improve opacification of the urinary tract. Delayed phase image acquisition of 500 seconds significantly increased distention of the intrarenal collecting system and proximal ureter (P 0.01). No statistically significant effects on the distal ureter were found with abdominal compression or two delay phase acquisiton. However, there were more visualized distal ureteral segments with the delayed phase image acquisition of 500 seconds, especially in renal function insufficient patients.Conclusion: Abdominal compression and longer imaging delays all improve imag-ing quality in 64-slice spiral CT urography, which is more obvious in renal function insufficient patients.

No Material Submitted to EPOS

No Material Submitted to EPOS

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C-365 Calculation of renal volume using respiratory-gated MRI: Intraobserver, interobserver, and interstudy reproducibility F. Di Terlizzi, S. Tiralongo, G. Di Leo, G.D.E. Papini, A. Morganti, F. Sardanelli, G.P. Cornalba; Milan/IT (f.sardanelli@grupposandonato.it)

Purpose: To test the reproducibility of renal volume calculation using MR.Methods and Materials: Ten patients without known renal disease (6 males, aged 35-72 years) underwent 1.5-T respiratory-gated 2D coronal true-FISP (TR/TE=4.30/2.15 ms; FA, 80 degrees; thickness, 3 mm, no gap; pixel size 1.2 mm square; time, 2’04”), repeated after one hour. Two readers (one resident in radiology, R1; one student in medicine, R2) segmented each kidney of both studies (one-week interval) with manual contouring method, subtracting the cysts; after another one-week interval, the segmentation of the first study was repeated. Renal volume was obtained multiplying the renal area on each slice by the slice thickness. Bland-Altman analysis was used.Results: Renal volume (mean SD) resulted 138 37 ml (right kidney, RK) and 143 40 ml (left kidney, LK) for R1, 147 40 ml and 153 45 mL for R2. On the total of 20 kidneys, intraobserver variability (bias 2SD) was 0.9 5.9 ml (RK) and 2.6 4.8 ml (LK) for R1, 1.2 5.6 ml (RK) and 2.9 11.3 ml (RK) for R2. Interobserver variability was -8.6 10.7 ml (RK) and -9.6 12.5 ml (LK). Interstudy variability was 0.3 12.8 ml (RK) and 0.6 11.3 ml (LK) for R1; 1.3 9.9 ml (RK) and 4.3 14.2 ml (LK) for R2. Segmentation time was 20-25 minutes for each session. Mean intraobserver and interstudy error bias was less than 1% for RK and ranged 0.4-1.9% for LK. Mean interobserver bias was 6.0% (RK) and 6.5% (LK).Conclusion: A highly reproducible measurement of renal volume can be obtained in two minutes of acquisition and less than 25 minutes of segmentation time.

C-366 Laparoscopic ultrasound-guided radiofrequency ablation of renal cell carcinoma: Feasibility and outcomes S. Yoon, J. Cho, J. Oh, K. Nam, M. Kang, J. Lee, K. Sung; Busan/KR (cerub@chol.com)

Purpose: To evaluate feasibility, midterm outcome, and complications with laparoscopic ultrasound-guided radiofrequency ablation (RFA) of renal cell carcinoma (RCC).Methods and Materials: Twenty-eight patients underwent RFA for 29 RCCs. Nine of 29 tumors were treated with RFA using laparoscopic ultrasound guidance (group A) and in the remaining 20 tumors, percutaneous CT or conventional ultrasound guidance (group B) was used. Follow-up CT after RFA was obtained at 1 day, 1 month, 3 months, and 6 months and then every 6 months with a mean follow-up of 28.5 months. We evaluated technical success, recurrence, and complications between the two groups.Results: RFA was technically successful in all tumors of group A (100%) and in 19/20 tumors of group B (95%). All 9 tumors were completely ablated after one session in group A, while 15/20 (75%) tumors in group B. Four of the remaining 5 tumors required second session and one tumor will require 4 ablation sessions in group B. In all group A, general anesthesia was performed, while in group B, RFA was undergone with intravenous conscious sedation. Mean operation time was 158.6 min in group A and 42.3 min in group B. Minor complications were present in 7 patients (25%); in group A, hematuria (n=1) and fever (n=1), and in group B, hematuria (n=3), fever (n=1), and mild hydronephrosis (n=1).Conclusion: Although general anesthesia and long operation time are required, laparoscopic ultrasound-guided RFA can be a feasible, effective, and safe treatment for selective patients with RCC.

C-367 Performance of low-dose CT for detection of urolithiasis: A meta-analysis T. Niemann, T. Kollmann, G. Bongartz; Basle/CH (niemannt@uhbs.ch)

Purpose: To perform a meta-analysis for evaluating the diagnostic performance of low-dose CT in the diagnosis of urolithiasis (7 studies, 1061 patients).Methods and Materials: Medical literature (from 1990 to 2007) was searched in PubMed, Medline and Cochrane Library databases for articles on studies that used low dose CT ( 3 mSv dose applied) as diagnostic tests for detection of urolithiasis. Prospective and retrospective studies were included if they separately reported the rate of true-positive, true-negative, false-positive, and false-negative diagnoses of urolithiasis from low dose CT compared with the positive and negative rates of normal dose CT or a combination of diagnostic tests. Two readers assessed the quality of studies.Results: Pooled sensitivity and specificity of low dose CT for diagnosis of urolithiasis were 0.966 (95% CI: 0.950, 0.978) and 0.949 (95% CI: 0.920, 0.970), respectively.Conclusion: This meta-analysis suggests that a low-dose CT protocol can be used as initial imaging modality in the workup of patients with suspected urolithiasis.

C-368 Transplanted kidney’s functional evaluation with contrast-enhanced power Doppler ultrasound and time/intensity curves P.V. Foti, R. Farina, F. Pennisi, C. Puglisi, M.V. Coronella, G.C. Ettorre; Catania/IT (pietrofoti@hotmail.com)

Purpose: To evaluate the diagnostic capabilities of contrast-enhanced power Dop-pler ultrasound (CEUS) with time/intensity curves in the study of renal graft function in order to identify pathognomonic patterns of both physiologic and pathologic (acute tubular necrosis and chronic rejection) conditions.Methods and Materials: 46 asymptomatic renal transplant patients (36 men and 20 women), 19 of whom had altered creatinine clearance levels, were studied by CEUS with time/intensity curves. US examinations were compared with renal biopsy available in all patients and considered as the gold standard. Ten asymptomatic patients with normal creatinine clearance levels were used as control group.Results: Time/intensity curves allowed representation of the kidney’s wash-in and wash-out phases after intravenous administration of contrast agent US. Time/intensity curves analysis enabled identification of three groups of patients: group A (27 patients) showing peak enhancement between 50 and 65 seconds from intravenous administration of contrast agent US; group B (16 patients) with peak enhancement between 135 and 235 seconds; group C (3 patients) with peak enhancement between 100 and 130 seconds. The control group showed a peak enhancement between 50 and 65 seconds. Biopsy demonstrated absence of disease in group A; it permitted a diagnosis of chronic rejection in group B and acute tubular necrosis in group C.Conclusion: CEUS is a non-invasive imaging technique that allows a functional evaluation of the transplanted kidney. The presence of pathognomonic patterns in patients with chronic rejection and acute tubular necrosis could allow the identifica-tion of pathologic conditions avoiding renal biopsy.

C-369 Unenhanced multidetector CT in the diagnosis of urinary tract calculi: Factors predicting a positive yield and the incidence of significant alternate diagnoses H.G. Delaney, S. O Keeffe, J.F.M. Meaney; Dublin/IE (hollydelaney@ireland.com)

Purpose: To determine which historical and biochemical parameters predict a posi-tive result when using unenhanced multidetector CT (CTU) in the detection of urinary tract calculi. To determine the incidence of clinically relevant ancillary findings.Methods and Materials: A retrospective review of 100 patients who underwent CTU in our institution was performed. The imaging findings were classified into positive and negative on the basis of the presence of urinary tract calculi. Other findings were subdivided into renal and extrarenal; incidental, significant, and as a possible alternative diagnosis. The referring details and relevant biochemical parameters were analysed and correlated with the presence of calculi.Results: Urinary tract calculi were confirmed in 42% while additional findings were seen in 43% of patients. A significant alternative diagnosis, feasibly accounting for the presenting symptoms, was demonstrated in 6%.The presence of haematuria had a negative predictive value of 95% for the presence of urinary tract calculi. There was no significant correlation with the presence of renal impairment or a history of urinary tract calculi. Lateralisation of symptoms had a negative predictive value of 92%, but otherwise historical factors were non significant.Conclusion: In our institution, 42% of patients referred acutely for CTU yield a positive result. Additional findings occurred in 43% but provided relevant alterna-tive diagnosis in only 6 patients. Establishing the presence of haematuria and lateralisation of symptoms before proceeding to CTU may increase the yield of this investigation and reduce unnecessary radiation exposure in the future.

C-370 Radiographic sizes versus surgical sizes of renal masses: Which is the true size of the tumor? B. Alicioglu, M. Kaplan, V. Yurut Caloglu, U. Usta, S. Levent; Edirne/TR (banualicioglu@trakya.edu.tr)

Purpose: The size of a renal neoplasm is important for staging, prognosis and selection of appropriate treatment. Our aim is to determine whether there is a discrepancy between the radiographic and pathologic sizes of renal tumors.Methods and Materials: In 35 renal tumors resected, the maximum size was measured on computed tomography imaging. The radiographic and pathologic sizes were compared by size range and tumoral radiological features.Results: The radiographic and pathologic sizes for all tumors were not significantly different (7.50 versus 6.25 cm, p=0.452). The average radiographic size was larger than pathological tumor size in the tumors smaller than 7 cm. The largest size differ-

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ences were seen in the tumors smaller than 4 cm in which the average radiographic size was 3.50 cm and the pathologic size was 3.0 cm.Conclusion: A reduction in the measurement of renal tumor size is commonly ob-served at surgical resection and explained by vasoconstriction during the temporal renal artery occlusion, surface hypothermia and blood loss during the surgery in tumors smaller than 7 cm. We suggest that if this reduction of size is secondary to surgery, the radiographic size of the renal tumors must be considered rather than pathologic size in staging and selecting the appropriate treatment.

C-372 Cortical renal volume measurements by using multi-detector row CT and its relationship with primary hypertension J. Vallejos, C.M. Capuñay, P. Carrascosa, J. Carrascosa; Vicente López/AR (investigacion@diagnosticomaipu.com.ar)

Purpose: To determine the relationship between cortical renal volume measure-ments by using multi-detector row CT and primary hypertension.Methods and Materials: 20 patients, 11 with hypertension, underwent abdominal angiography with a 16 row CT scanner. Renal length was measured by using multiplanar reformations. A contour-detection three-dimensional assessment for calculating cortical renal volume with the voxel-count method was developed. Two observers performed all measurements twice. The relationship between renal length and cortical volume was established. Differences in volume measurements between men and woman, between right and left kidney, and between normotensive and hypertensive patients were analyzed by using the Student t test. The ROC curve analysis was used to define the cut-off point of cortical renal volume between normotensive and hypertensive patients.Results: In all patients, the cortical renal volume mean value was 94.10 mL (range: 44.80-138.33), and the renal length mean value was 112.72 mm (range: 96.01-133.95). The correlation between renal length and cortical renal volume was weak, which means that renal length is a poor indicator of renal size. The cortical renal volume mean value in normotensive patients was 115.74 mL, whereas in patients with hypertension the mean cortical renal volume was 76.41 mL, with a difference of 39.33 mL (p 0.001, 95% CI: 23.07 a 55.58). A cut-off point of 102.10 mL (sensitivity: 100%, specificity: 88%) of cortical renal volume was found between normotensive and hypertensive patients.Conclusion: A significant reduction of cortical renal volume was observed in patients with primary hypertension.

C-373 Multi-detector computed tomography feasibility in calculating the cortical renal volume J. Vallejos, C.M. Capuñay, P. Carrascosa, J. Carrascosa; Vicente López/AR (investigacion@diagnosticomaipu.com.ar)

Purpose: To determine the repeatability of multi-detector computed tomography in quantifying the cortical renal volume.Methods and Materials: Twenty adults patients (mean age: 70 years) underwent abdominal angiography with a 16 row CT scanner (Brilliance 16; Philips Medical Systems). Renal length was measured by using multiplanar reformations. A contour-detection three-dimensional assessment for calculating cortical renal volume with the voxel-count method was developed. Two observers performed all measurements twice, with an interval of two weeks between the measurements. The relationship between renal length and cortical volumen was established. Differences in volume measurements between men and woman and between right and left kidneys were analyzed by using the Student t test. Intra and inter-observer variabilities of the measurements were determined by using the Bland and Altman method.Results: The cortical renal volume mean value was 94.10 mL (range: 44.80-138.33), and the renal length mean value was 112.72 mm (range: 96.01-133.95). The correlation between renal length and cortical renal volume was weak, which means that renal length is a poor indicator of renal size. No significant differences in cortical renal volume between the men and women or between the right and left kidneys were found. Intra and inter-observer variabilities of all measurements were lower than 1.5%, with limits of agreement for renal volumetry ranging from -1.47 to 3.05 mL.Conclusion: Cortical renal volume measurements with a 16 detector row computed tomography were repeatable.

C-374 Semi-automated region growing analysis of blood pool contrast enhanced MRI with open source software accurately predicts kidney volume as measured by a peri-operative fluid displacement technique in live renal donors G.C. Simpson, G.H. Roditi; Glasgow/UK (gcsimpson@gmail.com)

Purpose: Enhanced renal parenchymal volume is a surrogate of nephron number and decreases with declining renal function when kidney length may not. The vol-ume of perfused functional renal tissue is required to calculate split renal function. Contrast-enhanced MRI has been shown to be accurate for assessing porcine renal volume in an experimental model; however, there has been no validation in humans or with blood-pool contrast agents which have theoretical benefits for MRI renal perfusion analysis over conventional gadolinium agents.Methods and Materials: Ethics approval was obtained and 10 live renal donors undergoing pre-operative MRA to exclude underlying disease and evaluate reno-vascular anatomy were studied. Post contrast enhanced (10 ml Vasovist) coronally acquired breath-hold T1w THRIVE 3D datasets were analysed using OsiriX - an open source image processing software. Using the semi-automated region grow-ing tool, renal parenchymal volume was calculated. During transplant surgery, the volume of the transplant kidney was measured using a fluid displacement technique. Data was analysed using Pearson product-moment correlation coefficient.Results: Excellent agreement was found between MRI measurement of total renal enhanced parenchymal volume and peri-operatively assessed volume, with a Pearson product-moment correlation coefficient of 0.96.Conclusion: MRI measurements of enhanced renal volume with blood pool con-trast agent are accurate. This knowledge will aid in developing an accurate MRI assessment of differential renal function.

C-375 CT accuracy in characterising renal tumors: The Sheffield experience and implications for optimal treatment R.P. Singaroyan, F. Salim; Sheffield/UK (robinkings@aol.com)

Purpose: Approximately 10.5% of solid renal masses found on CT scans are benign. No serum markers for RCC exist and diagnosis rests solely on imaging. With recent advances in histopathology, accurate evaluation of biopsy specimens to determine malignancy is now possible. This avoids unnecessary nephrectomies and consequently has generated a debate on the management of indeterminate renal masses. Studies have shown masses measuring more than 5 cm are likely malignant.Methods and Materials: 81 cases of nephrectomy for renal parenchymal masses identified.CT appearances and histopathology were reviewed. CT imaging char-acteristics of benign masses were retrospectively analysed in comparison with their typical appearances. We have compared our results with ideal standard and results from previous studies.Results: Of the 81 cases of renal masses, 13.5% were found to be benign follow-ing nephrectomy. The average size of benign tumours were found to be 5.6 cm (range 2.5 to 12.5 cm)Conclusion: We found CT to be unreliable in distinguishing malignant from benign renal masses. The preoperative differentiation between a RCC and benign tumour on imaging can be difficult and our data suggest that a biopsy is necessary in selected patients to achieve the maximum accuracy in order to provide optimal treatment.

C-376 Renal masses: Imaging at contrast-enhanced ultrasound and correlation with computed tomography M. Valentino1, M. Bertolotto2, C. Serra1, R. Schiavina1, P. Pavlica1, L. Barozzi1; 1Bologna/IT, 2Trieste/IT (valentino@aosp.bo.it)

Purpose: Ultrasound (US) has become the primary imaging modality for inves-tigating the kidneys. Moreover, US still suffers some limitations in characterizing solid masses and complex cystic masses, and usually computed tomography (CT) must be performed in order to differentiate between benign and malignant tumors. Contrast-enhanced US (CE-US) is a novel technique reported to be able to assess tumor blood flow like CT. In this study, we reported the findings of the most common renal masses studied with US and CE-US in comparison with CT.Methods and Materials: In the last 2 years, 78 patients with solid or cystic renal masses were studied with US, CE-US and CT. Masses with diagnosis of malignant tumors were resected giving the final pathological diagnosis. Masses with diagnosis of benign tumors were followed for 1 year with US control, and the diagnosis was given by the absence of variation in imaging characteristics and/or sizes increase.

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Results: The final results were: 8 renal angiomyolipomas (AMLs), 23 renal cysts, 2 hypertrophied column of bertin, 4 oncocytomas, and 41 renal cell carcinomas. CE-US showed characteristics findings for every type of mass.Conclusion: CE-US was able to distinguish benign from malignant masses through their vascular characteristics. Demonstration of vascular abnormalities in solid renal mass, with rapid wash in and early wash out, was typical for malignant tumor.

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C-377 Imaging of the acute scrotum: Is there place for contrast-enhanced ultrasonography? H. Moschouris1, D. Kalikis1, E. Lampropoulou1, P. Goutzios2, M. Khalili1, D. Matsaidonis1; 1Piraeus/GR, 2Athens/GR (hipmosch@in.gr)

Learning Objectives: To illustrate the findings of Contrast-Enhanced UltraSo-nography (CEUS) in a variety of cases of acute scrotal pathology. To analyse the advantages and limitations of this method and suggest potential indications.Background: CEUS is not a standard part of scrotal imaging. Nevertheless, as a very efficient method of depicting micro- and macrocirculation, CEUS could con-tribute to the diagnosis of challenging cases of acute scrotal pathology.Imaging Findings: Representative cases of acute scrotum studied by ultrasound before and after the i.v. administration of a last generation ultrasound contrast agent (SonoVue, Bracco) are shown. These include: a) Testicular torsion (acute and chronic) which is rapidly and easily diagnosed with CEUS, as lack of enhance-ment of the affected testis. Moreover, CEUS can overcome the limitations of color doppler (due to artifacts or incomplete torsion). b) Epidydimitis, orchitis and their complications. Emphasis is placed on the ability of CEUS to detect scrotal, testicular and epidydimal abscesses (with typical rim enhancement) and post-inflammatory ischemia of the testis. c) Scrotal trauma. Severely traumatized testes show weak, in-homogeneous or patchy enhancement, while minor contusions cause no significant enhancement defects. Hematomas present as focal lesions lacking enhancement. The findings of CEUS are correlated with those of grey-scale and color doppler ultrasonography. Reference to the limitations of scrotal CEUS and some practical and technical issues are also included in the presentation.Conclusion: In selected cases of acute scrotum, CEUS may be proved a practical and effective complement to grey-scale and color Doppler ultrasonography.

C-378 Benign intratesticular cystic lesions: US features C. Pozuelo, O. Pozuelo, Y. Roca, L. Mones, M. Romero, X. Mallol; Barcelona/ES (crispozuelo@hotmail.com)

Learning Objectives: To presents the spectrum of benign intratesticular cystic lesions that can be easily characterized by US.Background: Ultrasonography (US) is the modality of choice for characterization of palpable testicular lesions. Extratesticular lesions are more common than intra-testicular ones, and more than 95% of intratesticular lesions are malignant, which are usually treated by means of radical ochiectomy. Nonneoplastic cystic lesions represent a subset of intratesticular lesions of which the majority are benign.Imaging Findings: A total of 1389 patients were reviewed retrospectively in our hospitals between January-02 and July-07 using a high-resolution scanner with a high-frequency transducer. Benign lesions include intratesticular simple cysts, tubular ectasia, epidermoid cyst, tunica albuginea cyst, intratesticular varicocele, abscess, and hemorrhage (infarction). US features of cystic malignant neoplasms that help in differentiating them from benign cystic lesions are also presented.Conclusion: Benign intratesticular lesions are rare, but recognition is important to avoid unnecessary surgical intervention.

C-379 Peri-prostatic neurovascular bundle: Pre and post-surgical MRI assessmentV. Panebianco, A. Sciarra, M. Osimani, D. Lisi, A. Consoli, R. Passariello; Rome/IT (valeria.panebianco@uniroma1.it)

Learning Objectives: To assess morphological features about peri-prostatic neurovascular bundle region, to staging pre-surgery prostate cancer infiltration and to evaluate anatomical integrity after nerve-sparing radical retro-pubic pros-tatectomy.Background: Preservation of the neurovascular bundle (NVB) and potency without compromising tumor control are current objectives of radical retropubic prostatec-tomy as treatment for prostate cancer, but pre-surgical determination of whether cancer has invaded the NVB can be difficult. MRI allows the urologists to have a correct pre-surgical anatomic mapping of the NVB. In this exhibit we introduce the use of a sequence that we optimized to assess morphological features of peri-prostatic neurovascular bundle region.Procedure Details: We carried out our MRI sequence 3D T2 C1 ISO on axial plane, centered on prostatic fossa and covering entire NVB course (TR: 5.64, TE: 2.46, TA: 4.30 slice thickness. 0.70, FOV 180 x 100), before and after nerve-sparing

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radical retro-pubic prostatectomy. The images were obtained using a 1.5 T magnet (Magnetom Avanto Siemens, Erlangen, Germany).Conclusion: Images obtained by the use of this sequence provide an entire ana-tomic and morphologic view of the NVB and the presence of cancer infiltration. Furthermore, surgical lesions of the NVB could be detected in a post-operative MRI study.

C-380 Variable imaging findings of prostate cancer: Focus on MR and PET/CT imaging J. Jang, J. Byun, M. Kim, Y. Lee, S. Oh, S. Rha, I. Yoo; Seoul/KR (znee99@gmail.com)

Learning Objectives: To illustrate the variable imaging findings of prostate cancers with focus on MR and PET/CT images.Background: Multiple imaging modalities play critical roles in the staging of prostate cancer. But there are controversies about the exact indications, sensitivities and specificities of imaging modalities including ultrasound (US), computed tomogra-phy (CT), magnetic resonance (MR) imaging, and combined positron emission tomography and computed tomography (PET/CT). In this exhibition, we reviewed the variable imaging findings of prostate cancer in imaging modalities with focus on MR and PET/CT imaging.Imaging Findings: US and CT show nonspecific imaging features in patients with prostate cancers. So US is used mainly for measuring the volume of the prostate gland and for US-guided systematic biopsy, and CT does the role of nodal staging. On MR, prostate cancers show low signal intensity on T2-weighted image (T2WI), in contrast to the high signal intensity of the peripheral zone. It is difficult to detect prostate cancer in the transitional zone on MR because of background low signal intensity of transitional zone on T2WI. MR spectroscopy, dynamic contrast enhance-ment, diffusion weighted image and the usage of new contrast media are potential MR methods for more precise detection and localization of prostate cancers, with several practical reports. PET/CT overcomes limitations of PET, so new clinical applications are expected.Conclusion: Prostate cancers show variable imaging findings according to the multiple imaging modalities. MR and PEC/CT have important clinical role in patients with prostate cancers. So radiologists should be familiar with the variable imaging findings of prostate cancers.

C-381 Sonographic appearance of tuberculous epididymitis and epididymo-orchitis N. Goyal1, V. Rachapalli2, S. Ramamurthy2, N. Jain2, S. Rashid2, D.L. Cochlin2, R. Clements1; 1Newport/UK, 2Cardiff/UK (sidi.rashid@yahoo.co.uk)

Learning Objectives: 1. To illustrate the sonographic findings of tuberculous epididymitis and epididymo-orchitis. 2. To increase the awareness of the common differential diagnosis with similar findings.Background: Prevalence of extrapulmonary tuberculosis is increasing in Europe because of the human immunodeficiency virus epidemic and human migra-tory patterns. The most common manifestation of extrapulmonary tuberculosis is genitourinary tuberculosis. Clinically, it may be difficult to differentiate tuberculous epididymo-orchitis from other lesions such as tumour or infarction. It is important that sonographers correctly appreciate the condition because timely commence-ment of chemotherapy can prevent orchidectomy. The ultrasound appearances and common differential diagnosis are discussed.Imaging Findings: Grey-scale ultrasound imaging and Doppler imaging findings have been illustrated. Tuberculous epididymitis is homogeneously or heteroge-neously hypoechoic on ultrasound and there is diffuse or nodular enlargement of the epididymis. An enlarged epididymal tail has been described as a differentiating feature between tuberculous and non- tuberculous epididymitis. Tuberculous orchitis is similarly hypoechoic and may be focal or diffuse. The presence of multiple small hypoechoic nodules in an enlarged testis gives a miliary pattern and is characteristic of tuberculous orchitis. Other ultrasound features include scrotal skin thickening, scrotal abscesses and scrotal sinus tract.Conclusion: High-resolution ultrasound is currently the best technique for imaging the scrotum and its contents. Awareness of sonographic features of tuberculous epididy-mitis and epididymo-orchitis is crucial for a competent interpretation of findings.

C-382 Prostate cancer (PC) evaluation: Usefulness of keyhole subtracted dynamic contrast-enhanced (CE) MR sequence G. Cardone, C. Iabichino, L. Nava, M. Freschi, P. Mangili, G. Guazzoni, G. Balconi; Milan/IT (cardoneg@tin.it)

Purpose: The aim of this study is the evaluation of the usefulness of digital sub-tracted-keyhole-GRE sequence in the study of prostate cancer using ce-dynamic MR imaging.Methods and Materials: 29 patients with localized prostate cancer underwent MR evaluation before surgery. All MR examinations were performed with a 1.5 T MR system and an endorectal coil, using conventional multiplanar TSE T2w sequences, followed by dynamic ce-keyhole-GRE T1w sequence. Subsequently, ce dynamic MR images subtraction was obtained. All data sets (T2w, ce GRE T1w and subtracted ce GRE T1w images) were qualitatively and quantitatively (time/intensity curves) evaluated.Results: On conventional T2w MR images, neoplastic lesions were evident in 52% (15/29) of the cases. On conventional dynamic ce-GRE T1w MR images, neoplastic lesions were evident in 83% (24/29) of the cases. On subtracted dynamic ce-keyhole-GRE T1w MR images, neoplastic lesions were evident in 93% (27/29) of the cases. The keyhole technique allowed acquisition time reduction, with improvement in time resolution. Sub-tracted images showed higher contrast resolution in the focal early enhancement areas evaluation compared to the conventional dynamic images. Prostatic lesions were evident on subtracted ce T1w images only in 3 cases. Digital subtraction technique minimized the high signal intensity of perirectal and periprostatic fat and the high signal intensity of the prostatic parenchima related to previous byoptic procedures.Conclusion: In our study, subtracted dynamic ce-keyhole-GRE T1w MR imaging allowed a better evaluation of the prostatic neoplastic lesions compared to the T2w and conventional dynamic MR sequences.

C-383 Prostate adenocarcinoma: Evaluation of gadolinium dynamic T1-weighted MR imaging and ADC values K. Hayasaka1, T. Nihashi2, K. Nojiri1, K. Okamura1; 1Ohbu/JP, 2Nagoya/JP (ckv37824@mopera.ne.jp)

Purpose: To determine whether the combined use of dynamic gadolinium-enhanced (DCE) and diffusion-weighted (Dw) MRI facilitates a more effective diagnosis for prostate carcinoma than each technique alone.Methods and Materials: Eighty-one patients (45 tumor-free patients and 52 prostate carcinomas of 36 patients) with increased PSA ( 4.0 ng/mL) underwent MRI on a 1.5 T scanner prior to TRUS-guided biopsies. The average value of the contrast-en-hancement ratio in 60 sec (DCE-R60) and 120 sec (DCE-R120), ADC (calculated from b-values of 0 and 1000), and ADC/DCE-R60 were determined. The correlation between those MRI parameters and the Gleason score (5-7 and 8-10) was evaluated. Correlation with histology was based on biopsy in all cases. Student's t-test was used for statistical analysis. Receiver operating characteristic (ROC) curves were estimated with the ROCKIT 1.1B beta version program (C Metz, Chicago, IL).Results: The average values of all MRI parameters except DCE-R120 showed significant differences between tumor-free and prostate carcinoma cases. In Gleason score, 42 lesions had score of 5-7, and 10 had score of 8-10. In the cor-relation between all MRI parameters and the Gleason score, significant difference was noted only between ADCs (P=0.003). The Az values for each ADC, DCE-R60, DCE-R120, ADC/DCE-R60, and ADC with DCE-R60 were 0.992, 0.732, 0.634, 0.875, and 0.996, respectively.Conclusion: All except one DCE-R- and ADC-MRI parameter showed significant differ-ences between tumor-free and prostate carcinoma cases. The combined use of DCE and Dw MRI is considered to enhance the detection accuracy of prostate carcinoma.

C-384 The usefulness of the ADC value in hormone refractory prostate cancers on diffusion-weighted MR images for predicting the effect of chemotherapy T. Yoshizako, M. Sumura, A. Wada, T. Hayashi, T. Katube, K. Uchida, S. Hara, N. Uchida, H. Kitagaki, M. Ikawa; Izumo Shimane/JP (yosizako@med.shimane-u.ac.jp)

Purpose: The purpose is to investigate whether the apparent diffusion coefficients (ADC) values of hormone refractory prostate cancer (HRPC) can predict the response to chemotherapy.Methods and Materials: Our study population included 21 patients with pathologi-cally proven HRPC who underwent 2 cycle chemotherapy (DEC therapy: Docetaxel, Carboplatin, Estramustine) and MRI for the evaluation of cancer before and after che-motherapy. 10 patients were pathologically effective for chemotherapy and 11 patients

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were pathologically non-effective for chemotherapy. All studies were performed with a 1.5 T superconducting system with TORSO coil. DWI data were acquired using a single-shot EPI sequence. ADC maps were reconstructed by calculating ADC values (b-value was 0 and 1000 sec/mm2). Finally, the ADC value of cancer was compared between effective and non-effective groups before and after chemotherapy. The cancer area was suspected by MRI and biopsy before hormone therapy.Results: In the effective group, the averaged ADC value (10-3 mm2/s) of cancers before chemotherapy was 1.392+0.192 and after chemotherapy was 1.261+0.043. In the non-effective group, that of cancers before chemotherapy was 1.043+0.032 and after chemotherapy was 0.805+0.046. The averaged ADC value of cancers before chemotherapy was significantly different between the effective group and the non-effective group before chemotherapy (P 0.05).Conclusion: The measurement of the ADC value in HRPC may be useful in predicting the effect of chemotherapy. The averaged ADC value of cancers before chemotherapy with effect group was significantly higher when compared with the non-effective group.

C-386 Local cancer recurrence after radical prostatectomy: Endorectal coil MR imaging at 1.5 T better accuracy level in selected patients V. Panebianco, M. Osimani, M. Di Martino, D. Lisi, A. Consoli, R. Passariello; Rome/IT (valeria.panebianco@uniroma1.it)

Purpose: To compare accuracy level of 1H-spectroscopic MR imaging (1H-MRSI) and dynamic contrast enhanced MR imaging (DCEMRI) at 1.5 T field in the diag-nosis of prostate cancer recurrence after retro-pubic radical prostatectomy (RRP) in patients with small loco-regional foci.Methods and Materials: Twenty five patients with trans-rectal US (TRUS)-biopsy proved local prostate cancer recurrence (mean dimension 5 2 mm) after RRP and mean PSA values of 0.6 ng/ml underwent MR examination on 1.5 T scanner (Avanto, Siemens, Erlangen, Germany), equipped with surface phased-array and endo-rectal coil. 3D chemical shift imaging (CSI) was acquired for 1H-MRSI (1024 voxels for patient and nominal spectral resolution 0.3 cm3) and for DCEMRI contrast agent concentration-time curves were assessed. All images were reviewed independently by two readers who were blinded to clinical information.Results: 1H-MRSI analysis showed a sensitivity of 66% and specificity of 78%; DCEMR a sensitivity of 77% and specificity of 98%. The lower performance of 1H-MRSI may reflect that voxel size for spectroscopic data is larger than for DCEMR data, and patients would be predicted to have smaller volume disease.Conclusion: DCEMRI was more accurate than 1H-MRSI in the correct depiction of small loco-regional recurrence prostate cancer and may avail the diagnosis in those patients in whom a prostatic bed TRUS biopsy is difficult to perform because of the small volume of the mass. Partial volume effects may be predicted to be more problematic with spectroscopy in the setting of small volume disease.

C-387 Prostate cancer: Pre-treatment evaluation with MRI and three-dimensional 1H-magnetic resonance spectroscopy S. Giusti, M. Lazzereschi, F. Francesca, A. Tognetti, C. Bartolozzi; Pisa/IT (bartolozzi@med.unipi.it)

Purpose: To compare 3D MRI and MRS in pts with biopsy proven prostate carci-noma; to find a cut-off value of (Cho+Cr)/Cit ratio; and to find a correlation between (Cho+Cr)/Cit ratio and Gleason score.Methods and Materials: 26 pts underwent endorectal MRI and MRS for the evaluation of tumor location, local extent and aggressiveness of prostate cancer followed by radical prostatectomy. Our protocol consisted of tra, cor and sag T2 and tra T1wi TSE sequences. MRS data were acquired by a 3D CSI. Biopsy, MRI, MRS and MRI+MRS readings were correlated with pathology results.Results: Biopsy showed: sens. 86%, spec. 67%, accuracy 83%, NPP 50%, PPV 92%; MRI showed: sens. 84%, spec. 89%, accuracy 85%, NPP 53%, PPV 97%; MRS showed: sens. 84%, spec. 78%, accuracy 83%, NPP 50%, PPV 95%; MRI+MRS showed: sens. 91%, spec. 78%, accuracy 88%, NPV 64%, PPV 95%. Cohen’s test demonstrated that biopsy had a lower degree of agreement with histology than MRI+MRS combined. We classified the spectra as normal if ratio was 2 SD and pathologic if ratio was 2-3SD or 3 SD from the normal. Our cut-off was 0.47 (sens 89.2%, spec 91%). We distinguished five degree of Gleason score and obtained a significative correlation between ratio and Gleason score.Conclusion: MRI+MRS demonstrated a better sensitivity and accuracy in tumor localization than did MRI alone. The best cut-off value to discriminate between cancer and normal prostatic tissue was 0.47. High-grade cancers revealed highly elevated cho resonances, whereas lower grade tumors showed slightly elevated choline levels only.

C-388 Use of regional anesthesia during TRUS biopsy of the prostate results in decrease of patient pain and discomfort, without increasing complication rate D.D. Cokkinos, I. Theotokas, K. Pahos, A. Plagou, E. Skoulikaris, P.S. Zoumpoulis; Athens/GR (echo@hol.gr)

Purpose: To analyze the impact of routine local anesthesia administration during TRUS biopsy of the prostate on patient tolerance and pain.Methods and Materials: We studied retrospectively data from 5000 patients who underwent TRUS and biopsy of the prostate during the years 1993-1998 (group A) without anesthesia. Pain during the procedure was evaluated by the patients on a visual analogue scale (0-10). A median degree of pain was calculated and compared to that of 6000 patients who also underwent TRUS biopsy during the years 1998-2007 (group B) after local administration of anesthesia (5 ml xylocaine/adrenaline 2% injected via the biopsy needle between prostate base and seminal vesicles-2.5 ml on each side). We also assessed the frequency of complications (rectal bleeding, hematuria, infection and sepsis, urine retention) in the two groups. A Student paired t test was performed for mean pain degree and complication rate between the two groups. A p value less than 0.05 was considered as statistically significant.Results: Pain was significantly lower in group B in comparison with group A (me-dian patient pain: 8.2 in group A, 5.3 in group B-p=0.032). There was no increase in complication rate due to anesthesia administration (complication rate: 2.2% in group A, 1.9% in group B-p=0.72).Conclusion: Local anesthesia administration during TRUS biopsy of the prostate reduces patient pain and discomfort, making the examination better tolerated. It is not related with an increase in complication rate. Therefore, we use regional anesthesia as a routine in all our patients.

C-389 Endorectal magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) in patients with elevated prostate specific antigen (PSA) level and prior negative biopsy S. Cirillo, M. Petracchini, T.M. Gallo, P. Dellamonica, A. Manca, V. Tartaglia, D. Regge; Candiolo/IT (stefano.cirillo@ircc.it)

Purpose: To evaluate the accuracy of MRI and MRS in detecting peripheral zone tumour in patients with PSA values 4 ng/ml and previous negative transrectal ultrasound (TRUS) biopsy round.Methods and Materials: Fifty-four consecutive men underwent a combined MRI-MRS examination with endorectal coil. MRI included transverse, coronal and sagittal T2-weighted and transverse T1-weighted fast spin-echo sequences. MRS data were acquired using a double spin-echo PRESS sequence. A 10 site scheme was adopted to evaluate the prostate peripheral zone. A peripheral prostatic site was classified as suspicious if low intensity signal was present on T2 weighted images and/or if choline+creatine/citrate ratio was 0.86. Following MRI-MRS all patients were submitted to a standard 10-core biopsy scheme to which from 1 to 3 supplementary samples were added from suspicious MRI and/or MRS sites. In per-patient analysis findings were considered true positive if biopsy positive patients were classified as suspicious, irrespective of lesion site indication.Results: Prostate cancer was detected in 17 of 54 patients (31.5%); on a per-patient basis sensitivity, specificity, PPV, NPV and accuracy were respectively 100%, 64.9%, 56.7%, 100% and 75.9% for MRI; 82.2%, 70.3%, 57.7%, 92.9% and 75.9% for MRS and 100%, 51.4%, 48.6%, 100% and 66.7% for combined MRI-MRS.Conclusion: Our results show that MRI alone might be able to select negative patients in whom to avoid further biopsies. The combination of MRI and MRS might be able to drive biopsies in suspicious sites and increase cancer detection rate. Other studies are needed to confirm these data.

C-390 Changes of testicular blood flow after vasectomy evaluated by ultrasound resistive index measurement R. Faschingbauer, F. Aigner, E. Pallwein, G. Bartsch, F. Frauscher, L. Pallwein; Innsbruck/AT (ralph.faschingbauer@i-med.ac.at)

Purpose: The goal of this study was to evaluate changes in testicular blood flow in patients after vasectomy by use of color Doppler ultrasound resistive index (RI) measurements.Methods and Materials: Included were fifty healthy men scheduled for vasectomy. All patients underwent RI measurements pre-and postoperatively (3 and 6 months). The RI of the testicular arteries was measured at two locations using color Dop-pler ultrasound with a linear array 15-MHz transducer (Acuson, Sequoia): at the level of spermatic cord (level 1) and intratesticular close to the rete testis (level 2). Additionally, the volume of the testicles was determined.

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Results: The mean volume of the testes was 17.5 5.7 mL before and 19.7 7.1 mL after vasectomy. Measures for left and right testes were similar (P 0.10). Three months after vasectomy, the RI at level 2 showed a significant (P 0.05) increase from 0.51 0.09 to 0.59 0.08. The RI returned to basic values at the 6 months control (mean RI: 0.52 0.07). In comparison we found no significant change of RI at level 1.Conclusion: The RI seems to be a reliable indicator for testicular blood flow. The significant increase after vasectomy may indicate a slightly decreased perfusion of the testicles due to a transitory lymph edema. Further investigation will show the utility of RI measurements in estimation of testicular function.

C-391 MRI and 1H MRS of benign disease of prostatic peripheral zone: Comparison with prostate adenocarcinoma L. Zhou; Shanghai/CN (zhoulp-2003@163.com)

Purpose: The purpose of this study was to probe the value of combining MR imaging and three dimensional H-1`MR spectroscopic imaging (3D 1H MRSI) in diagnosing benign disease of prostatic peripheral zone (PZ).Methods and Materials: 16 cases of benign disease of prostatic peripheral zone proved pathologically underwent MR imaging and 3D 1H MRSI were reviewed and compared with 16 cases of prostate cancer which were proved by pathology of systemic biopsy.Results: Most of benign lesion was nodular and well-defined lesion (69%). Pros-tate adenocarcinoma presented mainly as patch-like lesion with nodular feeling and ill-defined (56%). The average volume (1.96 cm3 1.92 cm3) of benign lesion were significantly less than that (4.34 cm3 2.74 cm3) of prostate adenocarcinoma (t=2.68, P=0.013). The signal intensity of most of benign lesion and most of pros-tate adenocarcinoma were less than that of normal PZ and were closed to that of inner obturatoria muscle on T2 weighted imaging and presented as iso-intensity comparison with that of normal PZ on T1 weighted imaging. There were no statistic difference between two group ( 2=0.731, P=0.392). The mean ratio (0.68 0.17) of choline+creatine/citrate (Cho+Cre/Cit) of benign lesion were significantly less than that (2.30 0.79) of prostate adenocarcinoma (t=7.54, P=0.000).Conclusion: There were statistical differences of the shape, the volume on MR imaging and metabolic levels measured by 3D 1H MRSI between benign lesion of prostatic PZ and prostate adenocarcinoma. Combining the results of MR im-aging and 3D 1H MRSI will play an important role in diagnosing benign lesion of prostatic PZ.

Genitourinary

Miscellaneous

C-392 Amyloidosis: Review of imaging findings P. Calvo, M. Céspedes, S. Aso, E. Fandiño, M.I. García-Hidalgo, Y. Herrero; Toledo/ES (puricalvo@hotmail.com)

Learning Objectives: The aim of this teaching exhibit is to familiarize the radiolo-gist with amyloidosis. To describe a spectrum of imaging features of primary and secundary amyloidosis with pathologic correlation.Background: Amyloidosis is a collection of disease entities that are characterized by the abnormal extracellular deposition of insoluble amyloid protein. The incidence of amyloidosis has been increasing, maybe, due to the longer life expectancy of patients with chronic diseases. The majority of cases is secondary type and is as-sociated with chronic inflamatory diseases. The imaging findings are non specific and diverse reason why the radiologist must be familiar with them as well as the patient´s clinical history and associated diseases.Imaging Findings: We illustrate the imaging findings of 24 patients, with biopsy-proven or post-mortem confirmed cases, diagnosis of amyloidosis over last 10 years, from database of our institution. We find several radiological appearances: focal form, tumorlike lesion or an infiltrative process and it can involve one organ or in conjunction with other organs. In primary amyloidosis, the most common sites involvements are kidneys and skin. The secondary amyloidosis is most frequent presentation and kidney is the organ most common affected. Other regions’ involvements are gastrointestinal tract, heart, musculoskeletal system and retroperitoneo.Conclusion: The imaging findings in amyloidosis are extremely diverse and non specific but it must be considered in the differential diagnosis mainly in patients with chronic inflamatory disease. Biopsy is the best method to do an accurate diagnosis.

C-393 3 Tesla MRI of the pelvis: Challenges and solutions for clinical applications A. Coupteau, F. Bonnet, C. Hoeffel, C. Portefaix, L. Job, C. Marcus; Reims/FR (alexandra.coupteau@free.fr)

Learning Objectives: 1. To outline some technical challenges and solutions for 3 T MRI of the pelvis. 2. To illustrate the feasibility of routine 3 T MRI of the pelvis. 3. To present promising areas in which 3 T MRI may have a clinical impactBackground: Potential advantages of MRI at 3 Tesla include higher signal-to-noise ratios, better image contrast, particularly in gadolinium-enhanced studies, yielding higher spatial resolution images and faster imaging. However, achieving superior imaging quality at 3 T is challenging. We review many of the problems encountered in pelvic evaluation such as increased susceptibility, B1 field inhomogeneity and increased specific absorption rate. We consider solutions that are being pursued. We discuss and illustrate high field strength MR examinations of benign and malignant genito-urinary diseases as well as rectal diseases.Imaging Findings: MR images were obtained using a 3 T MR unit (Achieva, Philips) with a phased-array cardiac coil. Parallel imaging was used to provide improved resolution. High-resolution images provide good evaluation of gynecologic but also prostate, bladder and rectal cancers. Precise assessment of benign diseases (myomas, adenomyosis, endometriosis, etc.) is also possible. Our experience with diffusion imaging in pelvic diseases is presented.Conclusion: MR imaging of the pelvis appears feasible at high field strength in routine practice and has a potential for the development of functional studies. However, familiarity with the key technical challenges is necessary in order to obtain good image quality.

C-394 Cross sectional imaging appearances of extra-adrenal paragangliomas A. Sahdev, N. Stephens, P. Narayanan, A.G. Rockall, R.H. Reznek; London/UK (anju.sahdev@bartsandthelondon.nhs.uk)

Learning Objectives: To recognise the unusual sites of extra-adrenal phaeochro-mocytomas and their imaging appearances.Background: Extra-adrenal paragangliomas can occur within the sympathetic gan-glia from the skull base to coccyx and within viscera containing sympathetic nerves such as the heart, bladder and prostate. 60% of extra-adrenal paragangliomas are malignant and surgical resection is optimal management for these tumours.Imaging Findings: CT and MR imaging of 65 extra-adrenal tumours in 30 patients were analysed. Site, size, CT and MR signal characteristics and enhancement

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after intravenous contrast media were recorded. The 123-I-MIBG results, plasma catecholamines and the relation of tumour to adjacent structures were correlated. The majority of extra-adrenal tumours were carotid body tumours, characteristically splaying the common carotid artery bifurcation. 79% were 2 cm and larger with intra-lesional serpiginous vascular flow voids resulting in the ‘salt and pepper’ appearance on MR. Retroperitoneal tumours were the next most common site, 92% distributed around the inferior vena cava and aorta. 2 bladder, 1 urachal, 1 pelvic, 1 cardiac, 2 middle mediastinal and 2 spinal extra-adrenal paragangliomas were seen as ir-regular masses. Following intravenous contrast enhancement, avid enhancement was demonstrated by all paragangliomas. All 65 masses were intermediate signal intensity on T1- weighted and high signal intensity on T2- weighted scans.Conclusion: The diagnosis of extra-adrenal paragangliomas can present a diag-nostic dilemma. Many are MIBG negative and an appreciation of possible sites together with range of appearances can help in a speedy diagnosis.

C-395 CT findings of incontinent urinary diversion (Bricker procedure) following radical cistectomy: A comprehensive pictorial review of postsurgical anatomy, common and uncommon complications V. Catala, M. Solà, C. Quintian, J. Alberola, J. Palou, P. De la Torre; Barcelona/ES (violetacatala@yahoo.com.ar)

Learning Objectives: 1-To review the surgical technique of Bricker procedure (BP) following radical cistectomy. 2-To familiarize the reader with optimal multidetector CT (MDCT) technique. 3-To review the normal anatomy and common/uncommon complications after this procedure.Background: BP following radical cistectomy is an extended and accepted treat-ment for patients with muscle invasive bladder cancer. Because it is a complex surgical procedure, early and late postsurgical complications are frequent. A correct diagnosis of those complications is mandatory in order to achieve an adequate management of these patients.Imaging Findings: 313 scans were performed in patients after BP to rule out surgical complications. We describe normal MDCT postsurgical anatomy and com-mon and uncommon complications (all complications were confirmed by surgical or interventional procedure): collections (abscess, urinoma, linphocele); fistulas; intestinal occlusion and subocclusion; peristomal herniation (with and without peristomal herniation complications); stones; ureteral stenosis; anastomosis leak; and tumor recurrence. We use dynamic diagrams (flash program) in order to show more clearly the main complications.Conclusion: 1-CT technique is an accurate method to detect early and late complications of BP following radical cistectomy. Multiplanar reconstruction and 3D-rendered images using MDCT are useful tools to make a correct diagnosis in these patients, giving the surgeon essential information for an adequate manage-ment. 2-Knowledge of normal postsurgical appearance and optimal CT technique are essential to diagnose complications and to avoid misdiagnosis.

C-396 Pictorial review of urothelial tumours with pathological correlation I.P. Gunatunga1, S. Singh1, R. Gadahadh2, C. Davies1, G. Davies1; 1Cardiff/UK, 2Swansea/UK (ishangune@gmail.com)

Learning Objectives: 1. To demonstrate imaging features of histologically con-firmed urothelial tumours as seen on different imaging modalities. 2. To highlight the benefits of CT and CT urography in assessment of urothelial tumours. 3. To demon-strate the usefulness of coronal and sagital reformats with 64 MDCT in the diagnosis and staging of upper tract urothelial tumours. 4. To review the differential diagnoses and their salient features which differentiate them from urothelial tumours.Background: The entire urinary tract is lined by transitional cell epithelium and has potential to undergo malignant transformation. Regardless of location, a characteristic of urothelial tumours is their likelihood to develop synchronous le-sions. There can be great difficulty in diagnosing these tumours with conventional radiological methods.Imaging Findings: This exhibit is to demonstrate imaging features of urothelial tumours with intravenous urography, ultrasound, CT and MRI and highlight the benefits of contrast CT Urography with particular reference to coronal and sagital reformat with 64 slice MDCT. We will review the differential diagnoses and their salient features which differentiate them from urothelial tumours.Conclusion: CT urography with coronal and saggital reformats greatly increase the confidence in diagnosing and staging upper tract urothelial tumours.

C-397 The MR-urethrography in the evaluation of urethral diseases C. Parola, G. Regine, C. Pace, M. Gaffi, L. Adami; Rome/IT (cparola@scamilloforlanini.rm.it)

Learning Objectives: To define and discuss the diagnostic performance of MR in the evaluation of the male urethral stenosis compared to traditional urethro-cistography.Background: The urethral stenosis lesion is one of the most important genitalia diseases in males. Can lead young especially and may follow a trauma or flogosis, rarely is neoplastic. The aim of this exhibit is to describe the procedure details to perform a urethro-MR.Procedure Details: 9 patients, age 21-46, between January and June 2007 were evaluated. The technique was: supine position, administration of 30-50 cc of saline solution by a catheter located in navicolar fossa. Using a cardiac coil was performed the examination using the following sequences with a 1.5 T magnet: Sagittal fast spin echo T2 e T1 weight, sagittal and coronal T2 with fat saturation (single slice), 3D FIESTA (thin slices) and permintional cine-FIESTA (single slice). After MR examination the patients were underwent to traditional urethro-cistogra-phy. The diagnostic results were compared and the stenosis number and length identified by MR urethrography were confirmed but the MR evaluated also the near tissue flogosis.Conclusion: The MR urethrography showed an optimal diagnostic accuracy and good tolerance respect to the reference technique. The advantage is that it does not use radiation and contrast media.

C-398 Fetal MRI: Incremental value in fetal imaging and impact on decision making J. Singh, K. Godbole, V.M. Bhide; Pune/IN (joshitasingh@hotmail.com)

Learning Objectives: To illustrate the utility and incremental value of fetal magnetic resonance imaging (MRI) in decision making in patients with ultrasound (USG) detected anomalies and in patients with high recurrence risk for multiple structural anomaly syndromes without a specific genetic diagnosis.Background: Fetal imaging is as gratifying as it is challenging. Ultrasonography remains the primary imaging modality for fetal imaging. Fetal MRI is used as a problem solving tool especially in cases of CNS and thoracic anomalies.Procedure Details: Patients underwent MRI in the following clinical settings: 1. When USG detected an anomaly for better delineation of the abnormality (e.g. ventriculomegaly on USG for evaluating brain parenchymal abnormality), or 2. When there was a high clinical suspicion of a fetal anomaly. (e.g. high recurrence risk for lissencephaly or polyhdramnios with no other abnormality on USG). Fetal MRI was performed using multiplanar T2 HASTE and T1 FLASH acquisitions. In this exhibit, we depict the cases where performing MRI allowed diagnosis of the complete spectrum of fetal anomaly or detected USG occult anomalies (e.g. tra-cheo-esophageal fistula) and impacted the decision of therapeutic termination or decided appropriate postnatal surgical care. We also discuss cases where despite a high genetic risk, normal fetal MRI allowed us to continue the pregnancy with good postnatal outcome.Conclusion: Fetal MRI has a definitive incremental role in decision making as regards continuation or termination of pregnancy when there exists a fetal anomaly or a high genetic risk of an anomaly.

C-399 The many faces of urolithiasis: A pictorial review A.S.R. Preto1, P. Sousa1, L. Guimarães2, J.T. Campos1, J. Gonçalves1, I. Ramos1; 1Porto/PT, 2Viseu/PT (sofiapreto@hotmail.com)

Learning Objectives: Review the state of the art in diagnosing flank pain due to suspected urolithiasis. Summarize the current use of nonenhanced CT and provide information on techniques and relevant findings. The role of the different imaging modalities in various patient subgroups will also be examined. The issues of radiation exposure and cost will be briefly examined.Background: Flank pain due to urolithiasis is a common problem in patients pre-senting to emergency departments. Radiology plays a vital role in the work-up of these patients. Many modalities can be used and will be discussed.Imaging Findings: Radiography is often used as a first step in examination of the patient suspected of having urolithiasis because the majority (90%) of urinary calculi are radiopaque. IVU has been almost abandoned. US shows calculi characteristi-cally as highly echogenic foci with distinct acoustic shadowing. Calculi as small as 0.5 mm may be detectable in optimal circumstances. The primary purpose of nuclear medicine imaging in cases of suspected ureteral obstruction is functional

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demonstration of the severity of obstruction. The nonenhanced MDCT of the abdo-men and pelvis for evaluation for ureteral calculi was developed as a response to the limitations of the previously described techniques.Conclusion: The development of MDCT has allowed imaging sections to be obtained with unprecedented thinness and spatial resolution. However, concerns

regarding radiation dose need to be considered, particularly in children and young adults. MR imaging has the inherent advantage over CT in that MR does not use ionizing radiation. Is this the future?

C-400 Preoperative pelvic lymph node detection: Diffusion weighted whole body imaging with background body signal suppression (DWIBS) increases the detection rate and reduces review time compared to conventional MR imaging W.M. Klerkx, W.B. Veldhuis, W.P.T.M. Mali, T. Takahara; Utrecht/NL (w.klerkx@umcutrecht.nl)

Purpose: Thorough histological analysis of lymphatic tissue often yields more lymph nodes (LNs) than can be detected with MRI. The aim of this prospective study is to evaluate whether DWIBS detects more pelvic LNs than conventional MRI, in less review time.Methods and Materials: Seventeen consecutive patients about to undergo pelvic lymphadenectomy, either for cervical (n=14) or low stage ovarian cancer (n=3), were included. Conventional T1- and T2-weighted images and DWIBS scans were acquired 2 weeks prior to surgery on a 3.0 T MR scanner. An experienced reviewer evaluated the presence of LNs in the bilateral obturator, external and common iliac regions. In addition, image review time was assessed. The results were analysed with frequency statistics and Wilcoxon signed ranks test.Results: All patients were confirmed to have negative LNs at histopathological examination. Totally 160 LNs were detected with conventional MRI, resulting in a median number of 9.0 3.1 (range 5-16) LNs per patient. The addition of DWIBS yielded 23 more LNs, i.e. 10.0 3.2 per patient, range 6-17, p=0.02. The evaluation time for DWIBS in addition to conventional MRI was on average 2:15 minutes less (7:30 vs. 5:15, p=0.04). At surgery, with surgeons blinded for conventional MRI and DWIBS results, a total of 435 (range 9-59) LNs were removed in these patients.Conclusion: DWIBS increases the detection rate of pelvic LNs by 14% compared to conventional imaging; in addition, DWIBS shortens the review time by 30%. However, even when DWIBS is used, 57% of LNs found at pathologic examination still go undetected.

C-401 Dose-reduced scan protocols according to individual body size: Cumulative unenhanced MDCT exposures in patients with flank pain from emergency S. Tartari, R. Rizzati, R. Righi, A. Deledda, K. Capello, G. Benea; Ferrara/IT (s.tartari@alice.it)

Purpose: To assess the dose of ionizing radiation delivered through dose-reduced scan protocol for suspected renal colic in normal and overweight-obese patients. To register incidence of repeated unenhanced CT (UHCT) examinations and the cumulative radiation dose delivered.Methods and Materials: For each patient undergoing UHCT, the body mass index (BMI) was calculated, separating patients into 2 groups: normal weight (BMI 25 kg/m2 - group 1); overweight and obese (BMI 25 kg/m2- group 2). For group 1 and group 2, protocols of our 64-row scanner prescribe tube current modulation set respectively at 70 mAs and 150 mAs (both groups: voltage 120 kVp; 2 mm nominal slice width with 1 mm slice increment). All UHCT examinations for flank pain from emergency performed over a 2-year period were included, registering multiplicity of examinations. The dose-length product (DLP) estimated for 100 randomly chosen UHCT examinations using manufacturer’s software was computed and converted to effective doses.Results:2.4 and 4.9 mSv for group 1 and group 2, respectively. Over a 2-year period, we performed 1026 UHCT examinations for urolithiasis; among these, 675 UHCT examinations from emergency were performed on 636 patients. A subset of 25 patients (3.7%) had two or more examinations, with estimated effective doses ranging from 4.9 to 19.6 mSv.Conclusion: Radiation dose is nearly double in overweight-obese patients. Patients with flank pain are at increased risk for serial UHCT. Use of low-dose protocol is mandatory to minimize radiation exposure.

C-402 Comparison of effective radiation doses of conventional and two-phase CT urography L.R. Williams, A. Smith, A. Hufton, A.J. Bradley; Manchester/UK (lukerobertwilliams@yahoo.co.uk)

Purpose: Multidetector CT urography (MDCTU) is emerging as the investigation of choice for diagnosing urothelial lesions. Concerns persist regarding the relative ef-fective radiation dose when compared to conventional intravenous urography (IVU). This radiation dose can be minimised by using only two acquisitions: non-contrast and combined nephrographic and excretory phases. The aim of this study was to compare the radiation dose of these two different techniques.Methods and Materials: Effective doses from a prospective sample of 33 patients undergoing IVU were calculated using the software programme PCXMC Version 1.5.1. Data inputted included actual X-ray field sizes and projections, patient height, weight and gender details and total dose-area product. For comparison, effective doses were also calculated from a prospective sample of 29 MDCTU patients using software available from the UK Imaging Performance Assessment of CT scanners (ImPACT) group. The software calculates organ and effective doses using details of the scanner model and technique factors (kVp, tube current, rotation time, beam collimation, pitch and scan range, average mA and acquisition time). All patients were scanned on the same 16 detector CT scanner.Results: The mean IVU effective dose was 2.44 mSv (range 1.0-6.9 mSv) (33 stud-ies), compared with 17.3 mSv (range 9.2-26.8 mSv) (29 studies) for MDCTU.Conclusion: The mean effective dose of MDCTU, using two acquisitions, was seven times higher than that of IVU. This difference in radiation dose should be given consideration when investigating urological symptoms. We will discuss pos-sible dose reduction strategies.

C-403 High resolution ultrasound in the assessment of stenosis of the urethra G. Argento, S. Petta, G. Scavone, G. Fabbri, A. Panetta, V. David; Rome/IT (gargento@sirm.org)

Purpose: To verify the diagnostic potentialities of high resolution ultrasound in the study of stenosing pathologies of urethra in comparison with conventional X-ray retrograde urethrography, considered as gold standard in pre-surgery imaging.Methods and Materials: Between 2005 and 2007, 12 patients affected by stenosis of urethra came to urologists’ attention and were selected for urethrotomic surgical treatment. They all underwent conventional X-ray urethrography with demonstra-tion of single or mutiple sites of stenosis of the urethra. Ecography studies were performed with Philips and Hitachi scanners with 12 MHz and 15 MHz high-reso-lution transducers. High resolution ultrasound studies were obtained before and after moderate fluid distension of urethral lumen with saline solution, with standard technique and with panoramic view (extended FOV).Results: In all 12 patients, US results were extremely precise in assessing the anatomical site and in the depiction of stenosis morphology, with exact reproduction of urethrographical X-rays findings. Moreover, US provided with valuable information about echostructural changes and alterations of soft spongious tissue of urethra, and the presence of microcalcifications and nodular or pseudonodular pathology; those elements are not detectable with standard X-ray contrast studies.Conclusion: High resolution ultrasound has demonstrated to be very effective in pre-surgical evaluation of Patient with stenosis of urethra selected for urethrotomy, in combination with conventional X-ray retrograde urethrography.

C-404 Adrenocortical adenomas and pheochromocytomas: Mass and enhancement loss evaluation at 140-second delayed contrast-enhanced CT T. Yamamoto, H. Sugimoto; Shimotsuke/JP

Purpose: To retrospectively measure the adrenal gland attenuation and the percentage loss of adrenal gland enhancement at delayed contrast medium-enhanced computed tomography (CT) in patients with adrenocortical adenomas and pheochromocytomas.Methods and Materials: Thirty-seven patients with proven adrenocortical adenoma and 15 with proven pheochromocytoma underwent helical CT. Nonenhanced CT was followed by contrast-enhanced CT 40 seconds and 140 seconds later. Attenuation and enhancement loss values were calculated.Results: The mean attenuation of adenomas (18 HU 16 [standard deviation]) was significantly lower than those of pheochromocytomas (44 HU 7) on nonenhanced CT scans (P 0.001). Although the mean attenuation values for pheochromocyto-mas were significantly higher than the value for adenomas on the 40-second delayed contrast-enhanced CT scans (P 0.001), there was more overlap in attenuation

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between adenomas and pheochromocytomas on contrast-enhanced scans than on nonenhanced scans. On the 140-second delayed scans, the mean attenuation of adenomas (58 HU 23) was significantly lower than that of pheochromocytomas (92 HU 17) (P 0.001). At optimal threshold values of 65 HU for attenuation at 140 seconds, the sensitivity for the diagnosis of pheochromocytoma was 100% and the specificity was 71% when pheochromocytomas were compared with adenomas. There was more overlap in the value between adenomas and pheochromocytomas on absolute percentage of enhancement loss.Conclusion: On nonenhanced and 140-second delayed scan, the mean attenuation value in adrenal adenomas is significantly less than that in pheochromocytomas. The 140-second delayed CT is useful in differentiating adrenal adenomas from pheochromocytomas.

C-405 Characterization of adrenal lesions by using chemical shift MRI: Comparison between 3.0 T and 1.5 T scanners in quantitative evaluation T. Namimoto, K. Awai, T. Nakaura, Y. Yanaga, Y. Yamashita; Kumamoto/JP

Purpose: The purpose of this study was to compare quantitative evaluation of the chemical shift MRI at 3 Tesla (T) with 1.5 T for the differentiation of adrenal adenomas from non-adenomas.Methods and Materials: We evaluated 53 patients (25 men, 28 women; mean age, 59.2 16.5 years) with unilateral (n=48) or bilateral (n=5) adrenal masses. We evaluated a total of 58 adrenal lesions (mean diameter, 2.7 2.0 cm). Histology (n=1) or clinical-imaging follow-up (n=44) demonstrated 45 adenomas. Histology (n=11) or clinical-imaging follow-up (n=2) demonstrated 6 pheochromocytomas, four metastases, one carcinoma, one pseudotumor and one hemorrhage. MR imaging was performed using the following breath-hold sequences: T1-dual- fast field echo (FFE) [repetition time (TR) 250 ms/double echo time (TE)=1.1/2.3 ms or 3.5/4.6 ms] at a 3 T scanner, T1-dual- FFE [TR 140 ms/double TE=2.4/4.8 ms] at a 1.5 T scanner. Axial imaging planes were used, with a slice thickness of 4 or 5 mm. MR images were quantitatively assessed for signal to noise ratio (SNR), calculated as [(signal intensity on in-phase imaging/(standard deviation on in-phase background noise)] and signal intensity index, calculated as [(signal intensity on in-phase imaging - signal intensity on opposed-phase imaging)/(signal intensity on in-phase imaging)].Results: The mean SNR at 3 T scanner was significantly higher than that of 1.5 T scanner (p 0.01). There was no overlap in signal indexes between adenomas and non-adenomas at 3 T scanner and 3 overlaps at 1.5 T scanner.Conclusion: The signal intensity index at 3 T scanner is the most reliable for dif-ferentiating adrenal adenomas from non-adenomas.

C-406 Multislice CT and MR imaging in the differentiation of adnexal masses A.C. Tsili, A. Charisiadi, C. Christakis, M. Doukas, D. Stefanou, E. Paraskevaidis, C. Tsampoulas; Ioannina/GR (a_tsili@yahoo.gr)

Purpose: To compare the diagnostic performance of multislice CT (MSCT) on a 16-slice CT scanner and MR imaging in the differentiation of adnexal masses in the same group of patients.Methods and Materials: Preoperative CT examination of the abdomen and MR imaging of the pelvis was performed in 67 consecutive women with clinically or sonographically detected adnexal masses. The CT examinations were performed on a 16-slice CT scanner and the protocol included scanning of the abdomen during the portal phase using a detector collimation of 16 X 0.75 mm and a pitch of 1.2. We used a 1.5-T magnet unit to perform T1, T2 and fat-suppressed T1-weighted sequences, before and after intravenous administration of gadolinium chelate compounds. The accuracy of MSCT and MR imaging in the differentiation between benign and malignant adnexal masses was evaluated using histopathologic results as the standard of reference. In characterizing adnexal mass lesions as benign or malignant, ROC analysis was also performed.Results: The sensitivity, specificity and accuracy of MSCT in the differentiation of adnexal masses were 90.5, 93.7 and 92.9%, respectively and that of MR imaging 95.2, 98.4 and 97.6%, respectively. On the ROC analysis, MR imaging proved slightly better than multislice CT (the areas under the curve were 0.921 and 0.982 for MSCT and MR imaging, respectively), but this was not proved statistically significant.Conclusion: Both multislice CT and MR imaging demonstrated satisfactory results in the characterization and differentiation of adnexal mass lesions.

C-407 MR imaging in differentiation of adrenal masses J. Zielonko, A. Babinska, M. Studniarek, R. Rzepko; Gdansk/PL

Purpose: The aim of the study is to evaluate the ability of MR imaging to differenti-ate adenomas from other adrenal masses using quantitative analysis of tumors’ signal intensity.Methods and Materials: Fifty four patients with 57 adrenal masses underwent MR imaging. Tumors were surgically determined as: pheochromocytomas (8), metastases (5), adrenal cortical carcinoma (1), and adenomas (24); 19 masses were diagnosed as adenomas on the basis of stability on imaging follow-up and the absence of clinical and endocrinologic dysfunction. Chemical-shift-weighted images (T1TFE sequence) and T2-weighted images (uTSE sequence) were used for quantitative analysis which included: T2 index (adrenal mass SI/ liver SI) and CSI ratio (adrenal mass SI on in phase image - adrenal mass SI on opposed phase image/ adrenal mass SI on in phase image). Statistical analysis was performed with Mann-Whitney U test.Results: Significant difference of T2 index between adenomas (mean 1.43 0.5) and pheochromocytomas (2.66 0.67) as well as between metastases (1.64 0.22) and pheochromocytomas was noted (p 0.05). Mann-Whitney U test revealed no significant difference of T2 index for adenomas vs metastases (p=0.1). CSI ratio was significantly different for adenomas (0.36 0.18) vs pheochromocytomas (-0.15 0.16) as well as for adenomas vs metastases (-0.23 0.26). No significant difference occurred in CSI ratios between pheochromocytomas and metastases.Conclusion: Quantitative methods based on calculated signal intensity ratios and indexes are helpful in differentiating adrenal adenomas from nonadenomas. In the presented investigation, CSI ratio in comparison with T2 index appears as a more reliable quantitative means of distinguishing adenomas from other adrenal tumors.

C-408 CT urography in patients with gross hematuria: Risk vs. benefit correlated to ageM. Sjöblom, P. Dahlman, L. Jangland, A. Magnusson; Uppsala/SE (malin.sjoblom@akademiska.se)

Purpose: Over the last decade the primary imaging modality in patients with gross hematuria has shifted from excretory urography to CT, which results in increased radiation doses. Radiation can cause cancer, the risk being strongly related to patient age. With rising age the risk of developing radiation induced fatal cancer decreases while the incidence of upper urinary tract malignancy increases. The aim of this study was to estimate the examination risk versus benefit in relation to age when examining the upper urinary tract with CT urography in patients with gross hematuria.Methods and Materials: All patients with gross hematuria referred for CT of the upper urinary tract during one year were included. Age and radiation doses in all patients were registered. The sample consisted of 176 patients. Mean age 66 16.5 (19-97). The risk of developing radiation induced fatal cancer was calculated. The number of upper urinary tract malignancies was registered.Results: The mean effective radiation dose per examination was 10.0 mSv 3.2 (2.8-21.3). The risk of developing radiation induced fatal cancer was 1/8230 when correlated to age and gender. CT detected a malignancy in the upper urinary tract in 1/20 patients. The frequency increased with age.Conclusion: Patients with gross hematuria examined with CT urography have considerably higher risk of having a malignancy in the upper urinary tract than of developing a radiation induced fatal cancer, especially when correlated to age.

C-409 Whole-body CT for detection and management of renal injuries in polytraumatized patients I. Díez, M. Boada, M. Febrer, M. Osorio, A. Gelabert, A. Maroto, M. Teixidor, S. Juanpere; Girona/ES

Purpose: We propose MDCT as the modality of choice in the evaluation, clas-sification and treatment planning of blunt renal trauma. To show the capabilities of MDCT in the evaluation of renal trauma in the polytraumatized patient also and to analyze and classify the renal injuries based on imaging findings.Methods and Materials: We retrospectively reviewed 835 consecutive polytrau-matized patients admitted in our hospital over a period of 37 months. Patients were included in a whole-body CT protocol with a 10MDCT (Philips). Images were analyzed with multiplanar reconstructions at the workstation. We used Federle clas-sification (imaging-based) for the staging and risk assessment (four types).Results: 37 of the 835 patients (4.43%) had renal injury, 42% type I, 20% type II, 37.5% type III and 0% type IV. Of the 37 patients, 8% had bilateral injury and 13.5%

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vascular damage. The incidence of renal injury in our series is lower than of other authors in literature (approximately 8-10%). This could be explained because the reviewed series included only blunt or penetrating abdominal injuries whereas in our study general polytraumatized patients were analyzed.Conclusion: MCDT plays a major role in diagnosing, classification and man-agement of renal injuries in polytraumatized patients, mainly in the detection of vascular damage.

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C-410 MR colonography in inflammatory bowel disease at 3.0 T. Correlation with conventional colonoscopy J. Rimola, S. Rodríguez, O. García, J. Panés, M. Pagès, C. de Juan, J.R. Ayuso, C. Ayuso; Barcelona/ES (jrimola@clinic.ub.es)

Learning Objectives: To provide a detailed step-by-step description of the tech-nique of MR colonography (MRC). To illustrate the spectrum of MRC findings in patients with inflammatory bowel disease (IBD) and their correlation with findings at conventional colonoscopy (CC). To discuss the advantages and limitations of MRC in patients with IBD.Background: CC is the gold standard for colorectal pathologies. However, submu-cosal and mesenteric involvements, which are common in IBD, cannot be assessed by CC. Therefore, the evaluation of the mucosa alone by CC may under represent the extent and activity of the disease. Also, CC is associated with the risk of several complications, mainly colon perforation or exacerbation in severe disease. MRC is a promising new modality that is useful in IBD since it allows the assessment of mural and mesenteric alterations.Procedure Details: Between October 2006 and August 2007, 50 patients with IBD were submitted to MRC performed with a 3.0 T MR scan unit. All patients had undergone a previous CC. We report step-by-step the methodology MRC procedure, its technical aspects, strengths and weaknesses of each sequence, and future directions of the technique. MRC findings and their correlation with CC (and, in some cases, with pathology) are illustrated and shown according to the type of IBD (Crohn’s disease or ulcerative colitis) and severity.Conclusion: MRC allows the evaluation of both IBD activity and extracolon com-plications. MRC findings show a good correlation with CC. MRC can be a feasible alternative method to CC for assessing IBD.

C-411 CT colonographic characteristics of early invasive colorectal carcinomas: Correlation with colonoscopic and pathologic findings M. Miyake1, G. Iinuma1, U. Tateishi1, T. Morimoto1, Y. Arai1, H. Taniguchi1, K. Sugimura2; 1Tokyo/JP, 2Kobe/JP

Learning Objectives: To illustrate CT colonographic characteristics and the mor-phological variety of colorectal carcinomas with submucosal invasion.Background: CT colonography (CTC) is an effective tool for detecting colorectal polyps. Today, small early invasive carcinomas are not rare in conventional colo-noscopy. Some of these lesions show flat and depressed morphology. These types are still unfamiliar in CTC, and it is essential to establish the CTC diagnosis. In this exhibit, we analyzed CTC images of 120 early invasive colorectal carcinomas acquired by 64-row MDCT, and assessed the images characteristics.Imaging Findings: This exhibit will review the CT colonographic characteristics and corresponding colonoscopic and pathologic appearance of a variety of early invasive colorectal carcinomas. We will focus on the lesion morphology and classify them into six types based on the virtual colonoscopic images (1: Typical polypoid type, 2: Eccentric polypoid type, 3: Semi-depressed or polypoid type, 4: Originally depressed type, 5: Lateral spreading type with villosity, 6: Flat lateral spreading type without villosity).Conclusion: CTC has a potential for detecting not only colorectal polyps but early invasive lesions including flat and depressed types. With the increasing use of CT colonography for colorectal carcinoma screening, radiologists are more likely to encounter early invasive colorectal carcinomas, and should pay more attention to the existence of the morphological varieties. It will help us in the detection of such important lesions and will enhance the efficacy of the screening with CTC.

C-412 Isolated infarction of the cecum R. Cytter-Kuint, D. Fisher, I. Hadas-Halpern; Jerusalem/IL

Learning Objectives: To describe the imaging features of isolated infarct of the cecum.Background: Isolated ischemia of the cecum is a rare entity. Causes are usually divided into vascular occlusive (thrombus, emboli, small vessel disease) or non-occlusive (low flow states, drugs). Patients usually present with acute right lower quadrant pain, diarrhea, nausea and vomiting. The physical examination is usually nonspecific. Differential diagnosis ranges from inflammatory processes to neoplastic or ischemic disease. The disease is managed conservatively. Between 1998 and

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2007, nine cases of isolated infarct of the cecum were diagnosed in our department. All patients suffered from heart disease. Three of them were dialysis patients. Six patients underwent colonoscopy and one patient was operated on.Imaging Findings: CT scans in all cases demonstrated circumferential thickening of the cecal wall, pericolic fat stranding and engorged mesentery. Changes were limited to the cecum. Atherosclerotic changes in the abdominal vessels were seen in all of the cases. As opposed to tumors, despite the wall thickening, the cecal mucosa seemed to be smooth. Ischemic changes were found in the pathology of four cases. In two other cases, sequential CT scans showed resolution of the findings and colonoscopy was performed only afterwards and was unremarkable.Conclusion: Isolated cecal infarct is usually a self-limited disease and should be considered in the differential diagnosis of right lower quadrant pain in the elderly, accompanied by focal cecal wall thickening on CT scan, especially in the pres-ence of risk factors.

C-413 Cecal volvulus: Radiological findings of a frequently misdiagnosed disease E. López-Pérez, P. Bartumeus, M.J. Martinez, L. Flors, G. Figueres, C. Leiva-Salinas; Valencia/ES (azulena@msn.com)

Learning Objectives: To describe the different imaging findings of cecal volvulus on plain abdominal radiograph, CT and barium enema. To illustrate the types of cecal volvulus and its differential diagnosis.Background: Cecal volvulus is a rare cause of intestinal obstruction. It is com-monly misdiagnosed because of its low frequency and the non-specific clinical and radiological findings. Accurate diagnosis is vital as delay in the diagnosis may lead to vascular compromise, intestinal ischemia and perforation. Between Febru-ary 1997 and March 2007, eight surgically proven cases of cecal volvulus were reviewed. We describe the different types of cecal volvulus, radiological findings and differential diagnoses.Imaging Findings: Ectopical dilated cecum, right lower quadrant empty, small bowel dilatation and absence of gas in the distal colon are the most frequent imaging find-ings on plain abdominal radiograph and CT. “Whirl” sign and “beak” sign are classic signs that suggest cecal volvulus on CT. Barium enema reveals the point of the obstruction as a “beak” sign or as a rounded termination of the barium column. The differential diagnosis of cecal volvulus includes sigmoid volvulus, midgut volvulus, small bowel obstruction, colon obstruction, gastric distension and paralytic ileus. There are two types of cecal volvulus, torsion type and cecal bascule.Conclusion: CT is a key imaging technique and it is the most useful procedure for identifying cecal volvulus, such as a fluid-filled cecum or a dilated cecum overlain by small bowel distension, when radiographic findings are obscured.

C-414 Appendix pathology: Far beyond acute appendicitis B. Nieto Baltar, Y. Martinez Alvarez, N. Arevalo Galeano, L. Grana Lopez, M. Ciudad Fernandez, E. Vano Galvan, J. Gredilla Molinero, A. Casado Lopez; Madrid/ES (nietba@yahoo.es)

Learning Objectives: To be familiar with the main tumoral and nontumoral condi-tions affecting the ileocecal area. To identify the main radiologic features that help differentiate between inflammatory and malignant processes of the ileocecal area. To show the CT and ultrasound appearances of appendiceal mucocele and to cor-relate them with their different pathologic meaning.Background: The appendix can present other pathologic processes aside from acute appendicitis. Although rare, appendiceal tumors can complicate (superinfec-tion, intussusception, pseudomyxoma peritonei and torsion) and present with acute abdominal symptomatology. Mucocele, one of the most frequent of this rare group, may have different pathologic meaning, from mucinous hyperplasia to mucinous cystadenocarcimoma and the surgical management ranges from appendicectomy to hemicholectomy.Imaging Findings: We have made a pictorial review showing and describing the CT and US imaging features of the appendiceal pathology, which were not acute appendicitis, found in our institution during the last 6 years. This includes mucocele, carcinoid tumour, non-Hodgkin´s lymphoma and adenocarcimoma. We analyze the sizes of the mucoceles, density, presence of calcifications, signs of complications or pseudomyxoma peritonei. We describe some imaging findings, which will guide us to a more specific diagnosis such as the kind of tumor and its possible complications, focusing on the differential diagnosis with other inflamma-tory processes in the same area.Conclusion: Although uncommon, primary neoplasms of the appendix often pro-duce clinical symptoms that may lead to imaging evaluation. CT will help rule out or confirm an appendiceal tumor and suggest a more specific diagnosis.

C-415 Effects of X-ray exposure on accuracy of digital cleansing in CT colonography Y. Miyatani1, Y. Hirano2, K. Shichinohe1, M. Yamazaki3, G. Iinuma1; 1Tokyo/JP, 2Hokkaido/JP, 3Aichi/JP (yoshiyuki.miyatani@glb.toshiba.co.jp)

Learning Objectives: To understand that the accuracy of digital cleansing varies with the scanning dose. To understand that the imaging capabilities for lesions after digital cleansing varies with the scanning dose. To recognize the factors that affect accuracy in CT colonography.Background: Accurate digital cleansing technique may permit the number of patient positions in conventional CT colonography to be reduced from two to one. It also has the significant advantage of reducing radiation exposure. The accuracy of digital cleansing is considered to be highly dependent on optimization of both the software algorithm and the scan protocol.Procedure Details: Simulated lesions ranging from 0.05 mm to 0.65 mm in height were made on the surface of an agar-phantom, which was placed in a container filled with dilute Gastrografin and scanned at various X-ray exposures. The ac-curacy of digital cleansing was improved with higher X-ray exposure. Additionally, the accuracy of digital cleansing was maintained with low-dose scanning by using dedicated noise-reduction software. The results of the phantom studies were ap-plied in clinical cases where the application of noise reduction software improved the detection of lesions submerged by tagged intestinal fluid.Conclusion: The accuracy of digital cleansing can be increased with noise-reduc-tion software, and the detection of lesions submerged by tagged intestinal fluid can be improved. The increased accuracy of digital cleansing may permit the number of patient positions in conventional CT colonography to be reduced from two to one and help to minimize radiation exposure and patient discomfort.

C-416 Accuracy of diffusion-weighted magnetic resonance imaging in detecting local recurrence of colorectal cancer: Initial experience K. Shuto, T. Aoyagi, G. Ohira, K. Narushima, H. Saito, A. Saito, T. Ota, T. Kazama, S. Okazumi; Chiba/JP

Purpose: To assess the accuracy of diffusion-weighted magnetic resonance imag-ing (DWI) in patients with local recurrence of colorectal cancer.Methods and Materials: Seventeen patients who were suspected of locoregional disease recurrence following colorectal resection with lymphadenectomy were enrolled. Contrast enhanced MDCT was performed at six-month intervals as part of the postoperative follow-up, and a localized lesion in the lower abdomen was detected in all of the patients. They underwent MR imaging including DWI and T2-WI imaging in cases of suspected recurrence. DWI in combination with T2-WI images were used to estimate the target lesion. The standard of diagnosis of true recurrence was made as follows: 1, histologically proven; 2, clinically increase in size after 3 months by MDCT. 15 patients were diagnosed as true recurrent. We evaluated the accuracy of DWI and compared the ADC value of the recurrent lesion with those of the normal colon and of the primary colorectal cancer in 20 other control patients who underwent DWI at the same period.Results: 14 cases were detected clearly on WDI. The sensitivity, specificity and accuracy rate of DWI were 93, 100 and 94%, respectively. There was a significant difference between the ACD value of the recurrent lesion and those of the normal colon (1.090 vs. 1.436, P=0.004); however, no difference was found between those of the primary cancer.Conclusion: DWI may enable accurate assessment of locoregional disease recur-rence of colorectal cancer. This noninvasive modality may become a valid clinical imaging of an initial evaluation during postoperative course.

C-417 MDCT-colonography: The value of the ratio between length and thickness of the involved segment of the colon in distinguishing neoplastic and inflammatory processes J.M. Pienkowska, E. Szurowska, J. Wierzbowski, G. Rompa, I. Marek, M. Dubaniewicz-Wybieralska, M. Studniarek; Gdansk/PL (jpienkowska@amg.gda.pl)

Purpose: MDCT colonography is used to evaluate colon cancer and inflammatory bowel disease (especially diverticulitis) in many cases. There is an overlap in the imaging appearance of these diseases in part of the exams. The aim of the study was the assessment of the ratio between length and thickness of the involved segment of the colon that may help in distinguishing neoplastic and inflammatory processes.Methods and Materials: A total of 74 selected patients with strongly clinical sus-

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picion of colorectal cancer (positive fecal occult-blood test, altered bowel habits, anemia of unknown cause, weight loss, abdominal pain) underwent MDCT-colonog-raphy. The length, thickness and the ratio between the length and thickness were estimated. All results were correlated with histopathological findings.Results: MDCT colonography correctly detected 44 cases of colorectal cancer and 18 inflammations. The lengths of the involved segment were 27-140 mm (mean 65.89) for colon cancer and 30-250 mm (mean 127.94) for inflammations. The wall thickening was 9-63 mm (mean 26.05) for neoplastic and 3-15 (mean 6.88) for inflammatory processes.Statistical analysis of the data showed that the ratio between the length and the thickness had the highest specificity for differentiation colon cancer from inflam-matory bowel disease (p 0.05). The ratio than 5.4 is characteristic for colon cancer (sensitivity 97.7%, accuracy 93.3%). The ratio than 5.4 is most specific for inflammatory processes.Conclusion: Evaluation of the ratio between length and thickness of the involved colon segment can be used as a precise indicator to differentiate between neoplastic and inflammatory processes.

C-418 Optimizing bowel preparation for multidetector row CT colonography: Comparison of three different cleansing preparations M.M. Slattery, E. Thornton, A. Keeling, M. Morrin; Dublin/IE (mlslattery@hotmail.com)

Purpose: Sodium phosphate (FleetPrep kit 1) is the main colonic cleansing agent utilized prior to CT colonography (CTC); however, concerns regarding safety have led to restriction in use. The aim of this study was to compare three bowel cleans-ing preparations, single-dose Sodium phosphate, 2 sachets sodium picosulphate (Picolax) with senna, and a combination of Picolax, senna and 1000 cc 2% oral diatrizoate meglumine (Gastrograffin) prior to CTC.Methods and Materials: Prospective study of sixty patients who received one of three preparations prior to CTC. Group 1 (n=20) received Sodium phosphate; Group 2 (n=20) received Picolax and senna; and Group 3 (n=20) a combination of Picolax and oral gastrograffin. The colon was segmentally evaluated and ana-lysed quantitatively regarding distension and residual fluid/faeces using 5-point scales. Overall preparation quality and diagnostic confidence between groups were assessed. Statistical analysis was performed using the Kruskall-Wallis test and Dunn’s post test.Results: Colonic distension scored similarly in all groups (p 0.05). There was significantly less retained fluid (p 0.05), and significantly more residual faeces (p 0.05) in subjects prepared using sodium phosphate. No significant difference in terms of residual fluid or faeces was observed between Groups 2 and 3 (p 0.05) and overall study quality was superior in subjects prepared with Picolax and senna (Groups 2 and 3) (p 0.05). Overall confidence in diagnosis was significantly higher where oral labelling with gastrograffin was performed (Group 3) (p 0.05).Conclusion: Picolax preparations are superior to sodium phospate preparation prior to CTC. The increased overall confidence in diagnosis in subjects who received a combination of Picolax and oral gastrograffin is attributable to the quality of labelling of residual fluid and faeces.

C-419 Can carcinoembryonic antigen be useful for preoperative computed tomography in colon cancer patients? R. Moutinho, H. Santos, P. Caldeira, G. Afonso, D. Neto; Faro/PT (Ric_moutinho@hotmail.com)

Purpose: Many surgeons agree that preoperative computed tomography (CT) provides information on the extent of the local disease and the presence of metastatic disease in colon cancer, but propose the use of CT scan only when metastatic disease is suspected. The purpose of this study was to assess the util-ity of carcinoembryonic antigen (CEA) as a predictor of the need for preoperative CT scan in colon cancer.Methods and Materials: 288 patients (171 men, 117 women) diagnosed with colon cancer between November 2003 and May 2007 were included in this retrospective study. CT findings were compared with chirurgical and pathological results and with preoperative CEA values in 288 patients.Results: The sensitivity of CT scan in predicting metastatic disease was 97%. There were 91% of stage IV patients who had an abnormal CEA ( 2.5 ng/ml). By using a CEA level of 2.6 ng/ml or above as a pre-requisite for pre-operative CT, 87 patients would not have had preoperative CT scans and 91% of the stage IV patients would have been imaged. By using a CEA twice the normal or above, 18% of the stage IV patients would not have been imaged.Conclusion: The routine use of CT in the work-up of colon cancer is controversial.

Previous authors have supported selective use of CT scan only in stage IV patients; unfortunately there is not a single laboratory test that unequivocally identifies patients with metastatic disease. According to our study, a preoperative CT scan should be obtained on those patients with a CEA value 2.6 ng/ml.

C-420 Evaluation of virtual colonoscopy by autodissection: Experience I. Kiss, A. Rosztóczy, A. Palkó, T. Wittmann; Szeged/HU (ildikokissdr@gmail.com)

Purpose: To compare the diagnostic value of virtual endoscopy with a new autodis-section program and conventional colonoscopy.Methods and Materials: 193 patients with abdominal pain and a history of colorectal cancer were studied during an 18 months period (143 women, 50 men, age 55 37 years) before conventional colonoscopy. During the evaluation the colon was divided into 6 segments (sigmoid colon, descending colon, splenic flexure, transverse colon, hepatic flexure, ascending colon with the cecum). Segments seen by both methods were compared. CT colonoscopy was performed with a 16 slice multislice instrument GE with low dose values. For the optimal distension of the colon, supine and prone positions were both applied. The radiologist was blinded to the colonoscopic results.Results: One thousand one hundred and fifty-three colonic segments were evalu-ated. One hundred and thirty-five pathologic findings were detected. These included 17 tumors, 39 polyps, 17 strictures and 62 diverticula. For the detection of colonic polyps larger than 5 mm, the sensitivity, the specificity, the positive and negative predictive values of virtual colonoscopy were 88.5, 99, 89, and 99 percent, respec-tively. For the detection of diverticula these were 95.2, 99.2, 74, and 94 percent. All tumors and strictures were detected.Conclusion: The evaluation of the colon by autodissection programme assisted virtual colonoscopy can be quickly performed. In addition, it was able to improve specificity and sensitivity of the method.

C-421 64-detector computed tomography in preoperative assessment of vascular anatomy of middle colic artery in left-sided colon cancer G. Lo Re, M. Galia, E. Grassedonio, G. Runza, T. Bartolotta, F. Coppolino, R. Lagalla; Palermo/IT (giuseppe.lore12@tin.it)

Purpose: Anastomotic leakage is a frequent complication of anterior resection in left-sided colon cancer. The blood supply of colorectal anastomosis site is essential to avoid the risk of anastomotic leakage, and the presence of an accessory middle colic artery, frequent variation rather of mesenteric vasculature, reduces this risk increasing the supply. The aim of this study is to evaluate the usefulness of Multi-detector Computed Tomography (MDCT) in the assessment of vascular anatomy of middle colic artery in order to reduce the risk of anastomotic leakage.Methods and Materials: B 70 patient underwent curative surgery at our hospital. In all cases, the MDCT was performed two days before the surgery. All scans were acquired at baseline and 30 and 75 seconds after intravenous administra-tion contrast medium at a rate of 4 mL/sec. After the axial images evaluation, raw dataset were elaborated in a workstation with MPR, MIP and 3D VR algorithms to evaluate the mesenteric vasculature, particularly with reference to presence of an accessory middle colic artery. In case of absence of accessory middle colic artery, the surgeon preserved a greater blood supply.Results: 61 patients (87%) showed conventional mesenteric vascular anatomy, and 4 of them (6.5%) experienced anastomotic leakage. In 9 patients (13%) it was possible to display an accessory middle colic artery, and no one of them experi-enced anastomotic leakage.Conclusion: Preoperative MDCT assessment of vascular anatomy of middle colic artery is useful in anterior resection of left-sided colon cancer in order to reduce the risk of anastomotic leakage.

C-422 Magnetic resonance imaging in the evaluation of sigmoid colonic geometric and mechanosensory properties J.B. Frøkjær1, D. Liao1, G. Dimcevski2, A. Bergmann1, A. Drewes1, H. Gregersen1; 1Aalborg/DK, 2Bergen/NO (frokjaer@mail.tele.dk)

Purpose: In many gastrointestinal disorders the mechanisms behind the symptoms are poorly understood. The aim was to use magnetic resonance imaging (MRI) to evaluate the three-dimensional (3D) geometry and mechanosensory properties of the sigmoid colon.Methods and Materials: The sigmoid colon was stepwise distended by a water-filled bag in eight subjects. Simultaneous 3D-MRI, bag pressure recording and sensory assessment were performed before and after smooth muscle relaxation

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with butylscopolamine. The inner and outer edges of the sigmoid wall were identi-fied semi-automatically. The surface distributions of principal curvature radii, wall thickness, tension, stress and the circumferential strain were calculated.Results: The geometry of the distended sigmoid colon was complex and the spatial distributions of the biomechanical parameters were non-homogeneous throughout the sigmoid surface. The circumferential length, strain, pressure and wall stress increased as function of bag volume (all P 0.001). In response to butylscopolamine, the pressure and wall stress was reduced (P 0.05) and the stress-strain curves were shifted to the right (indicator of tissue softening). The sensory response was a linear function of the biomechanical parameters (all P 0.001) and decreased in response to butylscopolamine as function of volume (P=0.02). The stimulus-response data indicate that the mechano-sensitive afferents are affected by smooth muscle tone.Conclusion: The present study utilises cross-sectional imaging for characterizing the complex geometry and mechanical properties of the sigmoid colon, including the role of smooth muscle tone. This method may be valuable in understanding the biomechanical and mechanosensory functions in colonic diseases (i.e. irritable bowel syndrome, ulcerative colitis and diverticular disease).

C-423 Should MDCT-colonography be a routine method in the post surgical follow-up of colorectal cancer in asymptomatic patients? J.M. Pienkowska, E. Szurowska, J. Wierzbowski, G. Rompa, I. Marek, M. Studniarek; Gdansk/PL (jpienkowska@amg.gda.pl)

Purpose: Colorectal cancer recurrence detected at an early stage in asymptomatic patients can be treated more effectively than advanced one. The aim of this study was the estimation of the role of MDCT-colonography as a routine method in patients after curative resection of colorectal cancer.Methods and Materials: 47 patients without known recurrence, who had a previ-ous partial colectomy for colorectal cancer, underwent regular follow-up MDCT-colonography with use of a standard protocol. The average age of the patients was 61 years (age range 28-83 years). The average time after surgery was 33 months (range 6-48 months). Colectomy involved the rectum (9 cases), sigmoid colon (22 cases), descending colon (4 cases) and the right colon (12 cases).Results: MDCT-colonography correctly detected local recurrence in two cases (one in sigmoid colon and one in rectum), and one metachronous cancer (in the transverse colon), not seen at conventional colonoscopy, due to post therapeutic stenosis of the anastomosis. In 4 patients liver metastases were identified, and in three recurrent diseases were seen in the retroperitoneal lymph nodes. Additionally, five polyps located in the colon proximal to the anastomosis were identified.Conclusion: MDCT-colonography can be useful as a routine method in the follow-up of asymptomatic patients, after surgically treated colorectal cancer. The method is able to detect local recurrences, metachronous tumors and distal metastases of colorectal cancer. It can be useful for planning further therapy.

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C-424 PET CT in oesophageal cancer: Pictorial essay and review of literature F. Grieve, K.C. Jackson, M. Prescott, B. Rajashanker; Manchester/UK (raja.shanker@cmmc.nhs.uk)

Learning Objectives: 1. To provide a pictorial review of the role of PET-CT in the diagnosis of oesophageal cancer. 2. Review of recent literature regarding the role of PET in local staging, detecting nodal and distant metastases and in detecting recurrent disease. 3. Discuss the several pitfalls in oesophageal cancer PET-CT imaging.Background: Endoscopic ultrasound and CT have been for long the methods of staging oesophageal cancer. Now PET-CT is being increasingly used to stage operable and also recurrent disease.Procedure Details: PET-CT is increasingly used in preoperative staging of eosophageal cancer. Though local staging of disease is best by endoscopic ultra-sound, PET-CT plays an important role in the diagnosis of synchronous lesions. Its usefulness in the evaluation of local nodal disease and in identifying M1B disease is variable. Distant metastases can also be identifed with PET-CT. It neverthless increases the accuracy of properative staging. The degree of SUV uptake also has been shown to be associated with disease prognosis.The review will contain illustrative examples with PET-CT in oesophageal cancer with pathological correla-tion. The pitfalls encountered are also discussed.Conclusion: PET-CT has an important role in routine preoperative staging of surgically resectable oesophageal carcinoma.

C-425 Esophageal and paraesophageal varices in cirrohsis: Imaging findings and endoscopic correlations I. Song, D. Choi, S. Kim, S. Lee, H. Rhim, W. Lee; Seoul/KR (ggabal@hanmail.net)

Learning Objectives: 1. To review literature on CT findings of esophageal and paraesophageal varices. 2. To evaluate MDCT features of esophageal and para-esophageal varices in our population (more than 300 patients). 3. To correlate them with endoscopic grading, EUS, and clinical manifestations.Background: Universal screening upper endoscopy is recommended for patients with cirrhosis to evaluate for the presence of esophageal varices. However, upper endoscopy to evaluate for the presence of esophageal varices in patients with cirrhosis is invasive and expensive, which limits its utility as a screening test. As a result, many reports regarding imaging findings of esophageal varices in the set-ting of liver cirrhosis were introduced. The basic imaging findings of esophageal varices are esophageal wall thickening, intraluminal protrusions or irregularities, and nodular enhancement within the wall. With these findings, however, esophageal varices cannot be differentiated from paraesophageal ones.Imaging Findings: On liver MDCT imaging, nodular or tubular enhancing lesions within the esophageal wall that contact the intraluminal surface possibly represent esophageal varices rather than paraesophageal varices. On the basis of those imag-ing findings, correlations between CT measurements of varix size and endoscopic grading were significant in our population.Conclusion: Routine liver MDCT for hepatocellular carcinoma screening is useful for the detection and grading of (para)esophageal varices

C-426 Caustic lesions gastrointestinal tract: Spectrum of multidector row CT findings S. Merola, A. Pinto, S. Romano, L. Romano, T. Cinque; Naples/IT (stefanella9@hotmail.com)

Purpose: The aim of this study is to illustrate the multidetector row computed to-mographic findings related to gastrointestinal caustic lesions and their significance for therapeutic decisions.Methods and Materials: From December 2004 to August 2007, we studied 26 patients with suspected gastrointestinal caustic lesions. Ten patients underwent thorax and direct abdomen X-rays. All 24 patients underwent multidetector row CT examination of the body.Results: The multidector row CT exam was negative in 5 cases; in 4 patients a light thickening of the oesophagus wall with normal enhancement was detected; in 5 cases thickening and sub mucous edema was diffused to the oesophagus and stomach; in 4 patients there was thickening and edema of the oesophagus and stomach without enhancement; in 2 cases there was a thickening of the oesophagus

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and a small gaseous peri-lumen nucleus. Two patients had sub mucous edema of the gastric wall; in 2 cases minuscule gaseous nucleus were detected at level of the portal vein with a parietal thickening of the stomach without enhancement; in 4 cases pneumoperitoneus was present.Conclusion: Gastrointestinal caustic lesions, when complicated with perforation, constitute a life-threatening condition. Knowledge of the CT signs of gastrointes-tinal caustic lesions has important implications for the role of imaging at the time of initial diagnosis.

C-427 Diagnosis of superficial esophageal squamous cell cancer with high-barium esophagography using flat panel X-ray detector: A pilot study H. Saito, K. Shuto, T. Ota, A. Sato, K. Narushima, T. Aoyagi, G. Ohira, S. Okazumi; Chiba/JP

Purpose: To evaluate the depth of invasion in superficial esophageal cancer with high-barium esophagography (HBE) by using FPD and to compare these X-ray findings with histological results.Methods and Materials: Twenty-six lesions of twenty patients of superficial esopha-geal squamous cell cancer who underwent radical esophagectomy or endoscopic submucosal dissection using the insultation-tipped diathermic knife were included in this study. Prior to surgery, HBE was performed with the double-contrast method. The depth of invasion was classified into two groups histologically, infiltration within mucosa (M group, N=14) and infiltration into submucosa (SM group, N=12). X-ray definitions were made by morphological findings as follows: aggregated nodular-ity, plaquelike appearance, ulceration and arched wall rigidity. We evaluated X-ray findings and compared them with histological results.Results: All lesions were detected on HBE with FPD (detectability 100%). The re-lationship of X-ray findings and histological results between M and SM groups were as follows: aggregated nodularity, 7% vs. 50%, P=0.0442 and scattered or absent in the remainder; plaquelike appearance, 7% vs. 50%, P=0.0442; ulceration 0% vs. 42%, P=0.0286; arched wall rigidity in the profile view, 14% vs. 67%, P=0.0197. If we define SM group as the presence over two X-ray findings, the sensitivity, specificity and accuracy were 75, 93 and 85% (P=0.0017), respectively.Conclusion: HBE with FPD may depict superficial esophageal cancer in detail and these morphological findings are valid features to discriminate between mucosal and submucosal superficial esophageal cancer lesions.

C-428 Evaluation of clinical findings and staging of esophageal cancer by using diffusion-weighted imaging T. Aoyagi, K. Shuto, G. Ohira, K. Narushima, A. Satoh, H. Saitoh, T. Ohta, H. Shimada, H. Matsubara, T. Kazama, N. Yanagawa, S. Okazumi; Chiba/JP

Purpose: The purpose of this study is to assess the clinical staging of esopha-geal cancer by DWI calculating the ADC. Also we compared with tumor’s ADCs and standardized uptake value (SUV) of fluorodeoxyglucose-positoron emision tomography (FDG-PET).Methods and Materials: 86 consecutive patients of esophageal squamous cell cancer participated in this prospective study. DW images were acquired using a 1.5 T whole body scanner equipped with a phased-array body coil. A single shot spin-echo type of echo-planar sequence that provided diffusion weighting in the direction of slice selection was used to obtain DW images. The corresponding b-value to diffusion-sensitizing gradients were b=0, 1000 s/mm2.Results: We recorded a negative correlation between the ADC of the tumors and tumor diameter (P=0.0044). Also we recorded a negative correlation between the ADC of the tumors and serum squamous cell carcinoma antigen (P=0.0042) and SUV of the FDG-PET of them (P=0.0347). We compared with ADC among clinical staging (clinical T1, cT2, cT3 and cT4). There were remarkable significant differ-ences between T1 and T3 (P=0.0003), T1 and T4 (P=0.0009). Comparison of ADC between clinical N staging, there was a remarkable significant difference between N0 and N1 (P=0.0002). Also comparison of ADC among clinical TNM staging, the ADC of clinical Stage I, cStageII, cStage III and cStageIV were decreased significantly than that of early stage.Conclusion: A statistically significant correlation of ADC value was recognized among clinical findings. This non-invasive modality could be a valid clinical imaging method for diagnosing the advanced level of esophageal cancer.

C-429 Diffusion MRI for prediction of response of esophageal cancer to chemoradiotherapy T. Aoyagi, K. Shuto, G. Ohira, K. Narushima, A. Satoh, H. Saitoh, T. Ohta, H. Shimada, H. Matsubara, T. Kazama, N. Yanagawa, S. Okazumi; Chiba/JP

Purpose: To evaluate the predictive value of apparent diffusion coefficient (ADC) on therapy outcome of combined chemoradiation in patients with primary advanced esophageal cancer using diffusion-weighted magnetic resonance imaging (DWI).Methods and Materials: We measured mean tumour water ADC before and after chemoradiation (CRT) in thirty patients with locally advanced esophageal squamous cancer. DWI was performed using a 1.5 T whole body scanner equipped with a phased-array body coil. A single shot spin-echo type of echo planar sequence that provided diffusion weighting in the direction of slice selection was used to obtain DW images. The corresponding b-value to the diffusion sensitizing gradients were b=1000 s/mm2. We evaluated the DW images measuring ADC value of the tumor and compared with the effect of CRT. The therapeutic effect was assessed according to WHO criteria using contrast enhanced MDCT and esophagography 3-4 weeks after the treatment.Results: Seventeen patients were responders and thirteen were non-responders. All tumors were detected by DWI (accuracy 100%). The mean ADC value of the tumor was significantly lower than that of the normal esophagus (1.004 x 10-3 mm2/s vs 1.756 x 10-3 mm2/s, p 0.0001). The mean ADC value of the responder group was significantly higher than that of non-responder group (1.114x10-3 mm2/s vs 0.878x10-3 mm2/s, p=0.0079).Conclusion: The mean ADC might be a new quantitative parameter to predict therapy outcome of combined preoperative chemoradiation in patients with primary esophageal squamous cell cancer.

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Peritoneum

C-430 Peritoneal mesotheliomas and mimickers: In-depth review of various clinicopathologic features and radiologic findings J. Park, K. Kim, H.-J. Kwon, M. Kim, G. Kwon, Y. Shin; Seoul/KR (zzzz3@hanmail.net)

Learning Objectives: 1. To recognize the diverse subtypes of peritoneal mesothe-liomas. 2. To discuss the clinicopathologic features, radiologic findings, and major differential diagnosis of each subtype of peritoneal mesotheliomasBackground: Mesotheliomas are rare neoplasms that arise from the mesothelial cells forming the serosal membranes of the body cavities. Second common to the pleural cavity, mesotheliomas may involve the peritoneal cavity, either solely or in combination with pleural involvement, and the incidence has been varied among the reports, approximately up to 30-45% of cases. Pathologically, peritoneal mesothelio-mas are subdivided into diverse subtypes; the clinicopathologic features, radiologic findings, and major differential diagnosis are varied among these subtypes. In this exhibit, we review the clinicopathologic features of peritoneal mesotheliomas, il-lustrate their radiological findings, and discuss the differential diagnosis.Imaging Findings: 1. Classification of peritoneal mesotheliomas 2. Clinicopatho-logic features, radiologic findings, and major differential diagnoses of each subtype. The subtypes of peritoneal mesotheliomas are: 1) malignant mesotheliomas (dif-fuse, localized, solitary pattern, and unusual location); 2) cystic mesotheliomas (unilocular, multilocular, malignant transformation); 3) well-differentiated papillary mesotheliomas; 4) adenomatoid tumors; 5) solitary fibrous tumors.Conclusion: It is important to be aware of the clinicopathologic features and radiologic findings of peritoneal mesotheliomas because it may help radiologists narrow the range of differential diagnosis and increase the chance of accurate noninvasive diagnosis.

C-431 CT manifestations of peritoneal carcinomatosis: A pictoral review F.H. Peters, D. Boone; London/UK

Learning Objectives: 1. Review of the pathways of peritoneal seeding. 2. Demon-strate the typical sites of peritoneal disease. 3. Recommend an approach to review-ing the peritoneal spaces in cases of suspected peritoneal carcinomatosis.Background: Peritoneal dissemination of malignancy is directly related to the dynamic circulation and pooling of ascitic fluid within the peritoneal recesses and consequent seeding of malignant cells. Recognition of these peritoneal spaces and their anatomical boundaries together with an understanding of the transcoelomic flow of fluid within the abdominal cavity can aid in the interpretation of CT findings. This is of importance to the diagnostic radiologist involved in the treatment of a variety of malignancies with a propensity to spread via the peritoneal cavity.Imaging Findings: Following our experiences in a large teaching hospital, we highlight both the typical and more atypical appearances of peritoneal carcino-matosis using modern CT scanning technology. We describe a simple, systematic approach to reviewing the major peritoneal spaces based on our personal experi-ences and those outlined in the literature with emphasis on certain pitfalls in image interpretation.Conclusion: Knowledge of the peritoneal anatomy together with an understand-ing of the mechanisms of peritoneal seeding aids interpretation of CT findings in abdominoperitoneal carcinomatosis. This can be further simplified with the aid of a systematic approach to the review of the peritoneal spaces.

C-432 The peritoneal cavity and omentum on CT: The key to many intra-abdominal pathologies J. Kuriakose, S. Sinha, R. Gadahadh, C.J. Corr; Wrexham/UK (connor.corr@new-tr.wales.nhs.uk)

Learning Objectives: 1. To emphasise the importance of carefully examining the intra-abdominal fat in abdominal CT. 2. To illustrate how findings in the peritoneum and omentum often lead to the correct diagnosis. 3. To demonstrate the range of pathologies that produce important findings in the peritoneum and/or omentum.Background: The abdominal organs are surrounded by peritoneum and omentum, and these structures are often involved in intra-abdominal pathology originating in any abdominal or pelvic organ. The peritoneum and omentum should be assessed routinely in every abdominal CT as it often contains extremely helpful findings. However, it is often the site of missed diagnosis on CT, and this poster aims to re-emphasise the importance of examining the abdominal cavity on CT.

Imaging Findings: We present many cases of abdominal CTs which demon-strate important findings in the peritoneum or omentum, which lead to the correct diagnosis. Often the peritoneal findings are the only sign, or the most important sign. Several of these findings were initially missed, and we will demonstrate the importance of looking for peritoneal disease in many situations. We present cases of inflammatory and malignant diseases, acute and chronic diseases, and diseases of the GI tract, GU system, and diseases of the peritoneum itself.Conclusion: Careful examination of the peritoneal cavity and omentum on abdomi-nal CT is vital to help the radiologist reach the correct diagnosis in a wide range of intra-abdominal pathology.

C-433 Encapsulating peritoneal sclerosis: Spectrum of sequential computed tomographic findings K. Furuya1, I. Sakino2, K. Yasumori1, M. Nakamoto2, T. Yanagida2, C. Yasunaga2, T. Muranaka1; 1Fukuoka/JP, 2Kitakyushu-City/JP (Kymfuruya@aol.com)

Learning Objectives: To demonstrate a wide variety of successive follow-up CT images of encapsulating peritoneal sclerosis (EPS) in patients on continuous am-bulatory peritoneal dialysis (CAPD) from early to advanced stages. To correlate CT findings with patient clinical characteristics and pathological findings in actual cases. To assess the diagnostic value of updated CT in the evaluation of EPS.Background: Encapsulating peritoneal sclerosis (EPS) is a clinical entity character-ized by persistent, intermittent, and/or recurrent symptoms due to adhesive bowel obstructions that come from wide adhesions of the diffusely thickened peritoneum. Though it is one of the most serious complications of continuous ambulatory peri-toneal dialysis (CAPD), the early clinical features are nonspecific and diagnosis is often made only at a late stage. 12 patients on CAPD with EPS underwent repeated sequential CT examinations at our institution. The CT follow-up period was 5 months to 9 years. In this exhibit, we demonstrate a wide variety of sequential follow-up CT findings and correlate them with patient clinical characteristics.Imaging Findings: Early EPS showed massive or locculated ascites, vascular engorgement, and increased attenuation of the omentum and mesentery. As the disease progressed, the sequential images clearly showed thickening of the peri-toneum, peritoneal calcification, wall thickening and tethering of the small bowel, an encapsulated intestinal loop, and bowel obstruction. Some of these findings improved in patients whose treatment was effective.Conclusion: The CT images reflect the progression and improvement of EPS well. Awareness of these CT manifestations will help to enable correct diagnosis for early treatment.

C-434 Extraparenchymal supramesocolic cystic lesions: Radiologic features A. Piazza, M.A. Pastrana, M.P. Reyero, P. Fraga, C. Garcia Roch, L. Arrieta; Madrid/ES

Learning Objectives: To review and analyze those pathologic entities that can manifest as extraparenchymal supramesocolic cystic lesions (ESCL) in adults and to establish radiologic features for their diagnosis using CT and MR images.Background: The transverse mesocolon divides the peritoneal cavity into supra-mesocolic and inframesocolic compartments. We offer a wide differential diagno-sis of diseases causing extraparenchymal cystic masses in the supramesocolic compartment, using CT and MR images that illustrate the characteristic findings of each pathologic entity.Imaging Findings: A longitudinal, retrospective, observational, non-randomized and analytical study was performed. It included patients referred to our institution in the last 5 years who underwent 16-detector-row CT (Siemens Sensation 16®, Erlangen, Germany) and/ or 1.5 Tesla MR (Siemens Magnetom Avanto®, Erlangen, Germany) studies. An imaging-based differential diagnosis atlas of ESCL, includ-ing congenital, inflammatory and neoplastic lesions was created, emphasizing its most relevant features.Conclusion: CT and MRI are reliable tools that can help establish the location and characteristics of ESCL, thereby achieving a confident diagnosis of these masses. We offer an imaging-based differential diagnosis atlas of ESCL containing CT and MR illustrations to assess radiologists when reporting these lesions.

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C-435 Analysis of mesorectal fascia and mesorectum by 64-detector CT: Detectability of mesorectal fascia and influence of rectal contrast administration on mesorectal thickness M. Champfailly, B. Scotto, P. Omoumi, D. Alison; Tours/FR (pomoumi@yahoo.fr)

Purpose: To evaluate the dectectability of mesorectal fascia by 64-detector CT and the influence of rectal contrast administration on mesorectal thickness in patients without any rectal pathology.Methods and Materials: We retrospectively reviewed the CT examinations of 79 consecutive patients randomly divided into two groups: one group of 40 patients with rectal contrast administration and another of 39 patients without rectal con-trast. The mesorectal fascia and the mesorectal thickness were evaluated on strict axial cuts at the level of sacro-coccygeal junction. The first radiologist measured the mesorectal thickness at 12, 3, 6 and 9 o’clock. The measurements for the two groups were compared using a two-sided Student’s t test ( =5%). The measure-ments of the 20 first examinations were independently repeated by a second radiologist and compared to those obtained by the first observer using a paired two-sided t test ( =5%).Results: The mesorectal fascia was visible on 314 quadrants among the 316 quadrants in total (four quadrants in 79 patients). There was no significant differ-ence between the measurements obtained by the two observers at 12 (p=0.219), 3 (p=0.709), 6 (p=0.504) and 9 o’clock (p=0.767). Mesorectal thickness was significantly lower at 3 (p=0.0065), 6 (p 0.001) and 9 o'clock (p 0.001) on the examinations performed with rectal contrast administration.Conclusion: 64-detector CT allowed good detection of the mesorectal fascia and could potentially substitute MRI for the preoperative locoregional staging of locally advanced rectal carcinoma (T3 and T4). Rectal contrast administration leads to significantly lower mesorectal thickness, and hence possibly underestimating the circumferential resection margin.

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C-436 Radiotherapy for rectal cancer: The role of imaging J. Liaw, A. Nikapota, R. Glynne-Jones, V.J. Goh; Northwood/UK (jvpliaw@hotmail.com)

Learning Objectives: 1. To provide an overall view of current radiotherapy treatment of rectal cancer including the evidence base. 2. To illustrate how imaging influences radiotherapy planning including scheduling. 3. To illustrate the use of functional imaging techniques for radiotherapy planning and to assess therapeutic effect. 4. To highlight post radiotherapy complications and its management.Background: Preoperative radiotherapy or chemoradiotherapy diminishes the relative risk of local failure following surgery by more than 50%. Accurate pre-opera-tive imaging is necessary for appropriate patient selection and accurate planning particularly as radiotherapy treatment has become more sophisticated. Functional imaging techniques have also become more important both for the assessment of therapeutic effect and for radiotherapy planning.Imaging Findings: This review will provide an overview of current treatment of rectal cancer and highlight pertinent imaging for accurate planning. More innovative imag-ing approaches that are being applied for rectal cancer will be discussed including DCE-MRI, diffusion weighted, and BOLD-MRI, perfusion CT as well as FDG-PET-CT. Imaging and management of treatment complications will be illustrated.Conclusion: Pre-operative radiotherapy or chemoradiation is now established as standard care for locally advanced rectal cancer. Imaging has an important role to play not just for staging, but also for radiotherapy planning and for therapeutic assessment of rectal cancer.

C-437 Rectal carcinoma after therapy: MR imaging findings M. Arias González, A. Iglesias Castañón, J. Mañas Uxó, I. Carcacia Hermilla, M. Herreros Villaravitz; Vigo/ES (mercedes.arias.gonzalez@sergas.es)

Learning Objectives: 1) Anatomy of the rectum with MRI correlation. 2) Different surgical approaches and MRI findngs. 3) Complications after both surgery and radiotherapy on MRI. 4) Differentiation of recurrence from local complications.Background: MRI plays an important role in the follow-up of treated rectal carci-noma. Common post-treatment changes should not be mistaken with post-treat-ment complications or disease recurrrence. Between January 2004 and August 2007, 50 patients with treated rectal carcinoma were studied and followed in our center using MRI.Procedure Details: Conventional MRI pelvic study using T2- and T1-weighted images was completed in every patient with a dynamic 3D GRE T1 weighted sequence performed after contrast administration. Pharmacokinetic analysis of the data was done in every patient showing significantly higher enhancement in cases of recurrence (P 0.05).Conclusion: Accuracy in the diagnosis of recurrent rectal cancer is 75% using conventional sequences. Using dynamic contrast-enhanced T1-weighted MR imaging and pharmacokinetic analysis, the accuracy in diagnosing rectal cancer recurrence rises to 90%. Familiarity with the appearance of post-treatment appear-ances and common complications, and with the patterns of disease recurrence is a prerequisite to accurate interpretation of MR scans in the follow-up of patients with treated rectal carcinoma.

C-438 Could MRI assess the effect of long-course chemoradiotherapy on the morphologic features of primary rectal cancer? I. Miucin-Vukadinovic, N. Prvulovic, M. Spirovski, B. Bokorov, A. Zvezdin; Sremska Kamenica/RS (mmiuchin@neobee.net)

Purpose: To use MRI to compare the morphologic features of rectal carcinoma before and 6 weeks after chemoradiatiotherapy and to correlate posttreatment MRI appearance with the histologic findings in resected tumors.Methods and Materials: MRI was performed in 48 patients before and immediately after a standardized 5-weeks course of chemoradiotherapy. Morphologic features and tumor changes were evaluated with respect to primary tumor and nodal downsizing and downstaging. The MRI findings after chemoradiation therapy were compared with the histologic findings with respect to prediction of tumor stage and showing the distance of the tumor from the circumferential margin.Results: Decreases in tumors size of more than 30% occurred in 68.7%. Changes in MRI T stage occurred in 25.1%. Tumor regression from the circumferential

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resection margin was found in eight patients, all findings confirmed at histologic examination. Nodal downsizing was in 70% patients while downstaging was revealed only in 18.8% patients. 45.3% patients were node free on both MRI findings and histologic results. For the all-tumors group, 66% of tumors were correctly T staged after treatment. All 24 patients with tumors radiologically staged T3 radiologically predicted to have a clear circumferential resection margin, and these findings were confirmed at histologic examination. Overall prediciton of distance between tumor and circumferential margin was good, with a mean difference of -0.3 mm.Conclusion: MRI showed decreases in tumor size and nodal downstaging after chemoradiotherapy in 83% of patients. The clinically more important circumferential resection margin can be predicted with high accuracy and consistency allowing preoperative radiotherapy.

C-439 Characteristics of rectal gastrointestinal stromal tumors on MRI and CT Z. Jiang, W. Peng, Y. Shi, X. Li; Shanghai/CN (issyjiang@yahoo.com.cn)

Purpose: Rectal gastrointestinal stromal tumors (GISTs) are relatively rare and rep-resent less than 5% of all GISTs throughout the gastrointestinal tract. The purpose of our study was to characterize the MRI and CT findings of rectal GISTs.Methods and Materials: MRI and CT images of 12 patients with a pathologically proven rectal GIST were retrospectively evaluated and compared with histological findings.Results: All rectal GISTs were found in the lower two-thirds of the rectum. Exophytic growth pattern was seen in the majority of the tumors (9/12). The largest diameter of tumors ranged from 3 to 18 cm (mean, 8.5 cm), and extramural tumors are larger than intraluminal tumors, averaging 9.8 cm vs 4.6 cm. Nine tumors showed a well-defined margin, whereas 3 tumors showed contour irregularity or blurring, MRI revealed invasion into the prostate gland in 2 cases. On CT images, most of the tumors (5/7) were heterogeneous with cystic change, and flecks of calcification were dectected in 2 masses. Seven patients underwent MRI; all these 7 tumors were heterogeneous, with hyperintense foci on T1WI representing hemorrhage (2/7) and hyperintensity on T2WI corresponding to necrosis (7/7). Ulceration to the rectal lumen was seen in 1 patient. Gradual intermediate enhancement was shown on multiphasic contrast-enhanced MRI in all these 7 tumors. Abdominal adenopathy and hepatic metastasis were not seen in any patient.Conclusion: Rectal GISTs are typically large, well-circumscribed heterogeneous tumors, and tend to have an exophytic growth pattern.They can have intratumoral degeneration, such as necrosis, hemorrhage, and calcification. Lymph node me-tastasis is very uncommon.

C-440 Inter- and intra-observer variation of two- and three-dimensional anal endosonography in the evaluation of recurrent anal cancer A. Christensen; Copenhagen/DK (anderschristensenemail@hotmail.com)

Purpose: The aim of this study was to evaluate the inter- and intra-observer agreement of 2-D and 3-D anal endosonography in the detection of recurrent anal carcinoma.Methods and Materials: This retrospective study includes 36 patients treated for anal carcinoma who were investigated using 3-D endosonography at Rigshospitalet from July 2001 to January 2005 because of suspected local recurrence. The 3-D scannings were reviewed from the hard disc by two observers that twice reviewed all 2-D examinations (the axial projection) as well as all 3-D examinations (the axial, as well as the reconstructed coronal and sagittal projections). The observ-ers scored each examination according to the following scale regarding presence of local recurrence: 1: No finding/benign findings, 2: Properly benign findings, 3: Suspicious findings/malignant findings. Kappa-statistic was used to evaluate inter-and intra observer variation of both 2-D and 3-D endosonographies.Results: Three-dimensional endosonography achieved better inter-observer agree-ment than 2-D endosonography: kappa 3-D 0.34-047 vs. kappa 2-D 0.15-0.28. This was also the case for intra-observer agreement: kappa 3D 0.34-0.62 vs. kappa 2-D 0.22-0.28. These differences were found to be significant with p 0.05.Conclusion: Three-dimensional endosonography proved to have significantly better inter- and intra-observer agreement than 2-D endosonography concerning detection of recurrent anal cancer. But neither modality achieved an excellent level of agreement properly because the endosonographic discrimination between tumour and radiation sequelae is difficult. Three-D endosonography seems to be less dependent of the individual examiner than 2-D endosonography.

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Small Bowel

C-441 Spectrum of CT findings illustrating gastro-intestinal complications associated with haematopoietic stem cell transplantation M. Schmit; Tübingen/DE (Marc.Schmit@gmx.de)

Learning Objectives: To illustrate the characteristic CT findings of bowel damage in patients undergoing haematopoietic stem cell transplantation (HSCT).Background: Complications due to drug toxicity, infectious agents and graft versus host disease (GVHD) remain major obstacles to the success of HSCT.Imaging Findings: Mucosal barrier injury (MBI) is the result of regimen associated drug toxicity. CT-findings in MBI include bowel wall thickening or mosaic perfusion with segmental or diffuse GI-tract involvement. Neutropenic colitis is characterized by edema and inflammation of the cecum and ascending colon, sometimes also involving the terminal ileum, CT images typically demonstrate cecal wall thicken-ing with hyperemia and moderate inflammatory stranding. The most consistent CT finding in acute GVHD is abnormal mucosal enhancement of the entire GI-tract with emphasis on the small intestine. Chronic GVHD of the GI-tract generally shows little or no abnormalities at imaging. Pseudomembranous colitis manifests as dif-fuse colonic involvement with marked eccentric or circumferential wall thickening. CMV colitis characteristically manifests as cecal wall thickening with contiguous involvement of the terminal ileum and ascending colon. Mucosal ulcerations are frequent and appear round or serpiginous. Candidiasis, Aspergillus and Mucora-les typically cause infections in patients with severe and prolonged neutropenia. Contrast-enhanced-CT findings show diffuse circumferential wall thickening with areas of both intense and poor contrast enhancement.Conclusion: Although some overlap exists in the CT appearance of the different causes of bowel-wall inflammation associated with HSCT, the location and the extension of the involved bowel segments, as well as accompanying findings, help in narrowing the differential diagnosis.

C-442 Primary and secondary neoplasms of the small bowel: Appearance on MRI and MDCT M. Anzidei, A. Napoli, P. Sedati, B. Cavallo Marincola, K. Lanciotti, C. Zini, P. Di Paolo, C. Catalano, R. Passariello; Rome/IT (mikilgenio@hotmail.com)

Learning Objectives: 1. To illustrate small bowel anatomy and to review the avail-able imaging techniques (sequences, scan protocols, oral contrast agents) with MRI and MDCT. 2. To describe imaging findings and differential diagnosis of the most frequent primary and secondary neoplasms of the small bowel on MDCT and MRI images in correlation with gross pathology. 3. To emphasize the use of MDCT and MRI in the surgical planning of small bowel neoplasms.Background: Radiologic evaluation of the small bowel anatomy relied for a long time on conventional contrast radiography; nowadays the technical improvement of MRI and MDCT has led to substantial improvement of the clinical impact of imaging. Accurate evaluation of anatomy, morphology and relationships with near structures is pivotal for therapeutic planning of small bowel neoplasms.Procedure Details: An extensive description of the different techniques available to perform cross-sectional imaging of the small bowel is presented. Patient preparation, choice of oral contrast agents, contrast administration protocols and scanning proce-dures (post-contrast delays, MRI sequences, post-processing techniques) are reviewed. The most significant findings of common primary and secondary neoplasms of the small bowel and their correlation with pathology are presented, covering lymphoma, adenocarcinoma, gastrointestinal stromal tumours, carcinoid and metastases.Conclusion: MRI and MDCT have substantially replaced contrast radiography for the evaluation of small bowel neoplasms. Extensive knowledge of technical details and imaging protocols, as well as relevant pathologic signs, is mandatory to perform properly and interpret each examination.

C-443 Indications, results and limitations of dedicated MDCT exam of the small bowel in the inflammatory disease: A comparison of two methodologies (enteroclysis and enterography) S. Romano, T. Cinque, G. Tortora, P. Lombardo, F. Maisto, L. Romano; Naples/IT (stefromano@libero.it)

Learning Objectives: To illustrate the essential findings of the imaging procedures. To compare the potential effectiveness of enteroclysis and enterography techniques in the MDCT study of the small bowel for inflammatory bowel disease. To describe the results and limitations of both imaging techniques.

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Background: There is a great debate about the efficacy of enterography with re-spect to the enteroclysis procedures in the MDCT study of the small bowel In this exhibit, we will describe the use of both techniques in the MDCT study of patients with abdominal pain from inflammatory bowel disease, the indications, findings, results, main advantages and limitations based on a series of 156 patiens.Procedure Details: MDCT enteroclysis exams were performed after distension of the intestinal loops by neutral or negative contrast medium introduced through a naso-jejunal probe. Enterography exams were performed after administration of peroral contrast solution (solution of idrosoluble iodinated contrast medium or water). Intravenous administration of contrast medium was performed in 148 patients. Post-processing multiplanar reconstruction was performed at a dedicated workstation. Findings considered: distension of the intestinal lumen, gross appearance and number of segments not distended, stenosis, parietal appearance, presence of extraparietal abnormalities, evidence of fistula, presence of lymphoadenopathy and evidence of multiple foci of disease. In all cases, correlation with definitive clinical and/or surgery findings was made.Conclusion: MDCT enteroclysis appeared to have a higher efficacy in diagnostic accuracy of inflammatory bowel pathology in patients with unknown disease and also of early stage.

C-444 3.0 T MRI for assessment of disease activity in Crohn’s disease J. Zhu, J. Xu; Shanghai/CN (billzhu49@hotmail.com)

Learning Objectives: To evaluate the role of 3.0 T MRI in predicting the disease activity of Crohn’s disease.Background: Crohn’s disease is characterized by remitting and relapsing episodes. A lot of studies on 1.5 T MR indicate that MR imaging is useful in assessing the activity of Crohn’s disease. Twenty-eight patients in our hospital who had clinically suspected exacerbation of Crohn’s disease were prospectively examined using 3.0 T MR. All patients were scored using the Crohn’s disease activity index.Imaging Findings: 2000 ml of mixed fluid was given orally and an antispasmodic drug was given before imaging. Images were obtained using T1W/FFE/IP, DYN/3D/T1W, T2W/SSh/TE80, T2W/SSh/SPIR, DWI/SSh on PHILIPS Achieva 3.0. Images were assessed by two radiologists who were unaware of the patient’s symptoms,

clinical scoring, and other imaging tests, and who reached a consensus about the imaging findings determined the absence or presence of active disease in each patient. 3.0 T MR imaging had an overall sensitivity of 93% and a specificity of 75% for active disease. The images of DWI have a sensitivity of 91% and a specificity of 81%. Bowel wall enhancement (ratio of signal intensity of abnormal to normal bowel 1.3:1), and increased mesenteric vascularity using DYN/3D/T1W were useful in

identifying active disease. A layered enhancement pattern after the IV administration

of gadolinium was highly specific for active inflammation.Conclusion: 3.0 T MR imaging, especially the images of DWI and enhancement images using DYN/3D/T1W, is useful in assessing the activity of Crohn’s disease.

C-445 The role of ultrasound in Crohn’s disease: A radiologic review with pathologic correlation L.R. Williams, D. Kasir, S.A. Sukumar; Manchester/UK (lukerobertwilliams@yahoo.co.uk)

Learning Objectives: To review the advantages and limitations of ultrasound in the diagnosis and subsequent management of Crohn’s disease. To illustrate the sonographic appearances, including complications and those findings relevant to disease activity, with examples of histopathological correlation. To discuss the role of ultrasound in the setting of other cross-sectional modalities.Background: Ultrasound is now established as a valuable technique in the diag-nosis and follow-up of patients with Crohn’s disease. With the recent advances in technology, including power Doppler and contrast enhanced ultrasound, we are able to depict activity and complications such as entero-enteric fistulation and ab-scess formation. Ultrasound’s utility in the context of other cross-sectional imaging modalities will be described.Imaging Findings: The sonographic findings of bowel wall thickening will be illustrated with reference to mural echo-pattern and stratification, which will be related to disease activity. Examples of intra-abdominal complications including fistulation, obstruction and abscesses will be demonstrated. The role of dynamic imaging, power Doppler and contrast enhanced ultrasound in determining dis-ease activity and complications will be discussed. The prevalence of transient intussusception in Crohn’s disease will be described with examples. Ultrasound findings will be compared with CT and MR images. Examples of histopathological correlation will be given.

Conclusion: Ultrasound now has clearly defined roles in the diagnosis and follow-up of Crohn’s disease. Familiarity with these appearances is important for an abdominal radiologist.

C-447 Magnetic resonance imaging assessment of small bowel Crohn’s disease activity: Literature review and personal experience R. Girometti, L. Cereser, G. Brondani, A. Furlan, A. Linda, C. Zuiani, M. Bazzocchi; Udine/IT (rgirometti@sirm.org)

Learning Objectives: To review the state-of-the-art role of MRI in assessing the activity of small bowel Crohn’s disease.Background: Since Crohn’s disease is characterized by a chronic and relapsing course, the assessment of inflammatory activity is crucial in planning the patient’s management and in monitoring the effects of therapy. Nevertheless, due to the lack of a universally accepted standard reference, disease activity is currently assessed by a combination of clinical scoring (mainly using Crohn’s disease activity index), biologic indexes, endoscopy, histology, and imaging procedures (small bowel enteroclysis, sonography, or computed tomography). Due to superior soft tissue contrast, dynamic contrast-enhanced information, and the capability of kinematic evaluation of bowel motility, MRI has been advocated as the most powerful imaging tool in diagnosing Crohn’s disease and assessing inflammatory activity, both using enteroclysis or follow-through technique. Increasing evidences suggest a key role for such techniques in addressing patients to proper management. Imaging Findings: As established in literature, more reliable MRI features in assessing inflammatory activity are bowel wall thickening and increased wall en-hancement on gadolinium-enhanced study. Further, MRI findings associated with disease activity, such as the pattern of wall contrast enhancement, are shown in this paper, as well as pitfalls and current limitations in image interpretation. Personal experience using a dedicated MRI score system is illustrated.Conclusion: MRI is highly accurate in assessing Crohn’s disease activity.

C-448 Crohn’s disease integrated imaging: MR-enterography vs CT-enterography P.V. Foti, R. Farina, G. Ganci, M.V. Coronella, D. D’Aniello, G. Politi, G.C. Ettorre; Catania/IT (pietrofoti@hotmail.com)

Purpose: To prospectively evaluate the diagnostic capabilities of Magnetic Resonance Imaging (MRI) and Multidetector Computed Tomography (MDCT) in Crohn’s disease (CD).Methods and Materials: 30 consecutive patients with known or suspected CD under-went MRI and MDCT of the small bowel. MR and CT examinations were performed af-ter oral administration of polyethylene-glycol solution (1 litre and 2 litres, respectively). MRI protocol included T2-weighted SSFSE, FIESTA and Gd-enhanced T1-weighted LAVA sequences. MDCT scans were acquired 60 seconds after i.v. administration of 110-130 ml non ionic iodinated contrast medium. MR and CT scans were evalu-ated by two radiologists blinded to the gold standard represented by conventional enteroclysis, endoscopy and histology findings available in all patients.Results: Disease prevalence was 76.7%. MRI showed sensitivity of 91.3% (95% CI: 79.8%-102.8%), specificity of 85.7% (95% CI: 59.8%-111.6%), accuracy of 90%, predictive positive value (PPV) of 95.5%, predictive negative value (NPV) of 75%. MDCT showed sensitivity of 95.7% (95% CI 87.3%-104%), specificity of 85.7% (95% CI 59.8%-111.6%), accuracy of 93.3%, PPV of 95.7%, NPV of 85.7%. MRI and MDCT evaluated luminal, parietal and extraintestinal findings. MR-fluoroscopy provided functional information about intestinal distension and motility.Conclusion: MR and CT-enterography are complementary non-invasive imaging techniques that enable a complete assessment of CD. Lack of radiation exposure yields MRI as the preferred method for the follow-up of patients with CD. Due to its widespread availability and short examination time, MDCT is the imaging tool of choice in cases of acute clinical presentation or when complications are suspected.

C-449 Mangafodipir trisodium (MnDPDP) enhanced MRI to study excluded duodenum after laparoscopic Roux-en-Y gastric bypass for morbid obesity E. Muraro, P. Marchisio, M. Natrella, D. Furfaro, M. Gallizioli, T. Meloni; Aosta/IT (fiordany@hotmail.com)

Purpose: To study excluded duodenum after laparoscopic Roux-en-Y gastric by-pass (RYGB) for morbid obesity with enhanced MRI, performed after intravenous injection of MnDPDP and biliary excretion of contrast medium.Methods and Materials: 12 patients with RYGB, suffered from repeated upper ab-dominal pain, nausea and hemesis, with no radiological findings of anastomisis leaks or anastomosis stenosis underwent MRI. MR images were obtained at 1.5 T, after intra-

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venous injection of 0.005 mmol/kg of MnDPDP, at a rate of 20 ml/min. We performed fat saturated breath hold three dimensional gradient echo coronal sequences, at patients prone, 30, 60 and 180 minutes after intravenous injection of MnDPDP.Results: In all 12 patients, bile duct enhancement was detected at sequences performed 30 minutes after MnDPDP i.v. injection. Excluded duodenum enhancement (increased signal intensity on gradient echo sequences due to biliary excretion of MnDPDP) was well detected in all patients at sequences performed 180 minutes after MnDPDP injection. In 7 patients, we found extrinsic stenosis of excluded duodenum, caused by abdominal adherences; afterward all were treated with laparoscopic surgery. In one patient, an inter-nal hernia of excluded duodenum was detected and surgically treated. In 2 patients, we demonstrated slow duodenal contrast enhancing, caused by irregular peristalsis, without any evidenced cause. Non surgical treatment was made. In 2 patients, no anatomical or functional abnormalities of excluded duodenum were founded.Conclusion: MnDPDP enhanced MRI could become the method of choice to follow-up the morphology and peristalsis of excluded duodenum after Roux-en-Y gastric bypass for morbid obesity.

C-450 Semi-automated evaluation of small bowel mural attenuation at CT enterography using different temporal windows in patients affected by active Crohn disease G. Lo Re, S. Vitabile, M. Galia, O. Gambino, A. Taibbi, R. Pirrone, M. Midiri; Palermo/IT (giuseppe.lore12@tin.it)

Purpose: The aim of this study is to find the best temporal window of higher small bowel mural enhancement in patients affected by active Crohn disease (CD).Methods and Materials: 35 patients (20 female; 15 male; mean age 39) referred for active CD who underwent CT enterography (CTE) have been selected. In all cases the CTE was performed after oral administration of 2000 mL polyethylene glycol electrolyte balanced solution; before the scan, N-butyl-scopolamine was administered intravenously. All scans were acquired at baseline, 30 and 70 sec. after intravenous administration of 110-130 ml non-ionic iodinated contrast medium (c.m). Further scannings of the most highly enhancing loops (extension maximum 15 centimeters) have been acquired 180 and 300 seconds after intravenous administration of c.m. Acquired data have been elaborated through a medical-driven semi-automatic software tool based on active contour snakes for boundary delineation of the small bowel loops.Results: CTE correctly demonstrated active CD in 34 of 35 patients (97%). The at-tenuation/time curve at different phases demonstrates a higher mural attenuation in active CD, involving small bowel loops at late phase (300 seconds) with a progressive temporal increase in the different phases. The higher mural attenuation of loops is significant when compared with reference stardards (ileoscopy, CDAI). Mural stratifica-tion, another important sign of CD, was best appreciable at hepatic phase.Conclusion: Mural attenuation of small bowel in CD is higher in late phase (300 seconds after intravenous administration of contras) and this appearance is highly correlated to the degree of activity of the CD.

C-451 Comparison of MDCT and MR enteroclysis with selective enterography in the detection of fistulas in Crohn’s disease G. Tóth, L. Tóth, E. Turupoli, Á. Mester; Budapest/HU (totgez@freemail.hu)

Purpose: To compare the utility of MDCT and MR enteroclysis in the detection of fistulas in Crohn’s disease. The gold standard was a selective enterography.Methods and Materials: 52 patients with known or suspected Crohn’s disease under-went 16-MDCT and 1.5 T enterography after injection of methylcellulose solution via nasojejunal catheter and s.c. injection of scopolaminbutylbromide. After native and i.v. contrast enhanced MDCT study, MR acquisition was performed, including axial and coronal T1 native and i.v. contrast FAME, 3D FIESTA, T2 frFSE with fat saturation and T2 frFSE BH sequences. Raw datasets were studied in a dedicated work-station with MPR, MIP and volume rendering algorithms, to demonstrate pathological findings. After 2-5 days, we performed a double contrast selective enterography.Results: Image analysis was performed by two blinded radiologists. MDCT stud-ies detected 6 inter-intestinalis, 3 intestino-sigmoidealis, 2 intestino-vesicalis, 1 intestino-vaginalis and 3 cutan fistulas. MR studies showed another intestino-intestinalis fistula, but did not show jejuno-colic fisula. Selective enterography confirmed all fistulas discovered by CT or MR studies. With selective enterography we discovered another ileo-sigmoid fistula. Our results showed the same accuracy in detection of fistulas with CT and MR enteroclysis.Conclusion: MDCT and MR enteroclysis are two techniques with high specificity and sensitivity value in evaluation of Crohn’s disease. In our series, CT and MR enteroclysis showed good results in detecting fistulas, but we think we need more experience with more patients to analyze a real utility of these two techniques.

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Stomach

C-452 Gastric cancer: Patterns of disease spread via the perigastric ligaments demonstrated by computed tomography S. Peungjesada, P. Bhosale, C. Charnsangavej; Houston, TX/US (silanath.peungjesada@uth.tmc.edu)

Learning Objectives: To demonstrate CT findings of regional spread from gastric cancer.Background: In an embryo, the stomach is suspended in the peritoneal cavity by the dorsal and ventral mesogastrium. Following growth of the peritoneum and clockwise rotation of the stomach, the ventral mesogastrium forms gastrohepatic and hepatodudenal ligaments while dorsal mesogastrium forms the greater omen-tum, gastrocolic and gastrosplenic ligaments. These ligaments consist of 2 layers of peritoneum and cover the blood vessels, lymph vessels, lymph nodes and fat. These structures serve as landmarks for the perigastric ligaments: 1) the left and right gastric vessels for the gastrohepatic ligament, 2) the common hepatic artery, portal vein and bile duct for the hepatoduodenal ligament, 3) the left and right gastroepiploic vessels for the gastrocolic ligament, and 4) the short gastric ves-sels and left gastroepiploic vessels for the gastrosplenic ligament. Disease spread from the stomach occurs along blood vessels, lymphatic vessels,lymph nodes, and nerves within these ligaments.Imaging Findings: The location of primary tumors determines the involvement of different ligaments. Tumors involving lesser curvature have potential spread in gastrohepatic ligament whereas those involving greater curvature will spread in gastrocolic ligament or in the gastrosplenic ligament. Tumors from the gastric fundus and gastroesophageal junction may spread in the gastrohepatic ligament and in gastrosplenic ligament to the splenic hilum.Conclusion: Basic knowledge of anatomy and embryology of the stomach helps radiologists to understand the local spread of the gastric cancer.

C-453 What is your differential diagnosis? Characterization of gastric submucosal tumors J. Kim, J. Lee, H. Park, J. Choi, S. Kim, J. Han, B. Choi; Seoul/KR (poohahe@radiol.snu.ac.kr)

Learning Objectives: The typical and atypical CT features of various gastric submucosal tumors will be demonstrated.Background: There is a variety of gastric submucosal tumors. Radiological findings overlap and have limited roles in the diagnoses of these entities. The purpose of this exhibit is to present a series of challenging cases of various gastric submuco-sal tumors in order to understand the characteristic CT imaging findings of gastric submucosal tumors.Imaging Findings: We will be using the collected imaging data including CT, upper gastrointestinal serieses and endoscopic ultrasonography imaging on 86 patients with pathologically confirmed gastric submucosal tumors.The cases will be presented in a quiz format. Key differential diagnostic points will be discussed in the discussion of each case. The list of cases includes: Gastroin-testinal stromal tumor (GIST), leiomyoma, ectopic pancreas, schwannoma, lipoma, carcinoid tumor, glomus tumor and lymphangioma.Conclusion: Although there are frequent overlaps in the CT appearances of many of these lesions, some have characteristic imaging features. A knowledge of these characteristic CT findings is helpful in the specific diagnoses and may help to avoid unnecessary surgery or invasive procedure. We will also highlight some of the cor-relative pathologic features with gross or histologic specimens.

C-454 Role of endoscopic ultrasound and MDCT for diagnosis of gastric submucosal tumors according to the revised pathologic classification of GIST J. Lim, M.-J. Kim, J.-H. Kim, K. Kim; Seoul/KR (jslim1@yuhs.ac)

Learning Objectives: 1. To explain the readjusted diagnostic strategy of gastric submucosal tumors (SMT) after development of revised classification of GIST on the consensus approach convened by NIH in 2001. 2. To describe the readjusted role of EUS and MDCT 3. To display the advantages of comprehensive interpreta-tion of EUS and MDCT with the pathologic correlation.Background: After development of revised classification of GISTs on the consen-sus approach convened by NIH and ESMO, the role of imagings for diagnosis of gastric SMT should be readjusted. We will discuss the readjusted role of EUS and

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MDCT. EUS procedures have been recognized as clinician’s area. However, the images are easily accessible for radiologists after introduction of PACS. Thus, we will also describe the advantages of comprehensive understandings of EUS and MDCT for diagnosis of gastric SMT.Imaging Findings: 1. Definition of gastric submucosal tumors or subepithelial tumors. 2. Review of readjusted diagnostic strategy after development of revised classification of GIST on the consensus approach convened by NIH in 2001 and ESMO in 2004. 3. Review of role of pretreatment imagings for diagnosis of gastric submucosal tumors. 4. Review of EUS and MDCT findings of gastric submucosal tumors according to the pathologic entities. 5. Discussion about the advantages of each imaging modalities with pathologic correlation.Conclusion: After revision of classification GISTs, the role of imagings for diagnostic strategy should be readjusted. In this clinical situation, comprehensive understand-ings of EUS and MDCT may be help for diagnostic approach of gastric SMT.

C-455 Adjustable laparoscopic gastric banding: The invaluable role of the radiologist A.A. Dawkins, D. Raw, S. Taneja, F. Lee; Sheffield/UK (adrian.dawkins@hotmail.co.uk)

Learning Objectives: After reading this presentation, the reader should: 1) Have an understanding of the normal fluoroscopic appearances post laparoscopic gastric banding. 2) Be familiar with radiological adjustment of laparoscopic gastric banding and potential drawbacks. 3) Be aware of complications encountered and their radiological appearances.Background: Approximately 25% of Britain’s population is obese. Minimally inva-sive bariatric surgery offers a way of tackling morbid obesity. At our institution, we fluoroscopically adjusted approximately three to four “gastric collars” each week for optimal results, allowing a healthy and consistent loss of weight.Procedure Details: Fluoroscopic guidance is used to gain access to a subcutane-ous port, which is linked to the gastric collar via tubing. Contrast is injected into the port and the patient is imaged as a swallow of contrast is performed. The amount of contrast added to or removed from the collar depends partly on the rate at which the neo-stomach appears to empty. Images of complications related to port, con-necting tube and collar are presented.Conclusion: The radiologist plays a pivotal role in the management of patients with laparoscopic gastric bands.

C-456 Detection of tumor recurrence in patients with gastric cancer: Comparison of contrast-enhanced MDCT and 18 F FDG-PET/CT Y. Jeong, J. Kim, J. Kim, S. Shin, H. Kang; Jeollanam-do/KR (yjeong@jnu.ac.kr)

Purpose: To compare diagnostic accuracy between contrast-enhanced MDCT (CECT) and 18 F FDG-PET/CT (PET/CT) for detecting tumor recurrence in patients with gastric cancer.Methods and Materials: Ninety-eight patients, who had undergone surgery for gastric cancer, were included in this study. All images were analyzed in consensus by two radiologists for the presence of recurrence in regard to locoregional recurrence, distant metastasis, liver metastasis, and peritoneal seeding. Each pattern of tumor recurrence was confirmed by pathological proof or by clinical follow-up.Results: A total of 59 lesions were found to have tumor recurrence; locoregional recurrence (n=19), distant metastasis (n=22), liver metastasis (n=8), and peritoneal seeding (n=10). The sensitivity, specificity and accuracy of CECT and PET/CT for overall tumor recurrence were 83%, 97%, 95%, and 76%, 98%, 95%, respectively. For locoregional tumor recurrence, the sensitivity, specificity and accuracy of CECT and PET/CT were 58%, 97%, 90% and 73%, 97%, 93%, respectively. For distant metastasis, the sensitivity, specificity and accuracy of CECT and PET/CT were 90%, 93%, 93% and 77%, 93% 92%, respectively. For liver metastasis, the sensitivity, specificity and accuracy were 100%, 96%, 96% in CECT and all 100% in PET/CT. For peritoneal seeding, the sensitivity, specificity and accuracy were all 100% in CECT and 60%, 99%, 95% in PET/CT.Conclusion: CECT was more sensitive for detecting distant metastasis and perito-neal seeding than PET/CT. PET/CT was more sensitive for detecting locoregional recurrence than CECT. Thus, CECT and PET/CT could be complementary for detecting tumor recurrence in patients with gastric cancer.

C-457 Complications post bariatric procedures: Digital fluoroscopic evaluation V. Morigoni, E. Bozzi, A. Bardine, S. Giusti, M. Anselmino, P. Giusti, C. Bartolozzi; Pisa/IT (valentinamorigoni@tiscali.it)

Purpose: To show the digital fluoroscopic examination, usefulness and accuracy in the follow-up of patients who underwent bariatric proceduresMethods and Materials: From 2001 to 2006, we radiologically reviewed 408 pa-tients submitted to adjustable gastric band, 299 gastric bypass and 107 intragastric balloons. The early examinations were performed 2-5 days after the surgery using water-soluble iodinated contrast agent to highlight gastroenteric canalization, fistulas or contrast media leakages. The late examinations were performed one year after, using barium sulphate.Results: We observed the following early complications: 18 leakages and one communication between the pouch and the gastric remnant, depicted after gastric bypass. The late complications were: 40 migrations of gastric band and 10 migra-tions of intragastric balloon.Conclusion: The rise in bariatric procedures is exponential because of their greater acceptance due to the high incidence of patients affected by pathologic obesity. Although post surgery complication rate are relatively low, they can result in severe disability. Digital radiology, in all cases, enables the detection of early and late post-operative complications, showing the right treatment and so gaining a fundamental role in follow-up of patients who underwent bariatric procedure.

C-458 Development of the water gastric distension method in FDG-PET cancer screening of healthy individuals S. Fujita, K. Kamimura, Y. Umemura, S. Nagamachi, R. Nishii, H. Wakamatsu, S. Tamura, T. Fujimoto; Miyazaki/JP (fujita@fujimoto.or.jp)

Purpose: FDG-PET cancer screening of healthy individuals has been performed widely in Japan, and a high cancer detecting rate of about 2% has been reported. However, the accuracy of gastric cancer detecting rate has been low as the physi-ological accumulation to stomach wall present a pseudo-positive reaction. We have developed methods to improve gastric physiological accumulation in FDG-PET cancer screening by using the water gastric distension method (WGD). Here, we review the utility of these methods. No previous study has assessed the use of WGD in FDG-PET cancer screening.Methods and Materials: 1313 healthy individuals without cancer history under-went PET cancer screening from June 2006 to September 2007. 50 cases that showed focal accumulation to stomach wall performed gastric addition imaging without WGD. All 50 patients took additional 400 ml of water intake for just before a delayed image (WGD method).Results: 3.8% (50 of 1313 cases) showed a focal gastric abnormal accumulation in FDG-PET without WGD. 38.0% of the cases (19 of 50) that showed accumulation after WGD were all Helicobacter pylori infection positive, out of which gastric cancer was detected in 2 cases. There was higher cancer-detecting rate with WGD (10.5%, 2 of 19 cases) when compared with without WGD (4.0%, 2 of 50 cases).Conclusion: FDG-PET cancer screening with WGD was an effective method for suppressing physiological FDG uptake in the stomach and improved cancer detectability.

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C-460 Spontaneous abdominal haemorrhage: Imaging findings of an emergency condition A. Diaz de Otalora Serna, M.S. Carreras Aja, I. Arrieta Artieda, A. Dolado Llorente, A. Urresola, S. Simonetti, L.M. Larrea Bilbao; Bilbao/ES (ainhoadiaz@seram.org)

Learning Objectives: To review the potential causes of nontraumatic hemoperitone-um, providing an overview of imaging findings seen in patients at the emergency room. To emphasize the key CT findings seen in this frequently unexpected diagnosis.Background: Patients presenting with acute abdominal pain often require imaging in the initial diagnostic workup. One of the least suspected underlying causes, by the physician, is spontaneous hemoperitoneum, which requires the radiologist to play an important role not only in the aseveration of abdominal haemorraghe, but also in identifying the underlying cause.Imaging Findings: Although ultrasonography may be useful for the detection of fluid in the abdomen, CT is the modality of choice for the evaluation of an abdominal hemorrhage. Attenuation measurements have a crutial role in differentiating low-attenuation fluid from blood. The site of origin of the bleeding can sometimes be accurately assessed by the presence of a sentinel clot sign arroud the solid viscer, vascular structure or abdominal neoplasm. It is critical to identify the presence of active arterial extravasation as an evidence of active bleeding.Conclusion: This educational exhibit illustrates typical imaging findings of spontane-ous hemoperitoneum. The radiologist should we aware of the possible causes not related to trauma that can be the source of spontaneous bleeding. It is important to recognise the various CT signs to detect the presence of intraperitoneal blood, locate the source of hemorrhage and determine if active extravasation is present in order to establish the indication for an emergent intervention.

C-461 The appreciation of active intra-abdominal haemorrhage at CT T.J.C. Bryant1, S.H. Roy-Choudhury2, D. Thompson1, D.J. Breen1; 1Southampton/UK, 2Birmingham/UK

Learning Objectives: 1. To illustrate the morphology and behaviour of active haemorrhage at CT assessment, particularly with reference to the abdomen and pelvis. 2. To optimise CT technique in the detection of active haemorrhage. 3. To develop an understanding of the significance of active haemorrhage and its ap-propriate triage to interventional radiology or surgery.Background: The increasing spatial and temporal resolution of multidetector CT systems combined with optimal intravenous contrast enhancement techniques have lead to a better appreciation of active haemorrhage at CT. The rate of bleeding, organ of origin, and the space into which it occurs affect the imaging characteristics. This exhibit aims to illustrate the behaviour of active haemorrhage and thereby improve recognition of active bleeding at CT.Imaging Findings: IV contrast administration at rates of 3.5-5 ml/second helps to demonstrate bleeding in the late arterial phase. However, due to the variable rate of bleeding, the portal venous phase remains the most important phase of acquisition. In equivocal cases our experience has shown that early, (90-150 second) repeat studies are the most useful at confirming slower bleeding. On delayed studies, (4-5 minutes) contrast extravasation is often poorly appreciated. A collection of cases to support this will be presented, including haemorrhage from solid organ and GI tract.Conclusion: The CT appreciation of active haemorrhage requires optimal contrast enhancement. More important, however, is an understanding of how variable sites of bleeding behave according to the medium and space into which that haemor-rhage is occurring.

C-462 Various cystic lesions of gastrointestinal tract: Radiologic findings with pathologic correlation J. Lee, C. Park, K. Kim, C. Lee, J. Choi, S. Lee, B. Shin; Seoul/KR

Learning Objectives: 1. To review the disease categories of various gastrointestinal (GI) cystic lesions. 2. To describe the multimodality imaging findings of cystic lesions of the GI tract. 3. To correlate the radiologic findings with findings on pathology.Background: Various cystic lesions of the GI tract are seen in pathologic findings. Some of the lesions are easily diagnosed because of characteristic radiologic features and anatomic locations, but others may be a challenge to differential di-

agnosis. In this exhibition, we review the various cystic lesions of the GI tract, from the stomach to the rectum, and illustrate the radiologic features of multimodality imaging. We also correlate the radiologic features with the pathologic findings.Imaging Findings: We will illustrate the following: 1. Congenital lesions - broncho-genic cyst, duplication cyst, ectopic pancreas. 2. Cystic neoplasms - mucinous cyst-adenoma of the appendix and colon, cystic lymphangioma of the colon, mucinous carcinoma of the rectum. 3. Cystic degeneration of solid tumors - GIST, neurogenic tumor, adenocarcinoma. 4. Miscellaneous - gastritis cystica profunda, hematoma, etc. The imaging features of these cystic lesions of the GI tract will be presented on different types of imaging modalities, including ultrasonography, multi-detector CT, and MR imaging with pathologic correlation.Conclusion: Knowledge of the various disease categories and imaging charac-teristics of cystic lesions of the GI tract can help ensure correct diagnosis and proper management.

C-463 Radiographic, MRI and MDCT anatomy of abdominal viscera after major gastrointestinal surgery M. Anzidei, A. Napoli, B. Cavallo Marincola, C. Zini, F. Francesco, P. Di Paolo, C. Catalano, R. Passariello; Rome/IT (mikilgenio@hotmail.com)

Learning Objectives: To describe the most frequent procedures performed in gastrointestinal (GI) surgery. To present the normal post-operative aspect of abdominal viscera on radiographic, MRI and MDCT images.To illustrate common signs of complications.Background: Frequent procedures performed in GI surgery involve the esophagus, stomach, small bowel, colon, and rectum. Post-operative controls are usually per-formed with conventional contrast radiographic studies. However, MRI and MDCT are emerging as excellent diagnostic tools in complicated cases.Procedure Details: The most common approaches in GI surgery are described, as well as indications, advantages and possible limitations of radiographic techniques, MRI and MDCT for post-operative imaging of each segment. Complicated and uncomplicated scenarios of esophagectomy, gastrectomy, Whipple resection, total and partial colectomy, total mesorectal excision and Miles amputation are discussed. Selected cases with post-surgical hemorrage, free peritoneal collections of fluid and air, abscesses, surgical drainage, gossypiboma, suture dehiscence, fistulas, tumor recurrence and fibrosis of hollow viscera are presented.Conclusion: Knowledge of the most frequent surgical procedures performed in GI tract and of the various normal and abnormal aspects of post-operative anatomy is mandatory in order to perform proper follow-up.

C-464 Imaging of tropical diseases A. Manzella, P. Borba-Filho, K. Batista, L. Santana, F. Farias, J. Santos-Filho, C. Carneiro, J. Kaercher, C. Ribeiro, C. Fontan; Recife/BR (adonismanzella@yahoo.com.br)

Learning Objectives: 1) To present a comprehensive review of various tropi-cal diseases. 2) To illustrate the imaging findings using a range of radiological modalities.Background: At least 1 billion people, or 1 person in 6, suffer from one or more tropical diseases (TD). Often, those populations most affected are also the poorest and most vulnerable and are found mainly in tropical and subtropical areas of the world. Some TD affect individuals throughout their lives, causing a high degree of morbidity and physical disability. Others are acute infections, with transient, severe and sometimes fatal outcomes. The purpose of this review is to discuss and illustrate the imaging findings of some of these TD.Imaging Findings: The authors discuss the epidemiology, pathophysiology, life cycle, clinical manifestations, complications and imaging features of some TD. Included in this essay are cysticercosis, hydatidosis, lymphatic filariasis, schistoso-miasis mansoni, ascariasis, trypanosomiasis, clonorchiasis, dengue, tuberculosis and amebiasis. The imaging features are illustrated using a multimodality approach (plain films, barium studies, ultrasound, angiography, CT and MRI).Conclusion: With increased immigration and frequent traveling, some patients with TD may be encountered in non-endemic areas and the diagnosis may be delayed or difficult. Every radiologist should be aware of the typical imaging findings in order to consider these entities the differential diagnosis.

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C-465 MR entero-colonography: A role beyond Crohn’s disease? I. Aguirre1, M. Aduna2, J. Larena2, A. Merino1; 1Las Arenas (Getxo)/ES, 2Galdakao/ES (iratxeaguirre@seram.org)

Learning Objectives: To describe the features of MR entero-colonography in several intestinal entities different from Crohn’s disease and to suggest some indications of the technique.Background: MR entero-colononography is an emerging diagnostic tool, which is a major indication in the diagnostic workup of patients with Crohn’s disease. However, a wide spectrum of entities can be assessed including developmental malformations, hereditary diseases, inflammatory/infectious pathologies, neoplastic disease, vascular disorders and iatrogenic conditions. Some MR findings in these entities are not specific, but familiarity with these pathologies is necessary to ensure an accurate diagnosis.Procedure Details: A total of 650 patients who underwent MR entero-colonography between 2003 and 2007 were reviewed selecting those with confirmed small bowel or colonic pathologies not associated with Crohn’s disease. A bowel cleansing procedure was used prior to imaging and a mixture of fibroaguar, sorbitol, barium sulphate and 1200 ml of water was given orally 40 minutes before examination. Colon distension was achieved with a 2000 ml water enema (10 ml of gadolinium was added if fistula was suspected). MR protocol included True-Fisp, T2W HASTE sequences and VIBE before and after gadolinium i.v. To reduce bowel peristalsis, an abdominal-specific antispasmodic agent was i.v. administered. We illustrate a spectrum of pathologies (congenital, inflammatory, infectious, neoplastic, isquemic and iatrogenic) and show the accuracy of the technique especially in the setting of failed colonoscopy for tumour evaluation and depiction of enteric fistulas.Conclusion: MR entero-colonography is a useful technique depicting entero-colonic findings, which may help in the diagnosis of several intestinal disorders.

C-466 Fever and pain in the left iliac fossa: Not always diverticulitis S. Roche, M. Escobar, M. Romera, R. Vidal, P. Veciana; Barcelona/ES (manel.escobar@gmail.com)

Learning Objectives: 1. To show the normal anatomy of the left iliac fossa. 2. To describe pathologies that may present with fever and pain in the left iliac fossa. 3. To emphasize the role of multislice CT in the differential diagnosis.Background: In the adult, fever and pain in the left iliac fossa brings to mind di-verticulitis as the first diagnosis. However, there are other pathologies, which may present with similar symptoms and is the mission of the radiologist to diagnose them. In this exhibit, we wish to present the common and uncommon entities, which may simulate diverticulitis clinically, emphasizing the contribution of multislice CT in the final diagnosis.Imaging Findings: The left iliac fossa is a crossroad in which the GI tract (sigmoid colon), the GU tract (left ureter and left ovary in the female) and the iliac vessels coincide. Aside from diverticulis, processes of the GI tract that may affect this area are perforated sigmoid neoplasias, acute appendicitis, intestinal malrotation with left appendicitis and Meckel´s diverticulum. Processes of the GU tract include unusual ureteral lithiasis, tubo-ovarian abscesses, torsioned dermoid tumours and endometriosis. Another cause to be considered is perforation by foreign body, either on ingestion (toothpick, fishbone) or on rectal introduction (pen).Conclusion: Awareness of the different entities that may simulate diverticulitis will lead to an adequate use of multislice CT, resulting in an accurate diagnosis in the great majority of cases.

C-467 MR imaging of perianal fistulas: A review and pictorial essay N. Ribeiro1, F. Reis Costa1, A.C. Silva2, J. Venâncio2, M.C. Tavares2, C.A. Ribeiro2; 1Viseu/PT, 2Matosinhos/PT (Nuno_pinto@portugalmail.pt)

Learning Objectives: The aim of this study is to review the perianal region anatomy with MR imaging correlation, discuss the aetiology of perianal fistulas, describe the preoperative evaluation and classification of perianal fistulas and demonstrate the MR imaging findings of perianal fistulas and abscesses.Background: Perianal fistulization is a relatively common and important condition that causes substantial morbidity, with a prevalence of about 1:10, 000 persons. Accurate recognition and classification of the perianal fistulas and their associated findings is of great value so that complications, such as abscess formation and recurrence, can be minimized.Imaging Findings: Normal perianal anatomy in MR imaging is first depicted with a brief discussion on the MR pulse sequences used for anatomic and fistula assessment. The fistulous tracks are then classified and demonstrated with MRI,

according to their relations with the anal sphincter complex and pelvic floor, as inter-sphincteric, trans-sphincteric, supra-sphincteric and extra-sphincteric. MR imaging can easily demonstrate the existence of secondary tracks and abscesses. Special emphasis is given to this issue, because missed extensions are the com-monest cause of recurrence.Conclusion: MRI is now a generally available technique that can clearly demon-strate the anatomy and pathological findings of the perianal region.It can demonstrate the fistulous tracks and ramifications, and its relations with the anatomic structures such as the sphincter complex, the ischioanal and ischiorectal fossae and the levator plate. This is of major relevance because it can dictate the best surgical management, and therefore, the best outcome.

C-468 Gastrointestinal surgical procedures: A primer for the radiologist S. Ramamurthy, S.H. Rashid, V. Rachapalli, N. Goyal, A. Yong; Cardiff/UK (sidi.rashid@yahoo.co.uk)

Learning Objectives: Knowledge of surgical techniques and major complications is extremely important for performing imaging study and interpretation correctly. The significantly altered post-operative anatomy can be problematic in interpreta-tion of the studies performed. The purpose of this poster is to provide an overview of the commonly performed gastro-intestinal surgical procedures. We have also illustrated a few commonly occurring post-operative complications and their imag-ing findings.Background: Diagnostic imaging plays a vital role in the study of the post-op-erative gastro-intestinal tract. The surgical procedure could either be an excision, reconstruction or a combination of both. Plain radiography carried out with or without contrast, along with the more advanced imaging techniques such as com-puted tomography and magnetic resonance imaging demonstrate both the altered anatomy and complications.Procedure Details: The poster is broadly divided into procedures on the foregut, midgut and hindgut. An overview of the indications for each of the procedures along with detailed illustration of the actual procedure is provided. We also pres-ent a brief overview of multimodal imaging findings of common operations and their complications.Conclusion: Understanding of common gastro-intestinal surgical procedures and post-operative anatomy is indispensable to the radiologist. Knowledge of the com-mon complications following these procedures will be very useful while interpreting post-operative diagnostic images.

C-469 Appendicitis ruled out: Alternate causes of right lower quadrant pain in emergency department patients S. White; Boston, MA/US

Learning Objectives: To illustrate the spectrum of pathologies encountered in emergently requested CT scans of the abdomen and pelvis (CT abd/pel), performed to “rule out appendicitis”.Background: Right lower quadrant (RLQ) pain is a frequent cause of patient visits to the Emergency Department (ED). Appendicitis is a highly common and treatable cause of RLQ pain, and as such a frequent indication for emergent CT abd/pel is to “rule out appendicitis” or “R/O appy”. There is a spectrum of non-appendicitis pathologies which may mimic the clinical findings of appendicitis, including patholo-gies of the abdominal wall, large and small bowel, mesentery, omentum, and epiploic appendages, pelvic viscera, genitourinary system and vasculature. Examples of alternate (non-appendicitis) causes of RLQ pain will be presented.Imaging Findings: CT abd/pel scans performed in ED pateints with an indication of “r/o appy” or “RLQ pain” were collected over a 16 month period. Non-appendicitis pathologies included cases of: abdominal wall hematoma, omental infarct, epiploic appendagitis, infectious/inflammatory colitis and ileitis, right colon diverticulitis, ileal perforation, duodenal perforation, duodenal diverticulitis, closed loop bowel obstruction, superior mesenteric venous thrombosis, right pyelonephritis, right urolithiasis, right hydrosalpinx, hemorrhagic ovarian cysts, and others. Selected images from such cases will be provided.Conclusion: CT abd/pel is heavily utilized in the emergency department to evaluate patients with RLQ pain. Familiarity with the wide spectrum of pathologies encoun-tered in those patients without appendicitis is essential.

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C-470 Signs of pneumoperitoneum on supine abdominal film: Every lucency in the abdomen must be interpreted A. Pinto, M. Scaglione, A. Sparano, C. Muzj, S. Nicotra, F. Pinto, L. Romano; Naples/IT (antopin1968@libero.it)

Learning Objectives: To illustrate the spectrum of signs of pneumoperitoneum on supine abdominal film. To outline the advantages and limits of the supine free air series. To correlate plain film findings of pneumoperitoneum with the site of perforation at surgery.Background: In patients with clinically suspected gastrointestinal perforation, plain abdominal film is the initial diagnostic method of choice. The radiographic finding of pneumoperitoneum signifies a surgical emergency, because it most commonly, although not always, results from perforation of the gastrointestinal tract. Because many patients with gastrointestinal perforation are unable to cooperate for satis-factory radiography with a horizontal beam, it is incumbent upon the radiologist to recognize signs of pneumoperitoneum on the supine film.Imaging Findings: Plain abdominal films were obtained in supine position. MDCT examination was performed in subtle cases to confirm the presence of pneumo-peritoneum or of pneumoretroperitoneum. Plain abdominal film signs of perforation include: the Rigler sign, air in the Morison pouch, subhepatic gas, the hyperlucent liver sign, gas in the lesser sac, visibility of the inferior heart border, the cupola sign, the falciform ligament sign, air in the intrahepatic fissure, the inverted V sign, the urachus sign, the football sign, the telltale triangle sign, the diaphragm muscle slip sign and scrotal air.Conclusion: Proper interpretation of the various signs of pneumoperitoneum on su-pine abdominal films should lead to a more accurate diagnosis of this condition.

C-471 Drug smuggling by body packing: How to avoid error in diagnosis A. Pinto, M. Scaglione, M. Scuderi, S. Merola, M. Pepe, C. Stavolo, L. Romano; Naples/IT (antopin1968@libero.it)

Learning Objectives: To describe the different drugs smuggled and how drugs are hidden in the body. To illustrate the radiological methods to investigate body packers on a series of 18 patients. To discuss the medico-legal issues related the radiological evaluation of body packers.Background: Drug smuggling via body orifices, also known as body packing, has increased in frequency and sophistication in both the United States and Europe. Most of these cases go undetected, but a growing number have resulted in medical emergencies that present in the emergency department. The aim of this exhibit is to make radiologists aware about how drug packets may look with different radiological tools and which complications have to be able to recognize.Procedure Details: Abdominal plain films were obtained in erect position. The following signs on the abdominal radiograph were searched for the presence of body packing: multiple radiodense foreign bodies, a “rosette-like finding” formed by air trapped in the knot where a condom is tied, and a “double-condom” sign, in which air trapped between layers of latex makes them more visible. Abdominal sonography and abdominal computed tomography examination were performed in equivocal cases or in presence of complications.Conclusion: Patients suspected of being body packers require radiographic evaluation. The radiologist has a critical role for the identification of a person as a body packer and for the recognition of abdominal complications induced by the drug-filled ingested packets.

C-472 Inherited gastrointestinal polyposis syndromes: Extraintestinal manifestations M.D.G.A. Certo1, L. Lopes2; 1Santo Tirso/PT, 2Viana do Castelo/PT (manuelacerto@sapo.pt)

Learning Objectives: To describe and illustrate the extraintestinal manifestations in patients with inherited gastrointestinal polyposis syndromes.Background: Gastrointestinal (GI) polyposis refers to the presence of numerous polypoid lesions throughout the GI tract. The most common adenomatous polyposis syndrome is the familial adenomatous polyposis (FAP). Variants of classic FAP include Gardner’s syndrome, attenuated adenomatous polyposis coli, and Turcot’s syndrome. The Peutz-Jehers syndrome, juvenile polyposis, and Cowden’s disease are characterized by multiple hamartomatous polyps. All these syndromes are inherited and are associated with an increased colon cancer risk. Extraintestinal abnormalities are not so uncommon. Imaging is important to evaluate and screen the other organs, besides the GI tract.Imaging Findings: FAP extraintestinal abnormalities include mandibular os-

teomas and dental abnormalities. Osteomas of the mandible, skull, and long bones, congenital hypertrophy of the retinal pigment epithelium, desmoid tumors, epidermoid cysts, fibromas, lipomas, thyroid and adrenal tumors can be found in patients with Gardner’s syndrome. Turcot’s variant is associated with medul-loblastoma, glioblastoma multiforme and congenital hypertrophy of the retinal pigment epithelium. FAP gene carriers are also at risk for pancreatic, thyroid and liver cancers. Ovarian sex cord tumors, sertoli tumors of testis, airway and urinary polyps, pancreatic and breast cancer may be seen in patients with Peutz-Jeghers syndrome. Benign and malignant, breast or thyroid diseases can appear in patients with Cowden’s disease.Conclusion: Extraintestinal abnormalities in patients with inherited gastrointestinal polyposis syndromes are numerous and quite diverse. Imaging plays an important role in screening the different organs at risk for cancer.

C-473 CT findings of acute mesenteric ischemia: A pictorial review M. Pimentel-Martins, G. Gerediaga, C. Albuquerque, C. Santiago, I. Beirão; Viseu/PT (marianapmartins@hotmail.com)

Learning Objectives: To illustrate the broad spectrum of CT findings of acute mesenteric ischemia (AMI).Background: AMI is a frequent condition that ranges from mild bowel ischemia to a more dangerous and potentially life-threatening transmural bowel wall necrosis. It may be caused by many conditions and manifests with a broad range of clinical, laboratory, and radiologic findings. CT has been used in patients with suspected AMI, as it helps in the detection of ischemic changes in the affected bowel loops and mesentery and can exclude other differential diagnosis of acute abdominal conditions. Furthermore, the cause of the ischemia can sometimes be detected by allowing evaluation of the mesenteric vasculature, especially with multi-detector row CT with 3D reformatting. There are numerous CT findings in AMI, with bowel wall thickening being the most frequent. Mesenteric arterial or venous occlusion, pneumatosis and portomesenteric venous gas have been reported as less com-mon, but more specific, findings.Imaging Findings: The authors retrospectively reviewed 88 cases of AMI diag-nosed in their hospital in a 2 year period. The cases that will be presented are the ones with the most illustrative CT findings including occlusion of the superior mesenteric artery, portomesenteric venous gas, pneumatosis and absence of bowel wall enhancement.Conclusion: CT is presently the key imaging modality for the diagnosis of AMI although this condition may simulate many other inflammatory or neoplastic dis-eases. Therefore, because of the variable and non-specific clinical and radiologic-pathologic manifestations, a strongly clinical-radiologic approach must be pursued in the detection of AMI.

C-474 Non-tumorous perianal lesions: Evaluation with various imaging modalities S. Rha, S. Oh, S. Jung, J. Byun, Y. Lee; Seoul/KR (hiohsn@catholic.ac.kr)

Learning Objectives: To illustrate the normal anatomy of the anal canal on various imaging modalities. To demonstrate the imaging findings of various kinds of non-tumorous perianal lesions. To describe the merits and demerits of various imaging modalities for perianal lesions.Background: The anatomy of the anal canal is complex and various disease entities, such as developmental disorders, functional disorders, and infectious or inflammatory disorders, can involve the perianal region. The diagnosis of perianal lesions relies on a multi-modality approach including ultrasonography, defecography, CT, and MRI, depending on the disease categories. It is helpful for the radiologist to know proper imaging modalities, the merits and demerits of respective imaging modalities, and their imaging features for the various perianal lesions.Imaging Findings: Developmental cysts of the perianal region include epider-moid cysts, dermoid cysts, and enteric cysts (tailgut cysts and rectal duplication). These lesions appear as perianal cystic lesions. The signal intensity on MRI may be suggestive of the internal contents of the cysts. Functional disorders including constipation, fecal incontinence, spastic pelvic floor syndrome, and pelvic organ prolapse can be evaluated using real-time ultrasound, defecography, and MRI. Imaging of the perianal abscess and fistula plays a role in the demonstration of fistulous tract and extent of disease.Conclusion: The major teaching points of this exhibit are: 1) Ultrasound and MRI are the most useful modalities for the evaluation of anatomical structure of the perianal region. 2) Familiarity with imaging findings of various perianal lesions will facilitate proper selection of imaging modalities and accurate diagnosis.

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C-475 CT criteria for evaluation of primitive and metastatic GIST lesions before and in the early post-treatment period with imatinib A. Bulzacchi, I. Lionetti, M. Nardin, G. Pintacuda, D. Pastorelli, U. Basso, F. Farinati, P. Muzzio; Padua/IT (ivana.lionetti@libero.it)

Learning Objectives: The aim of this exhibit was to describe the volumetric, morphological and densitometric changes of CT images in primitive and metastatic GIST lesions before and in the early post-treatment period with Imatinib.Background: We reviewed imaging data of 15 patients with GIST; the diagnosis was made with CT- or US-guided fine needle cytological aspiration (FNAC), sometimes associated with core biopsy. We compared the imaging findings of the primitive and metastatic GIST lesions before and up to 1 month after Imatinib treatment.Imaging Findings: With contrast-enhanced CT, the primitive and metastatic GIST localizations before Imatinib treatment appeared as exophitic, large and hypervascu-lar masses with inhomogeneous density, irregular borders and infiltration to adjacent organs. In the early post-treatment phase, instead, lesions became typically more homogeneous and hypoattenuating, with significant reduction of vascularisation, disappearance of enhanced nodules and sometimes tumour enlargement. This last characteristic could be due to mixoid degeneration, haemorrhage or oedema, which are all possible consequences of Imatinib treatment. Hypoattenuation, on the other hand, was due to cystic degeneration or necrosis, both of which indicate therapy response.Conclusion: According to literature, our study showed that the association in CT images of hypoattenuation and tumour enlargement is an indicator of a good therapy response. For this reason, standardized criteria (SWOG, RECIST), which are based on the dimensional reduction of lesions, cannot be applied to patients affected by GIST. We hope in the near future that this study will contribute to a new criteria for tumoral response to therapy, more specific for GIST.

C-476 Fat stranding on emergency abdominal CT: Where to look at M. Montes Fernandez, B. Nieto Baltar, N. Arevalo Galeano, M. Ciudad Fernandez, Y. Martinez Alvarez, L. Grana Lopez, E. Vano Galvan; Madrid/ES (nietba@yahoo.es)

Learning Objectives: To be aware of the importance of fat stranding in locating the abdominal urgent pathology. To be familiar with the differential diagnoses depend-ing of the fat stranding location. To differentiate the benign entities that resemble life-threatening diseases.Background: CT plays a crucial role in differentiating the underlying causes of the symptoms in acute abdomen. Fat stranding is a CT sign that helps in the evaluation of patients with acute abdominal pain in emergency radiology. It is not pathognomonic, though it warns us where to look at. Fat stranding may arise from many causes that should be considered in the differential diagnosis. Acute condi-tions that cause fat stranding include appendicitis, ischemia or perforation of the bowel, cholecystitis, trauma and surgery.Imaging Findings: We have made a pictorial review showing and describing the CT imaging features of the most common abdominal urgent pathology. We try to demonstrate how fat stranding on abdominal CT can help us to identify the crucial point of the acute abdominal at first sight. Once localized, we describe the specific imaging finding that will lead us to a final diagnosis. Correct non-invasive diagnosis is important because treatment approaches for these conditions range from monitoring to surgery. We show some key facts to help us to differentiate both groups.Conclusion: Fat stranding is a useful sign to localize the underlying pathology in acute abdomen. Knowledge of CT signs accompanying it helps us to reach a final diagnosis and therefore a more accurate clinical decision.

C-477 Radiation exposure in patients with inflammatory bowel disease. Current status and future directions K. O’Regan, A. Desmond, C. Ni Churrain, S. McWilliams, S. McSweeney, F. Shanahan, M.M. Maher; Cork/IE (oregankevin@yahoo.co.uk)

Learning Objectives: a) To discuss current available data from our institution re-garding radiation exposure to patients with inflammatory bowel disease as a result of computed tomography. b) To discuss rationale for radiation dose optimisation in these patients c) To discuss approaches to radiation dose reduction in these patients including definition of indications for CT, protocol modification, use of emerging CT technology and use of alternative imaging modalities.Background: Inflammatory bowel disease (IBD) is a group of diseases charac-terised by a chronic relapsing course in a very young population, in which CT is increasingly being used for diagnosis and surveillance. Radiation dose in these young patients is an increasing concern.

Imaging Findings: The place of CT versus other imaging modalities in imaging IBD will be evaluated. Role of emerging technology for radiation dose optimisation will be discussed.Conclusion: Recently acquired data support the view that issue of radiation dose associated with CT scanning in patients with IBD should be a cause for concern.

C-478 Unusual hernias: An uncommon cause of acute abdomen B. Gutierrez, A. Franco, O. Benítez, A. Arjonilla, M. Tomás; Madrid/ES (begogutisanjose@yahoo.es)

Learning Objectives: To ilustrate the radiologic CT findings of different types of uncommon hernias (external, internal and diaphragmatic) that may constitute an unusual cause of acute abdomen.Background: Unusual abdominal hernia as a cause of acute abdomen may be a difficult diagnosis to make. This may be because they are not clinically suspected and also because of a lack of familiarity with their radiologic appearances. In the present day, CTMD provides great multiplanar reconstructions that allow a confident diagnosis to be made if the usual and unusual locations are known and bowel loops are exhaustively followed. One has to keep them in mind whenever a CT is performed for acute abdomen.Procedure Details: Ten cases of acute abdomen due to uncommon hernias were diagnosed at our institution between Octuber 2005 and March 2007. We present three internal hernias (one transmesenteric, one pericecal and one mesocolic), six cases of external hernias (one Amyand, one spiegel, two inguinal and two obturator), and one case of post-traumatic diaphragmatic hernia. All diagnoses were surgically confirmed except one in which surgery was desisted because of patient´s comorbility.Conclusion: We describe the location and radiologic appearance of different types of unusual hernias as an uncommon cause of acute abdomen.

C-479 Acute gastrointestinal bleeding: Detection with arterial and portal venous phase imaging using MDCT Y. Jeong, W. Yoon, H. Kang; Jeollanam-do/KR (yjeong@jnu.ac.kr)

Learning Objectives: To compare the diagnostic accuracies of arterial and portal venous phase MDCT scan for detection of acute gastrointestinal (GI) bleeding.Background: A total of 62 consecutive patients with suspicious acute GI bleeding underwent MDCT scan with arterial and portal venous phase before angiography as reference standard. Extravasated contrast medium within bowel lumen was consid-ered to be GI bleeding. Two abdominal radiologists (reader A and B) reviewed the arterial phase with nonenhanced image (session I), and arterial with portal venous phases and nonenhanced images (session II). The presence of contrast medium extravasation in each anatomic location was recorded. The diagnostic capability was determined by calculating the area under the ROC curve (Az) for each reader. Interobserver agreement (k value) was also assessed.Procedure Details: For detection of acute GI bleeding, Az values were 0.769 for reader A and 0.821 for reader B. Interobserver agreement between reader A and B was 0.79.Conclusion: Combined interpretation of arterial with portal venous phases and nonenhanced MDCT images may be of useful diagnostic accuracy in the detec-tion of acute GI bleeding. Combined interpretation of arterial with portal venous phases and nonenhanced image provides good interobserver agreement in the detection of acute GI bleeding.

C-480 Inferior mesenteric vein, normal anatomy, variations and pathological implications: Imaging with 64-row multislice computed tomography P. Arguis, M. Pages, S. Rodriguez, M. Sanchez, C. Ayuso; Barcelona/ES (32369pag@comb.es)

Learning Objectives: To provide a pictorial review of CT imaging of the inferior mesenteric vein (IMV).Background: Superior mesenteric vein, splenic vein and portal vein are the main drainage system of the abdomen and have been well studied in abdominal CT scans. The multislice computed tomography (MSCT)technology allows better identification of smaller veins such as the IMV, which drains venous outflow from the intestine (distal transverse colon to proximal rectum) to the portal system. It joins the splenic vein. However, there are variations to this pattern and there is a spectrum of clinical entities, which may involve the IMV. The conditions include septic thrombophlebitis, thrombosis, diverticulitis, Crohn’s disease, malignancies, bowel ischemia and portal hypertension.

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Procedure Details: Imaging findings include those of patients with normal IMV and with pathological conditions involving the vein. All exams were obtained with a 64-row MSCT using a portal venous phase with axial and coronal reconstruction.Conclusion: Multidetector CT technology provides accurate IMV visualisation, useful to understand some pathological conditions.

C-481 Gossypibomas: Spectrum of imaging findings A. Manzella, P. Borba-Filho, J. Kaercher, F. Farias, C. Carneiro, D. Sales, L. Santana, A. Rodrigues; Recife/BR (adonismanzella@yahoo.com.br)

Learning Objectives: 1. To discuss the clinical manifestations related to gossypi-bomas. 2. To illustrate the typical imaging features using a multimodality approach. 3. To provide surgical correlation in some cases.Background: Textiloma and gossypiboma are non-medical terms used to describe a mass of cotton matrix that is left behind in a body cavity during an operation. The term gossypiboma is derived from the Latin word gossypium, meaning cotton, and Kiswahili word boma, meaning place of concealment. This is an uncommon surgical complication with an estimated incidence of 1/1500. Gossypibomas are most frequently discovered in the abdomen. However, their occurrences in the thorax, extremity, central nervous system, and breast have also been reported. Such foreign bodies can often mimic tumors or abscesses clinically or radiologi-cally. Although these masses and their associated complications may occur, they are rarely reported due to medico-legal implications.Imaging Findings: Because the symptoms of gossypiboma usually are non-specific and may appear years after surgery, awareness of a gossypiboma usually comes from imaging studies. The purpose of this essay is to discuss and illustrate the im-aging findings related to gossypibomas in different locations using a multimodality approach with surgical correlation in some cases.Conclusion: The manifestations and complications of gossypibomas are so variable that diagnosis is difficult and patient morbidity is significant. Therefore, radiologists should be aware of their imaging features.

C-482 Trapped on the “whirl”: Diagnostic sign on emergency CT V.M. Suárez-Vega, M. Martí, E. Alonso, V. Pérez-Dueñas, C. Palacios; Madrid/ES (proksua1@hotmail.com)

Learning Objectives: To describe the so-called “whirl sign” features on emergency CT. When and where should we look for this sign? To distinguish the differences between the “whirl sign”, the “superior mesenteric vein rotation” sign, and the ultrasonographic “whirlpool sign”, the latter considered to be a sign of malrotation. To illustrate the spectrum of entities that may show this sign. To depict associated findings which support the diagnosis.Background: The “whirl sign” is an uncommon finding on emergency CT. However, it is easy to overlook if not kept in mind. Its recognition is of capital importance, being most of its causes potentially lethal. Surgical treatment is also mandatory when signs of complication are found. We retrospectively reviewed the imaging findings of patients with the “whirl sign” from our database of emergency pathology. Related entities and associated findings were analyzed.Imaging Findings: The “whirl sign” was found associated to midgut, cecal and sigmoid volvulus, post-surgical mesenteric window, internal hernia and malrota-tion. Attention was also focused on signs suggesting complication (circumferential wall thickening, pneumatosis intestinalis, pneumoperitoneum, mesenteric fat stranding, free intraperitoneal fluid, mesenteric haziness). Diagnostic difficulties are emphasized.Conclusion: Radiologists must be able to recognize the “whirl sign” and seek as-sociated findings which strongly support the diagnosis of a spectrum of entities, some of them lethal if no treatment is established.

C-483 MRI in perianal Crohn’s disease J.P.A.F. Caldeira, I.N. Duarte; Lisbon/PT (joaopedro117@gmail.com)

Learning Objectives: To illustrate the spectrum of MRI findings in perianal inflam-matory complications in Crohn’s disease. To outline the advantages and limitations of the technique as well as its indications.Background: Crohn’s disease is a chronic, transmural inflammatory disorder that can affect any part of the gastrointestinal tract. The risk of inflammatory perianal disease is estimated over one-third of the patients during the course of their dis-ease. Between January 2000 and March 2007, patients followed in our institute with clinical suspicion of perianal disease were submitted to a pre-treatment MRI which has shown essential on the location, extent and severity of the inflammatory

process, becoming crucial in choosing the proper therapy, guiding to a surgical versus medical approach.Procedure Details: Examples of our findings are presented according to Parks classification of fistula in ano, using an MRI protocol composed of axial-T1, axial and coronal-T2 and SPIR-T2 sequences on a 1.0-T scanner (Philips Gyroscan NT10) using an external phased-array coil. This work shows that the information given by T2-sequences is important to anatomic detail assessment and the SPIR-T2 images to depict the active inflammatory disease, even when is doubtful in T2. Coronal plans are essential in differentiating infra and supra-levator disease, which has direct therapeutic implications.Conclusion: It is now recognized that pre-treatment imaging, mainly MRI, can be used as a powerful tool in the recognition of findings in inflammatory perianal disease and add information missed in clinical evaluation, thus providing an essential role in the guidance of the adequate therapeutic approach.

C-484 Gastrointestinal tract perforation: CT findings - what to look for? I. Arrieta Artieda, J. Mendiola Arza, M.S. Carreras Aja, M. Lazaro Serrano, A. Dolado Llorente, I. Terreros Bejo, L. Larrea Bilbao; Barakaldo, Vizcaya/ES (magdalenasofia.carrerasaja@osakidetza.net)

Learning Objectives: To review the computed tomography (CT) appearance of gastrointestinal tract (GI) perforation. To emphasize the characteristic CT findings that indicate the presence, site and cause of perforation.Background: GI perforation is an emergent condition that usually requires prompt surgery. CT is an easy and very sensitive imaging modality in diagnosing GI perfora-tion. The preoperative knowledge of site and cause of perforation is beneficial for surgeons to perform surgical planning (laparoscopic procedure or open surgery).Procedure Details: Free intraperitoneal air in association with acute abdominal pain is a major finding in the diagnosis of presence of GI perforation. The site of perforation can be assessed by findings of: (a) focal bowel-wall defect, (b) the site of luminal contrast medium leakage, (c) segmental GI wall thickening with or without an associated phlegmon, inflammatory mass or abscess, and (d) amount and location of extraluminal air. Tiny free air bubbles in close proximity to the bowel wall may indicate the location of perforation. Massive pneumoperitoneum in abdomen and pelvis are more likely to be from gastroduodenal and colonic perforation. Free air only around the liver and stomach is suggestive of gastroduodenal perforation and only in the pelvis is concordant with colon and small bowel perforation but colon is more likely. We also describe the most frequent causes of perforation.Conclusion: CT is the first choice imaging method to correct diagnosis of the presence, site and cause of GI perforation and is essential for appropriate patient’s management and surgical planning.

C-485 Extrapulmonary manifestations of tuberculosis: A pictorial review N. Bharwani, K.H. Jogeesvaran, E.J. Goldstraw, S. Grubnic; London/UK

Learning Objectives: 1. To review the pathophysiology of tuberculosis (TB). 2. To discuss the resurgence of the disease in recent years and the changing disease patterns. 3. To discuss and illustrate the extrapulmonary sites of infection.Background: The incidence of extrapulmonary TB has increased with HIV, the de-velopment of drug resistant mycobacterium strains and recent disease resurgence in the western world. It remains a significant problem in developing countries.Imaging Findings: This pictorial review will discuss and illustrate the extrapul-monary manifestations of TB including: a. Nodal disease - most commonly in the cervical chains but does involve all nodal groups. b. Cardiovascular system - peri-carditis. c. Central nervous system - TB meningitis, tuberculomas. d. Genitourinary tract - papillary necrosis, stricture formation. e. Gastrointestinal tract/abdominal viscera - ileocaecal involvement (seen in 80-90%), involvement of solid viscera with miliary dissemination. f. Musculoskeletal system - spondylitis, osteomyelitis and arthritis (typically monoarticular).Conclusion: The radiological features of extrapulmonary TB mimic other diseases creating a diagnostic dilemma. All radiologists need to be familiar with the potential presentations and to maintain a high index of suspicion, particularly in high-risk populations.

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C-486 Post-treatment CT appearances of gastrointestinal stromal tumours and the potential pitfalls in image interpretation M. King1, K. Tung1, C. Lee-Elliott2; 1Southampton/UK, 2Poole/UK" (mrwking@doctors.org.uk)

Learning Objectives: (1) Review the CT imaging features of advanced gastroin-testinal stromal tumours (GIST) at presentation and post-treatment. (2) To highlight the possible misinterpretations, which may occur after Imatinib therapy due to cystic tumour degeneration. (3) To show that the use of PET can increase the specificity of reporting disease response to therapy by demonstrating metabolic activity.Background: GIST represent a heterogeneous group of smooth muscle tumours of the gastrointestinal tract and exhibit a spectrum of behaviour from benign to aggres-sive. Imatinib (Glivec) is a selective inhibitor of KIT mutated tyrosine kinase recep-tors, which are found in 95% of GIST patients. Imatinib treatment has dramatically improved survival and is indicated in the treatment of unresectable and metastatic malignant GIST. Awareness of the changes to imaging appearances after Imatinib are essential for radiologists to contribute correctly to treatment decisions.Imaging Findings: Reduction of tumour size and density following Imatinib is a goal of therapy. However, cystic degeneration in small metastases increases their conspicuity and may be misinterpreted as new lesions. Selected cases from two large regional cancer centres demonstrate the range of post-treatment imaging appearances and highlight this interesting phenomenon.Conclusion: GIST is an interesting disease and the prognosis has improved due to advances in molecular biology leading to new drug therapies. A knowledge of the behaviour of GIST during therapy and the range of CT appearances aids in the correct interpretation of interval scans.

C-487 Early and late-onset acute GvHD following hematopoietic cell transplantation: CT features of gastrointestinal involvement with clinical and pathological correlation H. Brodoefel1, M. Vogel2, W. Bethge2, C. Faul2, M. Wehrmann2, C.D. Claussen2, M.S. Horger2; 1Boston, MA/US, 2Tuebingen/DE (hbrodofe@bidmc.harvard.edu)

Purpose: With the introduction of non-myeloablative hematopoietic cell transplanta-tion (HCT), acute graft-versus-host disease (GvHD) is frequently observed later than the traditional 100 days cut-off. The aim of this study was to compare CT features of gastrointestinal early and late-onset acute GvHD and to correlate findings with clinical and pathological gradings.Methods and Materials: Abdominal CT scans were obtained in 20 patients with early-onset GvHD and 15 subjects with late-onset GvHD. Examinations were assessed for intestinal and extraintestinal abnormalities and findings compared between the two subgroups of GvHD. Distinct CT pathologies as well as CT scores integrating multiple findings were correlated with clinical or pathology grading.Results: Frequent intestinal abnormalities included wall thickening, abnormal enhancement, and excessive fluid-filling (94%, 89%, 94%). While 86% of pa-tients showed concomitant small and large bowel involvement, findings were discontinuously distributed in 54%. Bile tract abnormality proved the commonest extra-intestinal finding (74%). None of the observed pathologies was significantly different between subgroups of early or late-onset disease. Wall thickening and native mucosal attenuation were significantly related to both clinical and pathol-ogy scores. Number of abnormal segments, bowel dilatation, engorgement of the vasa recta and mesenteric fat stranding were linked to clinical grading of GvHD. CT scores that integrate the above abnormalities were associated with clinical and pathological gradings.Conclusion: Acute intestinal GvHD demonstrates a characteristic CT morphology which is independent of its time of onset and, hence, facilitates diagnosis of late-onset GvHD. Correlation of CT morphology with clinical and pathological scorings may help guiding the therapeutic approach.

C-488 Can eating fish be dangerous? Evaluation of fish bone perforation of gastrointestinal tract using CT R. Prada, J. Calatayude, D. Castellon, J. Aguilar, G. Tardáguila, E. Santos, C. Martinez; Vigo/ES (rachelpg@terra.es)

Purpose: Perforation of gastrointestinal tract by ingested fish bones is not infre-quently observed in clinical practice and the correct preoperative diagnosis is seldom made. We describe the role of CT in this diagnosis. Despite the importance of this pathology, it is seldom addressed in the radiological literature.Methods and Materials: Medical history and CT imaging findings of 19 patients with the diagnosis of fish bone perforation of the gastrointestinal tract, made between

January 1997 and December 2006, were retrospectively reviewed. There were 8 women and 11 men ranging from 21 to 97 years old with an average age of 62. Perforations proximal to the stomach were excluded. All diagnoses were confirmed surgically or in follow-up.Results: In all cases, fish bone perforation was visualized on CT examination. The sites of perforation included stomach, small bowel, colon and rectum. The region of perforation was identified on CT as a thickened intestinal segment, localized pneumoperitoneum, regional fatty infiltration or intraabdominal abscess. However, the definitive diagnosis was made by identification of the calcified fish bone. We also described some atypical presentations such as a hepatic abscess or an enterovesical fistula. Demographic data, clinical presentation, radiological findings and treatment were explained.Conclusion: The nonspecificity of the clinical symptoms and the lack of awareness of having ingested the fish bone often make difficult an accurate diagnosis. This study shows the utility of CT in the diagnosis of fish bones perforation of the gas-trointestinal tract and the superiority of CT over clinical history and radiography.

C-489 Evaluation of malignancy of gastrointestinal stromal tumor by FDG positron emission tomography comparing NCCN guideline K. Narushima, S. Okazumi, K. Syuto, G. Ohira, T. Aoyagi, A. Sato, H. Saito, T. Ota; Chiba/JP

Purpose: The purpose of this study is to evaluate the malignant potential of gastro-intestinal stromal tumor (GIST) based on the NCCN guideline using FDG-PET.Methods and Materials: Thirty-five patients who underwent radical resection were enrolled (esophagus 4, stomach 26, ileum 4 and rectum 1). Prior to surgery, PET imaging was performed after injection of 370 MBq of FDG tracer calculating standardized uptake value (SUV) of the tumor. Histological diagnosis was made by immunohistological stain of c-kit and CD34 measuring mitotic count (MC). Malig-nant potential of clinical risk was estimated based on the NCCN risk assessment classification guideline of GIST. We evaluated the relationship between SUV and risk groups to discriminate high-risk group from others.Results: There was a significantly strong correlation between MC rather than between the tumor size (R=0.70, P 0.0001 vs. R=0.45, P=0.0067). SUV of low-risk group was 3.3, intermediate-risk 3.4 and high-risk 7.1. SUV level of high-risk group increased more than that of low and intermediate groups with a statistical difference (P=0.0107, 0.0108, respectively). When the cut-off SUV level for high-risk group was established at 6.0, the positive predictive value and the specificity rate were 88.9 and 95.2%, respectively, and when the cut-off SUV level for high-risk was established at 3.0, the negative predictive value and the sensitivity rate were 90.0 and 92.3%, respectively.Conclusion: FDG-PET may yield a good predictive power with acceptable ability to discriminate high-risk group and a valid clinical imaging to assess the malignancy in the patient of GIST.

C-490 The accuracy of ultrasonography in classification of groin hernias according to the criteria of the unified classification system A. Djuric-Stefanovic, D. Saranovic, A. Ivanovic, D. Masulovic, B. Dobriserevic; Belgrade/RS (avstefan@eunet.yu)

Purpose: Modern concept of type-related individualized groin hernia surgery imposes demand for precise and accurate preoperative determination of type of groin hernia. The aim of this prospective study was to evaluate the accuracy of ultrasonography in classification of groin hernias, according to the criteria of the novel unified classification system. Unified classification divides groin hernias into nine types (grades): type I (indirect, small), II (indirect, medium), III (indirect, large), IV (direct, small), V (direct, medium), VI (direct, large), VII (combined-pantaloon), VIII (femoral), and O (other).Methods and Materials: 125 adult patients with clinically diagnosed or suspected groin hernias were examined. Ultrasonography of both groins was performed with 5- to 10-MHz linear-array transducer. Preoperative ultrasonographic findings of type of groin hernia were compared with the intraoperative findings, which were considered the gold standard.Results: The total accuracy rate of ultrasonography in determination of type of groin hernia was 96% (119 of 124 correct predictions of type of groin hernia compared with surgical explorations). All hernias of the types I, IV, V, VII, and VIII were cor-rectly identified with ultrasonography (sensitivity and specificity 100%). Sensitivity and specificity in classifying type II were 100 and 99%, respectively; type III, 85 and 97%, and type VI, 90 and 99%.Conclusion: Ultrasonography of the groin regions could be used with great accu-racy for precise classification of groin hernias in adults. Each type of groin hernia, according to the unified classification system that we used for classification, has the characteristic ultrasonographic presentation.

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C-491 Pelvic floor dynamic imaging with magnetic resonance: Is evacuation phase mandatory? P.V. Foti, R. Farina, M.V. Coronella, G. Riva, D. Bellomia, G. Politi, G.C. Ettorre; Catania/IT (pietrofoti@hotmail.com)

Purpose: To evaluate the feasibility of the evacuation phase in imaging pelvic floor disorders with Magnetic Resonance (MR) and its impact on the final diagnosis.Methods and Materials: 18 consecutive patients with clinical symptoms of pelvic floor dysfunction underwent dynamic pelvic examination with a closed-configuration MR system while in the supine position. After rectal distension with ultrasound gel, midsagittal FIESTA-cine acquisitions (1 image/sec) were obtained with the patient maximally contracting the sphincter, at rest and straining, without evacuation phase. Then the dynamic exam was repeated adding a final evacuation phase. MR im-ages were blindly evaluated by two radiologists and compared with conventional defecography (CD) available in all patients and considered as the gold standard.Results: MRI without evacuation phase showed sensitivity of 46.2% (95% CI: 19.1%-73.3%), specificity of 80% (95% CI: 44.9%-115.1%), accuracy of 55.6%, predictive positive value (PPV) of 85.7%, predictive negative value (NPV) of 36.4%. MRI with evacuation phase showed sensitivity of 92.3% (95% CI: 77.8%-106.8%), specificity of 80% (95% CI: 44.9%-115.1%), accuracy of 88.9%, PPV of 92.3%, NPV of 80%. MRI with evacuation phase identified 9/10 rectoceles, 5/5 spastic pelvic floor syndrome, 4/4 enterocele. MRI without evacuation phase detected, but underestimated, 5/10 rectoceles and 3/5 spastic pelvic floor syndrome. MRI with evacuation phase identified 2 cystoceles, 1 hysteroptosis and 2 peritoneocele undetected on CD and on MRI without evacuation phase.Conclusion: Adequately instructing the patient, the evacuation phase is easy to perform and provides information of paramount importance for the therapeutic planning.

Head and Neck

Head and Neck Cancer

C-492 Head and neck cancer: What's new? P. Martin, J.M. Millan, R. Hitt, F. Ballenilla, A. Delgado, S. Jimenez; Madrid/ES (patricia3110@yahoo.es)

Learning Objectives: To describe ongoing therapeutic strategies in the manage-ment of locally advanced squamous cell carcinoma of the head and neck (SCCHN). To learn the molecular mechanisms of these new therapies. To discuss the emerg-ing imaging techniques and new approaches when evaluating and predicting the response after treatment.Background: Locally advanced head and neck cancer is currently treated with multiagent-based chemoradiotherapy with expanding role of new therapeutic strategies such as monoclonal antibodies and small molecules. These agents induce angiogenic and intracellular biochemical changes that have effects in the imaging evaluation of tumors.Procedure Details: We review basic concepts about tumor biology and mecha-nisms of molecular therapies. Standard treatment options and current protocols for locally advanced SCCHN are described. We analyze classic imaging techniques and new ways for diagnosis focusing on metabolic and functional imaging and emerging parameters for the radiologist. Morphologic versus molecular imaging as well as challenging response and prognosis prediction are discussed. We support this revision with sample cases at our institution.Conclusion: Molecular-based therapies for patients with SCCHN will become increasingly important with epidermal growth factor pathway being the principal network. The development of novel imaging modalities will help characterize the molecular alterations of these therapies in order to optimize patient selection and assess response and prognosis. Angiogenesis is one of the most important pro-cesses in tumor response and there are different studies designed to asses the predictive value of different parameters of dynamic contrast enhanced perfusion computed tomography and magnetic resonance scanning.

C-493 Functional MDCT in preoperative staging of laryngeal and pharyngeal carcinomas J. Pamies Guilabert, P. Braun, F. Gomez Muñoz, V. Ballester Leiva; Valencia/ES (pamies_jos@gva.es)

Learning Objectives: Show the utility of different functional tests for identification and staging of laryngeal and pharyngeal tumors by means of MDCT. Get to know the best functional test depending on the studied area. Describe the applied tech-nique, the explanations to the patients, recommendations and necessary details to optimize the functional exploration of the cervical region.Background: On MDCT, identification and evaluation of the extension of small tumors of the oral cavity, pharynx and larynx is difficult, as these areas usually are neither distended nor symmetric. The functional exploration obtains symmetry and distension of exactly the area to study, allowing identifying minimal mucosal or submucosal thickening.Procedure Details: From January 2006 to August 2007, 56 functional MDCTs (Toshiba Aquilion 64) were performed in patients with suspicion or diagnosed tumors of the oral cavity, pharynx or larynx. In all patients a standard acquisition and a functional exploration depending on the studied area was obtained. In tumors of the nasopharynx and hypopharynx Valsalva´s maneuver was performed, in tumors of the oral cavity and oropharynx modified Valsalva´s maneuver and in tumors of the larynx /E/phonation. The volumetric acquisition of 64-row CT allows obtaining perfect coronal and sagittal images, especially useful in the staging of tumors of the larynx, base of the tongue and mouth.Conclusion: Functional MDCT is better than standard MDCT in diagnosing and staging of pharyngeal and laryngeal tumors, especially, in small tumors in the lateral pharyngeal recess (fossa of Rosenmüller), gum, faucial tonsil, pyriform sinus, vallecula or glottis.

C-494 Dural invasion by head and neck tumours: Predictive value of MRI A. Borges, I. Fonseca; Lisbon/PT (borgesalexandra@clix.pt)

Purpose: To evaluate the accuracy of MRI in predicting dural invasion by head and neck tumours and to determine the pathologic correlates of dural enhancement adjacent to skull base tumours.

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Methods and Materials: We have retrospectively reviewed the pathology slices and MR imaging studies of 35 patients with head and neck tumours who under-went combined craniofacial resections in a 5 year period (2002 - July 2007). MR features evaluated included: dural enhancement contiguous with primary tumour (maximal width of enhancement), pattern of enhancement (linear, nodular, continu-ous or discontinuous), presence or absence of a hypointense band separating the tumour from the overlying dura, leptomeningeal enhancement, brain edema and parenchymal enhancement.Results: The sensitivity, specificity, and overall accuracy of the MR features evalu-ated were 92.8%, 25% and 71.4% for dural enhancement; 80%, 25% and 46.1% for linear enhancement below 5 mm thick, 80%, 100% and 81.1% for nodular enhancement, 92.8%, 75% and 86.3% for discontinuous enhancement and loss of hypointense band respectively. Leptomeningeal enhancement, brain edema and parenchymal enhancement showed 100% specificity but 42.8%, 64.2% and 42.8% sensitivity, respectively. All patients with dural enhancement thicker then 5 mm on MR had dural invasion on pathology. Pathologic correlates of false posi-tive results of dural enhancement included fibrovascular changes, inflammatory infiltrates and normal dura.Conclusion: The presence of linear dural enhancement above 5 mm thick, nodular enhancement and loss of the hypointense band separating the tumour from the overlying dura are good predictors of dural invasion on gadolinium enhanced MR imaging studies.

C-495 Utility of diffusion-weighted magnetic resonance imaging in the detection of recurrent head and neck tumors K. Michimoto, S. Fujii, T. Kan, S. Kakite, Y. Kanasaki, T. Ogawa; Yonago/JP

Purpose: Post-therapeutic changes hamper the detection of recurrent head and neck tumors by imaging procedure. The aim of this study was to evaluate the utility of diffusion-weighted (DW) MR imaging in the detection of recurrent head and neck tumors.Methods and Materials: This study included 30 patients clinically suspected of recurrent head and neck tumors after surgery (n=6), radiotherapy (n=10), and both (n=14). MR images were reviewed independently by two experienced head and neck radiologists. After DW MR images were reviewed firstly, routine MR images (T1WI, T2WI, post-contrast T1WI) were reviewed on another day. We assigned confidence scores (1=definitely absent, 2=probably absent, 3=equivocal, 4=prob-ably present, 5=definitely present) to each abnormality on DW MR imaging. To assess the performance of DW imaging for diagnosing recurrent head and neck tumors, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated.Results: We obtained the sensitivity of 94.4%/100%, specificity of 88.1%/88.1%, positive predictive value of 77.2%/78.3%, and negative predictive value of 97.3%/100%, respectively by DW MR imaging and routine MR imaging.Conclusion: DW MR imaging performance of detecting recurrent head and neck tumors is nearly equivalent to the routine MR imaging. DW imaging helps to pick up the recurrent tumors in the head and neck regions influenced by post-thera-peutic changes.

C-496 Characterization of cervical lymphadenopathy with apparent diffusion coefficient value J. Yu1, D.-W. Park2, J. Kim1, C.-K. Hahm2, S. Kim2, Y. Kim2, C.-K. Park2, J.-N. Heo2; 1Seoul/KR, 2Kuri/KR (ivoryoo@naver.com)

Purpose: To evaluate the usefulness of apparent diffusion coefficient (ADC) value for differentiation between various causes of cervical lymphadenopathy.Methods and Materials: Diffusion weighted echo-planar MR imaging for ADC value was performed on 17 metastatic nodes, 16 lymphomatous nodes, and 16 benign nodes. The ADC Maps of cervical lymph nodes were acquired by using two b factors, 0 and 800 s/mm2. The ADC values were measured in cervical lymph nodes. Each group of metastatic, lymphomatous and benign inflammatory nodes was statistically compared with ADC values, according to histologic and clinical features.Results: Mean ADC values (X10-3 mm2/s) of metastatic, lymphomatous and benign nodes are 0.662 0.154, 0.475 0.589, and 0.823 0.123, respectively with mean ADC value of malignant nodes including metastatic and lymphomatous nodes, 0.571 0.150. Mean ADC value is significantly lower in malignant nodes than benign nodes (P 0.001) and also significantly lower in lymphomatous nodes than metastatic lymph node (P 0.001). An ADC value of 0.650 X 10-3 mm2/s as a cut off value for differentiating malignant from benign lymph nodes is obtained with the highest accuracy of 83.6% with 78.8% sensitivity and 93.8% specificity. Cut off value of 0.587 X 10-3 mm2/s for differentiating lymphomatous and metastatic

lymphadenopathy is obtained the highest accuracy of 84.8% with 100% sensitivity and 70.6% specificity.Conclusion: ADC value can help the characterization and differentiation of cervical lymph nodes, especially in between patients with benign, metastatic and lympho-matous nodes. ADC value seems to be supportive tool for predicting the character of cervical lymphadenopathy before optimal management.

C-497 Electrical permittivity as a new imaging tool in the evaluation of sonografically suspicious lymph nodes A. Malich1, C. Mauch1, D. Hentrich1, A. Kott1, J. Böttcher2, A. Hansch2; 1Nordhausen/DE, 2Jena/DE (ansgar.malich@shk-ndh.de)

Purpose: The incidence and diagnostic value of altered electrical permittiv-ity of lymph nodes was tested and matched to well established sonographical features.Methods and Materials: 368 lymph nodes were analyzed sonographically including the following features: hilar vascularization, Solbiati-Index, capsula, calcifications, necrotic parts, echogeneity of the nodes and electrical permittivity. All lymph nodes underwent histological verification.Results: 151/166 malignant and 49/202 benign lymph nodes showed a significantly increased permittivity of current suggesting a sensitivity of 91% and a specificity of 75.7%. 148/166 malignant nodes had no hilus (89.2%) vs. 55/202 benign nodes (27.3%). Solbiati-Index 1.5 is a highly predictive value for malignancy (p .001). Capsulation was rather uncommon: 43/166 malignant nodes and 7 benign nodes had a fibrotic capsula (25.9% and 3.5%, respectively). Echogeneity was not help-ful to discriminate metastatic and inflammatory nodes. Sonographically visible necrotic components were more common in malignant lesions: 59/166 (35.5%) vs. 15/202 in benign nodes (7.4%). Increasing Solbiati-index causes a slight loss of increased focal permittivity (index up to 1.5: 92.7% vs. 84.6% index 2). Permittivity is influenced by the geometrical structure and the depth localization of the nodes and fairly uninfluenced by other sonographic features.Conclusion: The best predictive value in lymph node analysis is the hilar vascular-ization as well as the Solbiati-Index. Electrical permittivity is, however, significantly modified by malignant tissue alterations and, thus, can be used as an adjunct in unclear cases. Most other sonographic features are less accurate compared to permittivity.

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Head and Neck

Maxillofacial Imaging

C-499 Paranasal sinus disease: Did you think on lymphoma? M. Martinez Galdamez, B. Brea Alvarez, S. Cornide Santos, C. García Roch, J. Hernanz Padial, L. Nombela Cano; Madrid/ES (mariomgaldamez@hotmail.com)

Learning Objectives: To illustrate characteristic imaging findings of the lymphomas affecting paranasal sinuses. To review and become familiar with the differential diagnosis. To demonstrate the role of themultidetector CT and MRI in the diagnosis and management of the sinus disease.Background: Lymphomas of the paranasal sinuses, although rarely encountered, enter in the differential diagnosis of many other nasosinusal tumors. The radiologist must consider them because lymphomas have a rapid progression and poor prog-nosis, and so the diagnosis is vital. Although the final diagnosis requires histological confirmation, CT and MRI are two necessary and complementary techniques for a complete and good evaluation. In this exhibit, we review the literature and present several cases of lymphomas from our database.Procedure Details: The high resolution of the CT multidetector and MRI, and the possibility of multiplanar reconstructions, makes these techniques essentials for diagnosis sinus diseases. While the CT accurately evaluates the bony erosion or destruction, the MRI defines the soft tissue invasion, the invasion of the orbital structures and the spreading to the central nerve system. A retrospective review from our hospital was performed in patients with various cases of paranasal sinus tumors as non-Hodgkin lymphoma, granulocytic lymphoma, nasal NK/T-cell lym-phoma and plasmacytoma, describing and comparing the main imaging findings with literature.Conclusion: Although lymphomas of the paranasal sinuses are infrequent, the radiologist should include them on the differential diagnosis. CT and MRI are two complementary non-invasive excellent modalities for this purpose.

C-500 Differential diagnosis of mandibular lesions in adults: Findings on plain radiographs, bone scintigraphy, CT, MRI and PET scanning I.M. Brennan, G. Murphy, P. Beddy, P. Govender, J.F.M. Meaney; Dublin/IE

Learning Objectives: To illustrate the spectrum of lesions presenting within the mandible to a busy tertiary head and neck referral service. To highlight the typical and atypical features of both benign and malignant lesions.Background: Mandibular lesions are uncommon, but can be identified in patients with local symptoms, patients presenting with floor of mouth tumours or incidentally in patients undergoing evaluation of the neck for a variety of indications. Differen-tial diagnosis of mass-like lesions includes dentigerous cysts, ameloblastomas, odontogenic keratocysts, osteomas, metastases, plasmacytoma/myeloma and primary bone tumours. Fibrous dysplasia and Pagets disease also affect the man-dible. Causes for destructive permeative lesions also include osteomyelitis, dental abscess and direct tumour invasion from floor of mouth lesions.Imaging Findings: We illustrate the spectrum of findings on plain radiographs, bone scintigraphy, CT, MRI and PET scanning and emphasise features that help differentiate inflammatory lesions, and benign and malignant tumours. In particular, we emphasise the patterns of bone abnormality on MDCT, and marrow signal abnormality and enhancement pattern on MR that aid in confident diagnosis.Conclusion: We present the differential diagnosis of mandibular lesions and em-phasise the findings associated with inflammatory, benign and malignant lesions.

C-501 The many causes of antral bowing sign I.A. Alorainy; Riyadh/SA (alorainy@ksu.edu.sa)

Learning Objectives: To illustrate and discuss the many causes of anterior dis-placement of the posterolateral wall of the maxillary sinus “antral bowing sign”.Background: The antral bowing sign is caused by anterior displacement of the posterolateral wall of the maxillary sinus. The sign has classically been described with juvenile angiofibroma; however, any slow growing mass arising from or extending into the retromaxillary space (pterygopalatine fossa) could potentially cause the sign.Imaging Findings: Retromaxillary space (pterygopalatine fossa) is a cleft located posterior to the maxillary sinus and anterior to the sphenoid bone. The space is bounded medially by the palatine bone and communicates laterally with the infra-temporal fossa via the pterygomaxillary fissure. The space contains loose fatty tissue, the maxillary division of the trigeminal nerve, the pterygopalatine ganglion,

the third part of maxillary artery, and network of veins. Slow growing masses in the retromaxillary space tend to remodel the thin posterolateral wall of the maxil-lary sinus giving the so-called antral bowing sign, which is readily seen on the plain lateral radiograph of the sinuses and more often on cross sectional imaging. Several inflammatory conditions as well as benign and malignant neoplasms can cause this sign. We illustrate this sign in lymphoma, leukemia, neurofibroma, and rhabdomyosarcoma in the head and neck regions. We also illustrate the sign in osseous meningioma and parotid tumor.Conclusion: Antral bowing sign is not specific for a particular lesion and can be seen in several inflammatory and neoplastic conditions arising from or extending into the retromaxillary space.

C-502 Nasal cavity tumours: The differential diagnosis and the role of cross-sectional imaging F. Jabeen, R. Rahim, N. Desai; Manchester/UK (Farrah.Jabeen@gmail.com)

Learning Objectives: To be aware of the wide range of nasal cavity tumours. To review the differential of tumours that occur in the nasal cavity. To describe and illustrate the appearances of such tumours on cross-sectional imaging and to emphasize the role of CT and MRI in the staging and pretreatment planning of nasal cavity tumours.Background: Primary nasal cavity carcinomas are rare and the clinical symptoms are not specific for a particular tumour type. Tumours of the nasal cavity are divided equally between benign and malignant types. The differential for primary nasal cavity tumours is diverse and they are classified as epithelial or non-epithelial. Knowledge of the anatomy of the nasal cavity and surrounding structures is paramount for the staging and evaluation of the patient. We report on the use and the role of high-resolution CT and MRI in achieving this.Imaging Findings: MR imaging in combination with high-resolution CT gives essential information on the origin of the tumour and its spread and invasion of vital structures. The use of contrast and MR weighting helps to evaluate tumour margins and to differentiate neoplastic from non-neoplastic tissue. We illustrate the appearances of nasal cavity tumours on cross-sectional imaging, including cases of inverted papilloma, esthesioneuroblastoma, haemangiopericytoma, melanoma, adenoid cystic carcinoma, squamous cell carcinoma and lymphoma.Conclusion: CT and MRI play a vital role in narrowing the differential of nasal cavity tumours and in the assessment of their extent for purposes of staging and pretreatment planning.

C-503 Ortopantomography and CT imaging of the buccal space: Normal anatomy and pathology A. Peralta, P. Jimenez, J.A. Dieguez, R. Conde; Jerez/ES (34093aps@comb.es)

Learning Objectives: To illustrate the anatomy so that it serves as an introduction to the use of ortopantomography and CT images. To review the indications of CT in the pathology of the buccal space. To differentiate benign and malignant disease.Background: Ortopantomography displays the mandible and maxilla, which are curved structures, on flat, easily viewed images. However, supplementary CT im-ages may be required. The purpose of imaging is to define the likely anatomic origin and the extent of the lesions. With a thorough knowledge of the normal anatomy and the pathology of the buccal space, the radiologist can interpret the images and make the diagnosis.Imaging Findings: Anatomy, congenital variants and common developmental abnormalities are revisited here through correlating the perspective provided by the conventional radiograph with the multiplanar CT images. The usual pathology, infec-tions and cystic lesions are illustrated and differentiated from malignant disease.Conclusion: There are various pathologies that can occur in the buccal space. The knowledge of the anatomy of the buccal space helps primarily to determine the origin and extent of the lesions. Ortopantomography and CT imaging findings can be helpful to the radiologist in diagnosing the specific etiology of the lesions.

C-504 Classification and complications of mandibular fractures A. Hameeduddin, L. Makalanda, S. Stuart, A. Malhotra, O. Chan, R. Katz; London/UK (ayshea@doctors.net.uk)

Learning Objectives: To revise the anatomy of the mandible and highlight the importance of muscular forces, arterial supply and innervation. To illustrate the frequency and distribution of mandibular fractures associated with different mecha-nisms of injury using multi-modality imaging. To recognise important associated complications following mandibular fractures including secondary fractures, and

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thoracic and cervical injury, in order to provide appropriate management and intervention.Background: The mandible plays a major role in speech, mastication and swal-lowing, and its fractures are therefore associated with high morbidity. Fractures of the mandible are amongst the most common fractures of the facial skeleton; therefore, knowledge of the frequency and distribution of fractures is important. This exhibit aims to highlight the key radiological appearances of common sites and different types of mandibular fractures. The exhibit also aims to illustrate important complications, which may arise and should be considered.Imaging Findings: Plain film and CT reconstructions will demonstrate mandibular fractures according to the anatomical classification. Selected CT images of the neck, chest and associated plain film radiography will illustrate important complications including secondary fractures, dislocation of the temporomandibular joint, chest trauma (pneumomediastinum, pneumothoraces) and cervical emphysema.Conclusion: The anatomical classification of mandibular fractures and the key radiological appearances are appreciated. The secondary complications that may arise, and should be considered, in all cases are highlighted.

C-505 Marginal intracranial cysts in sinonasal tumours: Diagnostic accuracy for olfactory neuroblastoma A. Borges; Lisbon/PT (borgesalexandra@clix.pt)

Purpose: To access the frequency of marginal cysts in sinonasal neoplasms with intracranial invasion; to determine whether the presence of cysts at the intracranial border of a sinonasal neoplasm is specific for olfactory neuroblastoma.Methods and Materials: We have retrospectively reviewed pre-therapeutic imaging studies of 79 patients with sinonasal malignancies for the presence of intracranial invasion (intra- or extradural) and for the presence of cysts at the tumour-brain interface. Marginal cysts were defined as well-defined, rounded, hypo-or hyperat-tenuating lesions on CT and fluid like signal intensity lesions on MR, rounded, with thin, linear peripheral enhancement, with at least 3 mm in size, seen in two different planes.Results: Thirty three per cent of cases invaded the skull base. In 65% of cases, the tumour remained extradural and in 35% transgressed the dura. Among tumours with skull base invasion, marginal intracranial cysts were absent in 21 cases (81%) and present in 5 cases (19%). In 2 cases with marginal cysts, tumour remained extradural and in 3 cases transgressed the dura. The pathologic diagnoses of the 5 cases with marginal peripheral cysts were: olfactory neuroblastoma in 2, undif-ferentiated sinonasal carcinoma, adenocarcinoma of intestinal type and squamous cell carcinoma in 1 case, respectively.Conclusion: Diagnostic specificity of marginal cysts at the intracranial border of sinonasal neoplasms have been overemphasised in the literature as they can be seen in a variety of sinonasal neoplams. As those associated with intracranial neoplasms they may correspond to neoplastic cysts or entrapment of CSF at the tumour-brain interface.

C-506 Quantitative mandibular bone changes in women E. Arana, F. Benet, L. Martí-Bonmatí; Valencia/ES (Luis.Marti@uv.es)

Purpose: Bone density is an important factor for dental implants. A method to mea-sure bone quality and quantity is presented, showing evolution in women span life.Methods and Materials: We studied 108 women (age range 21-92 years) by CT prior to dental implants. Menopause status and dentition status were recorded. Patients with systemic diseases and osteoporosis were excluded. Images were semi-automatic segmented using Simplant 10 (Materialise, Brussels, Belgium). Bone was classified in medullar, lingual and buccal corticals and in both posterior and anterior regions. Quantitative bone CT (QBCT) from nine areas was measured in Hounsfield units in every patient.Results: There were no statistical differences between anterior or posterior buc-cal corticals. In the posterior mandible, lingual cortical was always statistically higher than buccal (p 0.05). Medullar midline bone peaked in the 61-70 years vs. 21-30 years (lowest value) (p 0.05). Anterior teeth loss resulted in statisti-cally higher medullar values in the anterior sector (p 0.05) vs. no teeth loss, with no changes in cortical bone. Medullar bone in menopause shows statistically higher values (p 0.01) compared to no menopause. However, lingual corticals showed statistically lower values in the menopause status (p 0.05) compared to no menopause.Conclusion: Mandible bone follows different patterns according to their location anterior or posterior to mental foramen. Anterior teeth loss resulted and increased trabecular bone density with no changes in cortical bones. These results differ from Lekholm and Zarb bone classification I and II. This method should also increase the accuracy of QBCT for dental implants and bone research.

Head and Neck

Temporal Bone

C-507 Temporal bone lesions: A pictorial essay R.S. Glikstein, L. Rosenbloom, M. Levental; Montreal, QC/CA (rglikste@rad.jgh.mcgill.ca)

Learning Objectives: To demonstrate the imaging features of various pathologies affecting the temporal bone.Background: CT scan and/or MRI examinations were performed in fourteen patients referred from the department of otolaryngology with symptoms related to the temporal bones. The pathologies included venous hemangioma of the external auditory canal, viral otitis externa, vestibular dysplasia, glomus tympanicum, glomus jugulare, dilated vestibular aqueduct, otospongiosis, osteomyelitis, schawannoma of the geniculate ganglion, schawannoma of the eighth cranial nerve, congenital cholesteatoma, tuberculosis, epidermoid cyst, and complicated cholesteatoma with cerebellar abscess. Brief discussions of the different pathologies presented will be provided.Imaging Findings: Temporal bone disease can present with a variety of symptoms, most of which manifest as neurosensory deficits, including hearing impairment or loss, tinnitus, vertigo, and facial paralysis. Other manifestations include fever, headaches, and external auditory canal discharge. Clinical history alone is usually insufficient to establish a definitive diagnosis. The exquisite spatial resolution of multidetector CT images and tissue contrast of MRI images can reliably visualize even minute pathologies and often lead to a confident diagnosis.Conclusion: A wide variety of pathologies affect the temporal bone. The clinical history is often important for directing the radiologist towards the optimal imaging study. CT and MRI are usually invaluable, either alone or ideally in concert, for the diagnosis and surgical planning of temporal bone disease.

C-508 Pocket atlas of lesser known anatomical variants in the temporal bone on CT S. Dekeyzer, V. VandeVyver, M.M. Lemmerling, K. Verstraete; Gent/BE (sofiedekeyzer@skynet.be)

Learning Objectives: To illustrate lesser known anatomical variants in the temporal bone on CT, and to demonstrate which diseases they can be confused with, or which pathologies they can cause.Background: Temporal bone anatomy is complicated with many normal variants, of which some are infrequently seen or lesser known. The unaware radiologist can confuse them with pathology. Other lesser known normal variations are important to report because they can cause pathology.Imaging Findings: Foramen of Huschke, the subarcuate canal, emissary vein canals, vestibular nerve canals, and many other anatomical structures with linear morphology can be confused with fracture lines on CT examinations. This atlas illustrates in detail how to avoid such misinterpretations. The cochlear cleft is another pathology mimicker on CT. It is a hypodense appearing fissula antefenestram seen in the healthy pediatric population and should not be confused with otosclerosis. Arachnoid granulations of the posterior temporal bone wall can appear close to the vestibular aqueduct and lookalike endolymphatic sac tumors. On CT, both entities can be differentiated by demonstrating the absence of bone spicules and calcifications in such granulations. They however should be reported since they are known to cause CSF leakage, otorrhea or meningitis.Conclusion: Knowledge of lesser known anatomical variants in the temporal allows correct interpretation of confusing findings on temporal bone CT examinations.

C-509 A bilingual multimedia online lecture program for multiplanar temporal bone anatomy in high resolution CT R. Talanow1, S. Waldeck2; 1Cleveland, OH/US, 2Hamburg/DE (roland@talanow.info)

Learning Objectives: To create an easily accessible multimedia program for teach-ing the cross section anatomy of the temporal bone in lecture style, enhanced by narration in addition to pertinent images and text and in several languages for an international audience.Background: The temporal bone anatomy is complex and difficult to understand for the less experienced radiologist. Nevertheless it is important to understand the cross section anatomy in detail to determine the otorhinolaryngologist´s preoperative planning. Lectures are optimal ways to teach study material because in addition to the visual perception in form of images and text, the auditory potentials in form of

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narration are utilized. An easily accessible multimedia program to teach temporal bone anatomy which combines lecture style narration with pertinent images and text is desirable.Procedure Details: This program is available online and is based on Flash (Macro-media/Adobe Systems) technology, which is supported by most internet browsers. Lectures are set up similarly to PowerPoint (Microsoft) based presentations. A com-plete curriculum for temporal bone anatomy is provided. Pertinent high resolution CT images for temporal bone anatomy in different planes are accompanied with textual information and enhanced by narration of the lecturer in several languages (German and English).Conclusion: The authors present a multimedial, bilingual web-based program to facilitate the understanding of the complex cross section anatomy of the temporal bone by using audiovisual teaching material aiming real lectures. This program is easy to navigate and online access makes it available for a worldwide audience.

C-510 Klippel-Feil syndrome and associated ear anomalies: CT findings A. Arslanoglu, N. Yildirim; Van/TR (atilla02002@yahoo.com)

Learning Objectives: Klippel-Feil Syndrome (KFS) is a congenital segmentation anomaly of the cervical vertebrae manifested as short neck, low hair line and limited neck mobility. Various systemic malformations may also accompany the syndrome including wide variety of ear pathologies in all three compartments of the ear (external, middle and inner ear) as well as of internal acoustic canal and vestibular aqueduct.Background and Imaging Findings: We present here 20 KFS cases, of which 12 (60%) displayed most of the reported ear abnormalities consisting of microtia, external ear canal stenosis, chronic ear inflammations and their sequels, deformities of the tympanic cavity and ossicles, inner ear dysplasies, deformed internal acoustic canal and wide vestibular aqueduct, which are proved by audiological-otological and/or temporal bone Computed Tomography (CT).Conclusion: This series represents one of highest reported rate of ear involvement in KFS. A novel cochlear deformity was also identified. We found no correlation between the identified ear pathologies and skeletal and extra-skeletal malforma-tions. Genetic nature of the syndrome was supported by the existence of affected family members in 4 (20%) of the cases.

C-511 How to find the way out of the canals and labyrinths of temporal bone: Normal anatomy of temporal bone in computed tomography and gross anatomical specimens G.J. Staskiewicz, E. Czekajska-Chehab, A. Trojanowska, S. Uhlig, A. Szabelska, A. Torres, K. Torres, R. Maciejewski, A. Drop; Lublin/PL (grzegorz.staskiewicz@am.lublin.pl)

Learning Objectives: To review the normal anatomy of temporal bone in multislice computed tomography (MSCT). To present the best projections for visualization of the most important anatomical structures, to remember and recall the main anatomical variants of temporal bone structures seen in MSCT as well as present some mnemonics useful for learning anatomy of the temporal bone.Background: During a course on the diagnostic imaging of the temporal bone recently organized at our institution, the feedback from participants showed a great need for a detailed, practical knowledge of normal anatomy of the temporal bone. The authors concluded that the presentation of normal anatomy of the temporal bone with its most common variants would be a valuable didactic tool.Imaging Findings: Normal anatomy of the temporal bone is presented with regard to anatomical specimens and MSCT images. The authors present the feasibility of multiplanar and curved reformations and volume rendering applica-tions, such as virtual endoscopy and 3D models, for the identification of particular structures of temporal bone. Furthermore, the most common anatomical variants are presented.Conclusion: MSCT allows detailed visualistion of all the important anatomical structures of the temporal bone. Appropriate knowledge of its anatomy and com-mon anatomical variants is essential for evaluation in all pathological conditions. Postprocessing methods are extremely useful in explaining the complex anatomy of the temporal bone, especially for in-training readers, as they allow better visu-alization and are a valuable teaching tool.

C-512 Pulsatile tinnitus: A diagnostic approach N.S. Alam, Y. Jain, A. Anbarasu; Birmingham/UK (nusratalam@yahoo.com)

Learning Objectives: To demonstrate the aetiologies of pulsatile tinnitus using conventional imaging modalities, especially CT and MR.Background: Pulsatile tinnitus refers to the patient who perceives a rhythmic sound. When pulse-synchronous, this may be due to a correctable vascular abnormality. The imaging pathway for pulsatile tinnitus focuses on identifying these causes and differs from the approach for non-pulsatile tinnitus.Imaging Findings: Bone algorithm CT imaging is used to demonstrate the differ-ence between glomus tympanicum tumours and glomus jugulare tumours, whilst highlighting the more extensive operative intervention required for the latter. The images highlight the abnormalities of the major vessels of the brain as a cause for pulsatile tinnitus, including internal carotid artery dissection, ectatic basilar artery, dehiscent jugular bulb and jugular vein thrombosis. The importance of reviewing images on bone algorithms and using multiplanar reconstructions is highlighted. Examples display the use of MR imaging as an adjunct to CT. MR angiography can be used to demonstrate vascular abnormalities, such as carotid artery stenosis. In the event of cross-sectional imaging studies being normal, conventional angiography may demonstrate dural vascular malformations.Conclusion: Tinnitus is a common symptom, which if pulsatile warrants further investigation. Knowledge of the aetiology and the various imaging modalities is required to achieve a confident diagnosis and exclude patients with no demon-strable abnormality.

C-513 Computed tomographic findings in the temporal bone of patients with osteogenesis inperfecta S. Mehiri, S. Bourkhis, A. Salem, F. Ben Amara, H. Rajhi, R. Hamza, N. Mnif; Tunis/TN (azza.salem@dr.com)

Learning Objectives: To illustrate the CT findings in the evaluation of temporal bone injury in patients with osteogenesis imperfecta, known as Lobstein disease.Background: Five patients (18-28 years old) from two differents families affected with Lobstein disease were addressed to explore bilateral mixed hearing loss. One of them had bilateral facial nerve paresis. For all patients, a physical examination was performed, and an audiogram and a high-resolution CT were obtained as 1 mm sections in the transverse and coronal planes without administration of intravenous contrast material.Imaging Findings: The audiogram found in all five cases a mixed conductive and sensorineural hearing loss. The stapedial reflex revealed an ossicular abnormal-ity and stapedo-vestibular ankylosis in three cases. CT of petrous temporal bone demonstrated in all cases bilateral and symmetric unmineralized foci around the cochleae and the vestibules similar to an otospongiosis 4B with normal aspect of the ossicles. The facial nerve canal was involved in the dysplastic process in one case. A stapedial footplate fixation was identified in one case and hyperpneumatic petrous bone in four cases. Other variants like a high jugular fossae were also found in two cases. Conclusion: Osteogenesis imperfecta is a rare genetic disorder of the connec-tive tissue, which sometimes causes adult-onset hearing loss due to otic capsule involvement with sensorineural deficit. The CT scans had a preponderant place to diagnose bone impairment of the petrous bone causing hearing loss.

C-514 Separate visualization of endolymphatic space, perilymphatic space and bone by a single pulse sequence: Acquisition of 3D-inversion recovery sequence utilizing real reconstruction after intratympanic Gd-DTPA administration at 3 Tesla S. Naganawa, H. Fukatsu, T. Nakashima, M. Kawamura; Nagoya/JP (naganawa@med.nagoya-u.ac.jp)

Purpose: After 24 hours of the intratympanic administration of Gd-DTPA (Gd), Gd mainly distribute in perilymphatic space. 3D-FLAIR can delineate endolymphatic space from perilymphatic space, but not from surrounding bone. By setting the inversion time of 3D-inversion recovery TSE (3D-IR-TSE) sequence between the null point of Gd-containing perilymph fluid and that of non-Gd-containing endolymph fluid, we speculated that 3D-IR-TSE with real reconstruction (3D-real-IR-TSE) could separate the signal of perilymph (positive value), endolymph (negative value) and bone (zero). The purpose of this study was to evaluate if 3D-real-IR-TSE could successfully delineate the signal difference of endolymph, perilymph and sur-rounding bone in patients.

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Methods and Materials: Thirteen patients with the clinically suspected endo-lymphatic hydrops (9 Meniere’s disease, 2 delayed endolymphatic hydrops, and 2 acute low tone sensorineural hearing loss) underwent intratympatic administra-tion of Gd. All scans were performed on a 3 Tesla MRI scanner after 24 hours of intratympanic injection of diluted Gd. 3D-T1-weighted FLASH, CISS, FLAIR and real-IR-TSE were obtained.Results: In all patients, low signal of endolymphatic space in the labyrinth on 3D-FLAIR was observed in the anatomically appropriate position and it showed negative signal on 3D-real-IR-TSE, and low signal area of surrounding bone on 3D-FLAIR showed near zero signal on 3D-real-IR-TSE. Gd-containing perilymphatic space showed high signal on 3D-real-IR-TSE.Conclusion: By optimizing inversion time, endolymphatic space, perilymphatic space and surrounding bone or air can be separately visualized on single image using 3D-real-IR-TSE. This method might open the door for the quantitative evalu-ation of endolymphatic space disease in clinical setting.

C-515 Dehiscence of the superior semicircular canal: Correlation of high-resolution CT findings with vestibular symptoms A. Diaz de Otalora Serna, A.I. Ezquerro, O. Rodriguez San Vicente, B. Mateos Goñi, R. Villoria, M.A. Crovetto de la Torre, L. Larrea Bilbao; Bilbao/ES (ainhoadiaz@seram.org)

Purpose: To determine the prevalence of superior semicircular canal dehiscence (SSCD) on CT scans. To prospectively evaluate in 136 patients the association between SSCD and the presence of vestibular symptons and assessing the rela-tion of this radiologic abnormality as a cause of vertigo and subsequent impact on patients’ management.Methods and Materials: High-resolution temporal bone CT was performed in 125 patients over a 7-month period. Clinical data were prospectively registered. The presence of bony dehiscence of superior semicircular canal was evaluated with oblique reformated images in 33 patients with vestibular symptoms and in 92 patients without vertigo who underwent temporal bone CT for other reasons. Patency and thickness of the bone overlying the superior semicircular canal was measured. Temporal bone pneumatization degree and coexistence of tympanic tegmen defects and posterior semicircular canal dehiscence were also assesed. Differences in SSCD frequencies between the two groups were tested for signifi-cance by using the Fisher exact test analysis.Results: The overall frequency of SSCD was 13% (22 of 136 patients): 7 (5.6%) asymptomatic versus 10 (8%) symptomatic patients had radiologic evidence of SSCD on high resolution CT scans (p 0.003 Fisher exact test). There was not found association between tympanic tegmen defects or posterior semicircular canal dehiscence and SSCD (p 0.35).Conclusion: The prevalence of SSCD is significantly higher in patients presenting vestibular signs and/or symptoms. Since semicircular canal dehiscence is poten-tially treatable, high resolution temporal CT has an important role depicting this abnormality in patients with clinically suspected SSCD.

Head and Neck

Thyroid/Parathyroid

C-516 Contrast enhanced ultrasound: A useful tool for evaluation of percutaneous ablation of thyroid nodules L. Tarantino; Frattamaggiore/IT (luciano_tarantino@fastwebnet.it)

Learning Objectives: Understand the value of pre-treatment and post-treat-ment Contrast Enhanced Ultrasound (CEUS) when performing ablation of thyroid nodules.Background: Percutaneous ablation of benign thyroid nodules are gaining increas-ing interest. Color-Doppler-Ultrasound (CDUS) and scintigraphy are the standard techniques for the assessment of the efficacy of ablation. Howewer, CDUS shows low sensitivity for slow blood-flow and microcirculation, while scintigraphy shows high sensitivity but poor space resolution.Procedure Details: 1) We describe the use of CEUS in pre-treatment evaluation of vascularity and post-treatment assessment of necrosis in a series of patient with thyroid nodules treated with percutaneous ethanol injection, radiofrequency ablation, and percutaneous laser ablation. 2) We illustrate the value of CEUS for targeting still viable portions of the lesion after one or more sessions of percutane-ous ablation. 3) We demonstrate the advantages of CEUS over CDUS for all the above-mentioned purposes.Conclusion: In contrast with CDUS and scintigraphy, CEUS provides accurate mapping of intralesional microcirculation with a precise targeting of still viable tis-sue and can also be used during and soon after treatment for prompt evaluation of results.

C-517 Correlation between ultrasound patterns of parathyroid glands and parathormone levels in secondary hyperparathyroidism C. Vulpio, A. De Gaetano, F. Piludu, M. Ciliberti, N. Panocchia, S. Giungi, G. Maresca; Rome/IT (gmaresca@rm.unicatt.it)

Learning Objectives: To evaluate the different ultrasonographic (US) patterns of parathyroid glands (PTG) related to secondary hyperparathyroidism (SHPT) degree and to codify the US changes related to progression of SHPT.Background: US has been used to detect PTG in haemodialysis patients with SHPT, who are candidates to parathyroidectomy. Nevertheless, it has been recently suggested that the echo structural (ESP) and blood supply patterns (BSP) are useful to detect diffuse or nodular hyperplasia.Procedure Details: A total of 20 moderate SHPT (ModSHPT; PTH 300-800 pg/ml) and 15 severe SHPT (SevSHPT; PTH 800 pg/ml) underwent US. The number, the maximum longitudinal diameter (MLD), ESP (1 hypoechoic, 2 slightly heteroge-neous, 3 highly heterogeneous, 4 nodular) and BSP (low or high vascularization) of the largest PTG were determined. ThePTG number and MLD were correlated to PTH and calcium levels.The MLD of ModSHPT and SevSHPT was, respectively, 7.2 2.3 mm and 15 5.1 mm (M SD; P 0.001). Most ModSHPT showed a single PTG with an MLD 1 cm associated with 1-2 ESP and low BSP. Almost all SevSHPT exhibited more than one PTG associated with 3-4 ESP and high BSP.Conclusion: The PTG US patterns that resulted tightly correlated with the degree of SHPT. Beyond PTH 800 pg/ml, most of the points exhibited more than one PTG with an MLD 10 mm, associated more frequently with heterogeneous or nodular patterns and to hypervascularity. The PTG US may be a good adjunctive marker for SHPT severity.

C-518 Ultrasound-guided fine needle aspiration of thyroid nodules: A how to do DVD-Rom-based audiovisual guide D.D. Cokkinos, I. Theotokas, A. Plagou, K. Pahos, E. Skoulikaris, P.S. Zoumpoulis; Athens/GR (ddcokkinos@yahoo.gr)

Learning Objectives: 1. To outline the basic principles of ultrasound-guided fine needle aspiration (FNA) of the thyroid. 2. To present the examination technique. 3. To illustrate its main indications and limitations. 4. To master the skill of performing FNA of thyroid nodules. 5. To study possible complications and pitfalls.Background: Ultrasound-guided FNA of thyroid nodules enables detection and characterization of cystic and solid lesions. It can be easily performed with low cost and with minimal complication rate in experienced hands. We present a teaching module of the technique in a DVD-Rom, based on our experience, and a series of educational lectures in order to facilitate training of doctors.

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Procedure Details: Individual teaching topics include fundamental principles of ultrasound physics and technology, study of thyroid anatomy and general features of benign and malignant lesions. Relevant Doppler findings and common artifacts are also discussed. Machine settings to optimize diagnostic results are noted. Transducer manipulations are described step by step through real-time video files. Correct technique is shown on simultaneous screen display of transducer positioning, and ultrasound images are captured. Features of benign and malignant lesions are outlined by retrieving archived images. A bilingual approach is followed by complementing Greek text with English subtitles.Conclusion: Ultrasound-guided FNA is very useful for the detection and differentia-tion of benign and malignant thyroid nodules. This educational DVD-Rom facilitates performance by teaching the technique, its pitfalls and possible complications.

C-519 Color Doppler sonography in hyperparathyroidism M. Squarcia, L. Buñesch, R. Gilabert, F. Calaf, M. Puig; Barcelona/ES (squarcia@clinic.ub.es)

Learning Objectives: The purposes of this study are: (1) to learn sonographic cervi-cal anatomy and ultrasound (US) scanning technique, (2) to review US features of parathyroid glands disease and (3) to illustrate the value of color Doppler ultrasound (CDUS) in the diagnosis and preoperative evaluation of hyperparathyroidism.Background: Diagnosis of hyperparathyroidism is based on clinical and biochemi-cal findings. Causes of primary hyperparathyroidism are single adenoma (80%), hyperplasia (15%), carcinoma (4%), and multiple adenoma (1%). Secondary hyperparathyroidism is due to parathyroid hyperplasia secondary to hypocalcemia. Several non-invasive imaging techniques including US,CT, MRI, and 99m Tc-sesta-mibi scintigraphy are performed to preoperatively localize parathyroid tumors and pathologic glands and therefore permit a minimally invasive surgery.Procedure Details: In this exhibit we describe:(1) the CDUS study methodology of the cervical area with emphasis on anatomic variants and pitfalls, (2) CDUS features of parathyroid glands disease. We finally propose a diagnostic imaging algorithm for the preoperative evaluation of patients with hyperparathyroidism.Conclusion: CDUS is useful in the diagnosis of hyperparathyroidism. A precise preoperative localization of the pathologic parathyroid glands permit a targeted surgical approach, thus avoiding a more extensive cervical dissection.

C-520 F-18 FDG-PET of the thyroid glands: Comparison with ultrasound findings S. Kawase1, K. Kato2, S. Ito1, A. Nishio2, M. Tadokoro3, N. Makino1, S. Naganawa2; 1Toyota/JP, 2Nagoya/JP, 3Toyoake/JP

Purpose: To compare the efficacies of F-18 fluorodeoxyglucose (FDG) uptake in the thyroid grands and ultrasound findings for the detection of thyroid cancer.Methods and Materials: A total of 1627 patients was examined by whole body FDG-PET scan for the period January 2006 to June 2007. Ninety-three patients (5.7%) of them had high FDG uptake in the thyroid glands, and 46 of these 93 patients underwent ultrasound examination. Forty-three nodules in 38 of 46 pa-tients, except those who were previously known to suffer from thyroid diseases and showed diffuse FDG uptake in the thyroid glands, were enrolled in this study. Ultrasound findings were assessed using diagnostic criteria for thyroid nodules (shape, border, and internal echoes). The threshold of FDG uptake was defined as the maximal standard uptake value (SUVmax) 4. Thyroid cancer was diagnosed by cytological and clinical follow-up.Results: Eight (19.5%) of the 43 nodules were finally diagnosed as thyroid cancer. Sensitivity, specificity and overall accuracy of ultrasound findings in detection of thyroid cancer were 100, 54.3 and 62.8%, respectively. Those of SUVmax were 50, 65.7 and 62.8%, respectively.Conclusion: This study demonstrated that the patients who had FDG uptake in the thyroid glands had the possibility of thyroid cancer regardless of the measure of SUVmax and ultrasound imaging which could be a reliable method to detect thyroid cancer. These findings suggest that all patients who have FDG uptake in the thyroid glands should receive ultrasound examination as screening test regardless of the measure of SUVmax.

C-521 Ultrasonographic patterns of parathyroid glands (PTG) in responders and non responders hemodialyzed patients with secondary hyperparathyroidism (SHPT) C. Vulpio, A. De Gaetano, A. Biscaglia, M. Bossola, G. Luciani, G. Maresca; Rome/IT

Purpose: The PTG ultrasound (US) results useful to detect number, size and different echo-structural (ESP) and blood supply (BSP) patterns correlated to ir-reversible nodular hyperplasia. This study examines the relationship between the US PTG patterns and SHPT degree and therapeutic outcome.Methods and Materials: Twenty moderate SHPT (M-SHPT: PTH 300-800 pg/ml), 20 severe SHPT (S-SHPT: PTH 800 pg/ml) and hemodialysis patients underwent US to assess number of PTG, maximum longitudinal diameter (MLD) of the larg-est PTG, and ESP (1 hypoechoic, 2 sligh heterogeneous 3 high heterogeneous, 4 nodular) and BSP (low or high vascularization). All the US PTG detected have been confirmed by TC (MIBI)-scintigraphy.Results: PTG were detectable in 75% of M-SHPT patients and in 100% of those with S-SHPT. The MLD of M-SHPT and S-SHPT was 7.2 2.3 mm and 15 5.1 mm, respectively, (p 0.001). Following 6 months of i.v. calcitriol therapy, we have ob-served 15 R and 25 NR. In NR patients PTG number resulted significantly higher than in R one (p 0.001). MLD of largest PTG results were significantly higher in NR (12.7 5.4 mm) than in R 6.5 1.5 (p 0.002). In R patients the hypoechoic or slightly heterogeneous patterns associated to low blood flow signal prevailed. Conversely in NR patients the PTG appeared greatly heterogeneous or nodular with medium and high BSS (p 0.001).Conclusion: The adopted classification of PTG US patterns resulted tightly cor-related to SHPT degree. The proposed US classification might be useful in the assessment of SHPT severity and in therapeutic decision making.

C-522 The contribution of ultrasound guided fine needle aspiration in thyroid nodules management A. Kokkinaki, N. Lepida, D. Kyriakoylis, M. Gravanis, A. Lourbakou, A. Anagnostara, S. Mylona; Athens/GR (sofimylona@yahoo.com)

Purpose: It is reported that the diagnostic accuracy of fine needle aspiration (FNA) of thyroid nodules is increased with ultrasound guidance (UG-FNA), especially in the case of non-palpable nodules. However, the use of UG-FNA in everyday practice is still controversial because of the absence of large studies as well as unawareness of the natural history of well-differentiated microcarcinomas of thyroid gland. The purpose of this study was to evaluate the role of UG-FNA in the management of thyroid nodules.Methods and Materials: We retrospectively studied 960 patients (690 women and 270 men) aged 25-70 years in whom a UG-FNA was performed. The nodules size was between 0.5-5.4 cm (mean 2.9 cm). 228 of the above patients underwent thyroid-ectomy and a comparison between histological and cytological results was made.Results: Cytological analysis revealed non-malignant lesions in 720/960 (75%), primary thyroid carcinoma in 31/960 (3.2%) (22/31 papillary, 5/31 follicular, 3/31 medullary and 1/31 anaplastic), metastatic carcinoma in 6/960 (0.7%), suspicious lesions in 75/960 (7.8%) and non-diagnostic in 128/960 (13.3%) of the cases. In the 228 cases that underwent thyroidectomy, a comparison of cytological and histologi-cal results was made. UG-FNA findings were true positive in 34, false positive in 3, true negative in 187 and false negative in 4 patients. From the 75/960 suspicious cases only two were papillary carcinomas. Sensitivity and specificity of UG-FNA was 89.5% and 98.4%, respectively.Conclusion: UG-FNA is a fast, economic and effective interventional method for the evaluation and management of thyroid nodules in every day practice.

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Head and Neck

Miscellaneous

C-523 Skull base foramina, a minefield for radiologists: What to look for on MR E. Kelliher, H. Khosa, E. Delappe, C. Cronin, P. McCarthy, C. Roche; Galway/IE (emma_kelliher@yahoo.com)

Learning Objectives: To review the anatomy of the foramina of the skull base and demonstrate these on plain radiographic CT and MR images.To provide a pictorial review of MR findings in patients with: 1) lesions of the neurovascular contents of these foramina and 2) direct (from extracranial lesions into the skull or intracranial lesion extending out of the cranial cavity) or perineural spread of neoplastic and inflamatory conditions via these foramina.Background: Interpretion of images of the skull base is a a difficult and daunting task due to the complexity of skull base anatomy. Appreciation of and accurate interpretation of abnormalities of the skull base and their contents on MR is vital because: 1) this area is difficult to assess clinically and 2) it enables early diagnosis of the existence and extension of neoplastic lesions so as to optimise patient outcome.Imaging Findings: A comprehensive pictorial review will be presented of MR find-ings in patients attending a university hospital with neurovascular lesions and soft tissue tumours of the head and neck. Emphasis is made on the key MR anatomy and sequences, which must be interrogated to evaluate these patients thoroughly.Conclusion: The reader will have geater confidence in the diagnosis and inter-pretation of skull base abnormalities on MR.

C-524 Imaging of the orbital apex and optic canal P.S. Goh; Singapore/SG (dnrgohps@nus.edu.sg)

Learning Objectives: 1) To review the anatomy of the orbital apex and optic canal. 2) To present traumatic, inflammatory, vascular and neoplastic conditions in this region to illustrate the importance of understanding the anatomy of this area.Background: The orbital apex and optic canal contain several important structures including the optic nerve. This presentation will illustrate how an appreciation of the anatomy of this area and knowledge of common pathological entities and their radiological appearance is clinically important.Imaging Findings: Diagrams as well as CT and MRI images of this region will be presented to demonstrate important anatomical relationships and the impact of several pathological entities on the optic nerve. Diagnostic features will be high-lighted to aid definitive diagnosis.Conclusion: Knowledge of the anatomical relationships of the orbital apex and optic canal as well as awareness of the impact of different pathological entities on these relationships is important in clinical practice.

C-525 Compartmental anatomy of the head and neck: What every radiologist should know H. Verma, N. Bharwani, P.L. Skippage, E. Goldstraw, S. Brown, E.J. Adam; London/UK

Learning Objectives: 1. To outline the normal anatomy of the fascial compartments of the head and neck (H&N). 2. To appreciate that knowledge of compartmental anatomy is essential for understanding the patterns of tumour propagation and the spread of infection.Background: Comprehension of the soft tissue spaces of the H&N is often chal-lenging. This pictorial review will delineate the boundaries of these compartments and illustrate their relevance to H&N pathology.Imaging Findings: CT and MRI images will be used to demonstrate the margins of the fascial compartments and their normal contents. We will discuss, with imaging examples, the common pathologies arising in each fascial compartment, how they affect the surrounding anatomy and typical pathways of spread.Conclusion: An understanding of head and neck anatomy is fundamental in reaching a reasonable and accurate differential diagnosis of pathology. This picto-rial review will illustrate normal anatomy before discussing common pathologies and patterns of disease spread.

C-526 Pitfalls in head and neck FDG PET CT: An update J.V.P. Liaw, F. Gollub, J. Chambers, W.L. Wong; London/UK (jvpliaw@hotmail.com)

Learning Objectives: 1. To review the spectrum of pitfalls in head and neck FDG PET CT. 2. To recognise and describe the atypical FDG findings.Background: Lesions in the head and neck can involve different structures and compartments, ranging from bone (skull base, mandible), bony cavity lined by mucosa (middle ear, mastoid cells, paranasal sinuses), joints (temporalmandibular joint) to soft tissue structures such as the upper aerodigestive tract, salivary glands, thyroid gland and lymph nodes. Recognition of FDG avid lesions in the head and neck which may mimic pathological conditions and the awareness of malignant lesions which may not be FDG avid is the key to making a correct diagnosis.Imaging Findings: The cases presented will include: 1. Unusual appearances of physiological uptake. 2 Benign disease which is FDG avid. 3. Malignant pathology that may not be FDG avid. 4. Post treatment appearance including those due to radiotherapy and chemotherapy 5. Atypical appearance of tumour recurrence. 5. Technical factors that mimic pathology.Conclusion: 1. Pitfalls in head and neck are frequent findings. 2. Familiarity with their appearance on FDG PET CT is important to avoid misdiagnosis and therefore potential error in treatment.

C-527 A pictorial review of cervical nodules diagnosed by ultrasound M.R. Cozcolluela, L.A. Sanz, L. Miranda, M. Martinez-Berganza, H. Sarasibar, J.M. Mellado; Tudela (Navarra)/ES

Learning Objectives: To illustrate the gamut of cervical nodules and masses diagnosed by ultrasound.Background: In the evaluation of superficial nodes, ultrasound is the first method of imaging applied. Based on images acquired during the last 10 years in the Hospital Reina Sofía (Tudela), a pictorial essay of ultrasound appearance and color Doppler imaging of cervical nodules which arise from muscle, nerve, vessels, fat, salivary glands, lymph nodes, and thyroid gland will be presented.Imaging Findings: In this poster, we describe the typical ultrasound appearances of a range of lesions in the neck. These lesions were subjected to histopathologi-cal examination. We review nodules located in nerves of the neck (schwannomas, malignant neural tumors, etc.); in the sternocleidomastoid muscle (fibromatosis colli, haematoma, etc.); in lymph nodes (inflammatory, reactive, necrotic, suppurative, granulomatous, lymphomatous, metastatic disease, etc.); in salivary gland (sialo-lithiasis, inflammatory disease, first braquial cleft cyst, lymphangioma, pleomorphic adenoma, Warthin’s tumor, carcinoma, etc.); in thyroid gland (cyst, thiroiditis, multi-nodular goiter, adenoma, papillary, follicular, medullary, anaplastic and Hurtle cell carcinomas, etc.); in vessels (glomic tumor, hemangioma, yugular thrombosis, etc.) and a miscellanea (thyroglossal duct cyst, thyroglossal duct carcinoma, branchial cleft cyst, lymphangiomas, hemorrhagic pseudocyst, lipoma, abscess, etc.).Conclusion: The purpose of this exhibit is to familiarise the reader with nodules in the neck and their ultrasonographic appearances.

C-528 Looking through the orbit A. Garcia de Vicente, M. Martinez Montalban, M. Jimenez Jurado, L. Garcia del Salto, P. Ramos Lopez, A. Marco Sanz; Alcala de Henares/ES

Learning Objectives: To describe the compartmental anatomy of the orbit and its radiological appearance in Multidetector CT (MDCT) and MR Imaging (MRI). To show the MDCT and MRI protocols used in our hospital. To learn to choose the appropriate imaging technique. To review the radiological appearance of the most frequent pathology.Background: The orbit can be divided into 4 major anatomic areas: globe, optic nerve and sheath, intraconal and extraconal area. This classification is essential when constructing differential diagnosis. The MRI has not completely supplanted CT as a unique choice for diagnostic imaging. CT is a good tool when movement or metallic foreign body compromises the MRI scans, and it improves the evalua-tion of calcification and bone.Procedure Details: We review the studies performed with MDCT and MR, cover-ing a period within January 2006 and August 2007, which were requested by the ophthalmology service upon the suspicion of orbit pathology. We illustrate the radio-logical findings including normal anatomy and inflammatory, tumoral and traumatic pathology. MDCT images were obtained using following parameters: 16x1.25 mm detector configuration; 1.375:1 pitch; 150 mAS; 120 Kv; 1.25 slice thickness. The helical data set was reconstructed at 0.625, MRP (multiplanar reconstruction plane) at axial, coronal and sagital images. MR imaging at 1.5 T with spin-echo (SE) and

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short inversion time inversion recovery (STIR) sequences and high-resolution surface-coil enhancement with contrast was used in tumor/inflammatory disease.Conclusion: Knowledge of the radiological appearance of normal and abnormal images of the orbit is mandatory for its correct characterization and differential diagnoses.

C-529 The role of imaging in facial paralysis N. Satogami, T. Koyama, Y. Miki, K. Togashi; Kyoto/JP

Learning Objectives: To review the clinical symptoms of facial paralysis according to the injured level of the facial nerve. To review the role of imaging in a wide variety of etiologies for facial paralysis.Background: Facial paralysis is caused by various etiologies, including trauma, tumor, inflammation and vascular diseases and is clinically divided into central and peripheral according to the affected segment of the facial nerve. The knowledge of detailed clinical symptoms is important because the preferred modality and scanning technique should be altered according to the suspected level of injury. The purpose of this exhibit is to discuss the role of imaging in differentiating the causes of facial paralysis, by demonstrating the CT and MRI features in various etiologies.Imaging Findings: Central paralysis is evaluated by brain MRI, which should dif-ferentiate brain tumors, demyelinating disorders, infarction, hemorrhage, AVM etc. In peripheral paralysis, injuries at the cisternal segment are caused by CP angle tumor, basal meningitis, aneurysm etc., and they are evaluated by MRI targeted for CP angle. Injuries at the intratemporal segment are caused by fracture, neurinoma, primary or secondary temporal bone tumors, cholesteatoma, neuritis, and otitis media. Most of them are evaluated by high-resolution CT targeted for temporal bone. Injuries at the extracranial segment are commonly caused by diseases in the parotid gland, including sarcoidosis and carcinomas. Facial paralysis at the neuromuscular junction is caused by myasthenia gravis, which may be associated with thymoma.Conclusion: Imaging studies can play an important role for differentiation of etiologies in facial paralysis.

C-530 Neck lymph node tuberculosis: A frequently forgotten diagnosis B. Viamonte, J. Loureiro, N.P. Silva, M. Castro, J.C. Lobo; Porto/PT (barbaraviamonte@gmail.com)

Learning Objectives: 1. Review the imaging features of neck lymph node tuber-culosis. 2. Learn the differential diagnosis of head and neck lymphadenopathy. 3. Point out imaging findings highly suggestive of neck lymph node tuberculosis.Background: Lymph node tuberculosis represents approximately 15% of cases of extrapulmonary tuberculosis, 1-2% of all new cases of tuberculosis and accounts for approximately 5% of cases of cervical lymphadenopathy.The clinical and radiologic features may mimic those of many diseases, but there are some findings that strongly suggest this diagnosis. Imaging features are varied and nonspecific, although rim enhancement or calcification, if present, can be a strong indicator of the disease. A high index of suspicion is important for early diagnosis, especially in high-risk populations. Whenever a patient with known or suspected pulmonary tuberculosis develops a head or neck lesion, a diagnosis of tuberculosis must be considered and the appropriate microbiologic studies and biopsy carried out.Imaging Findings: A didactic format will be utilized and organized based on im-aging findings and clinical features of neck lymph node tuberculosis. An overview of the characteristic findings of the main differential diagnosis, with focus on the discriminative features will follow. A comprehensive review of the findings on US, CT 64 slice scanner and MRI 1.5/3 T system of neck lymph node tuberculosis will be made.Conclusion: Recognition and understanding of the spectrum of imaging features of lymph node tuberculosis can allow early diagnosis and timely initiation of ap-propriate therapy, thereby reducing patient morbidity.

C-531 Peripheral nerve sheath tumors of head and neck: MR imaging features A.A.A. Abdel Razek, S. Samir, N. Nada; Mansoura/EG (arazek@mans.eun.eg)

Learning Objectives: To review the spectrum of peripheral nerve sheath tumors of the head and neck. To present the MR features of peripheral nerve sheath tumors in the head and neck. To illustrate MR finding suggestive of malignancy.Background: Peripheral nerve sheath tumors of the head and neck may be isolated or part of neurofibromatosis syndrome and uncommonly change to malignancy.

Imaging Findings: A retrospective reviewing of MR imaging in 80 patients with peripheral nerve sheath tumors in different regions of the head and neck was carried out. Schwanomas appeared as well-defined encapsulated masses and neurfibro-mas appeared as paraspinal in location. Multiple schwanomas are commonly seen in neurofibromatosis (NF) type II. Plexiform neurofibroma is a diffusely infiltrating mass that is associated with NF type. Malignant peripheral nerve sheath tumors appeared as large masses with heterogeneous contrast enhancement.Conclusion: MR imaging adequately diagnosed benign peripheral nerve sheath tumors, differentiating them from the malignant counterpart and suspected patients with neurofibromatosis.

C-532 16-detector row CT dacryocystography B. Marc, F. Bonnet, C. Hoeffel, G. Mac, S. Veron-Piot, A. Ducasse, C. Marcus; Reims/FR (benjaminmarc@hotmail.com)

Learning Objectives: 1. To become familiar with the technique of MDCT dacryocys-tography. 2. To understand what the questions of the surgeon are and how to assess a MDCT dacryocystography. 3. To highlight the role of multiplanar reconstructions and of virtual endoscopy in the evaluation of the nasolacrymal system.Background: Several techniques have been used to image the nasolacrymal sys-tem, providing functional (dacryoscintigraphy) or morphologic (dacryocystography, CT or MR dacryocystography) information. CT dacryocystography is a technique that provides detailed imaging of the lacrimal outflow system and surrounding structures. The information obtained from this technique is helpful in clinical and surgical decision making.Procedure Details: We present our experience of 16 detector row CT dacryocys-tography in the evaluation of patients with epiphora or repeated dacryocystitis (30 patients). Anatomy is described and our protocol is detailed. Various examples of findings obtained with this technique and correlated with surgical/pathological data are illustrated. We also highlight and discuss the role of 2D thin-slice reconstructions, of 3D reformats and of virtual endoscopy of the nasolacrymal system.Conclusion: Radiologists should become familiar with this relatively safe and well-tolerated technique which has become a reference imaging modality in the evaluation of the nasolacrymal system.

C-533 Infectious diseases of the neck: Remark on Lemierre’s syndrome A. Iñiguez Gomez, A. Litcheva Gueorguieva, N. Arevalo Galeano, E. Crespo Vallejo, J. Gredilla Molinero, A. Ruiz Ollero; Madrid/ES (assialag@excite.com)

Learning Objectives: To describe the spectrum of infectious diseases that can affect the neck. To explain the different compartments of the neck that can be affected.To illustrate the utility of imaging techniques such as ultrasound, CT and some MRI studies and to describe their indications and utilities.Background: Infectious diseases of the neck are common findings and may rep-resent a variety of conditions. Lemierre’s syndrome is an uncommon life-threaten-ing sepsis that occurs after oropharyngeal infection due to an anaerobic bacillus. Septic thrombophlebitis of the internal jugular vein with subsequent systemic dissemination may occur.Gray-scale and Doppler US, conventional and three-dimensional CT, and MR imaging have been proposed for the evaluation of such lesions, and each has its own advantages and limitations.Imaging Findings: Imaging findings are common to the rest of the infectious processes in any other part of the body. Cellulitis presents with a soft tissue mass showing marked contrast enhancement with edema and obliteration of normal fat planes. Abscesses are masses with low attenuation that show peripheral enhancing and adenitis is characterized by enlarged lymph nodes. Lemierre’s syndrome is characterized in the acute phase by the existence of an enlarged, thrombus-filled vein with loss of adjacent soft tissue planes. If systemic dissemination exists, ab-scesses in other organs including lung and brain can be observed.Conclusion: Careful attention to clinical history and physical examination findings,

along with a multimodality imaging approach, is very helpful in the diagnosis and management of infectious neck lesions.

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C-534 Head and neck paragangliomas: Comparison of contrast-enhanced 3D MR angiography and spin-echo MR imaging techniques F. Neves, L. Huwart, D. Reizine, P. Herman, E. Vicaut, J.-P. Guichard; Paris/FR (fernandoneves91@yahoo.fr)

Purpose: A rapid and accurate MR imaging (MRI) technique would be beneficial to assess paragangliomas in the head and neck and to distinguish them from other lesions. The purpose of this study was to compare the diagnostic accuracy of ellipti-cal centric contrast-enhanced MR angiography (CE MRA) with that of unenhanced and enhanced spin-echo imaging (conventional MRI).Methods and Materials: Three radiologists retrospectively and independently reviewed CE MRA and conventional MRI in 27 patients with suspected paraganglio-mas. The overall image quality and the probability of paraganglioma were recorded. The results of each modality were analyzed for sensitivity and specificity. Histological analysis, imaging and/or clinical findings served as the reference standard.Results: Forty-six lesions were found in the group of 27 patients. Sensitivity and specificity were respectively: for CE MRA, 100% and 94%; for conventional MRI, 94% and 41%. The specificity of CE MRA was significantly higher than that of conventional MRI (p=0.004). There was good to excellent interobserver agreement in the paraganglioma probability with CE MRA (nonweighted kappa, 0.67-0.77), whereas there was fair to good interobserver agreement with conventional MRI (nonweighted kappa, 0.50-0.65). CE MRA enabled to decrease acquisition time with an excellent image quality (58 sec for CE MRA versus 759 sec for the 4 spin-echo sequences).Conclusion: CE MRA was an accurate technique for assessment of head and neck paragangliomas. It suffered from fewer technical limitations than conventional MRI and provided the radiologists with added confidence in their interpretation due to superior specificity.

C-535 Ultrasound in the evaluation of diseases of the submandibular and parotid gland: Oldy but goody S. Ntai, S. Mylona, N. Lepida, A. Lourbakou, S. Patsoura, N. Batakis; Athens/GR (sofimylona@yahoo.com)

Learning Objectives: To present normal ultrasound anatomy and relations of the submandibular and parotid gland. To review the most commonly encountered clinical entities involving them and present their ultrasound characteristics.Background: The submandibular and parotid glands are affected by a number of disease processes, occasionally difficult to distinguish clinically. Their super-ficial location makes it ideal for ultrasound evaluation, and ultrasound is a useful adjunct to clinical examination. Between June 2005 and June 2007, 78 patients with symptoms and signs of salivary gland pathology were ultrasonographically evaluated in our department.Procedure Details: The diagnosis of inflammation was made depending on the character of parenchymal changes of the salivary gland: the increase of the gland with lowering of echogenicity was characteristic of acute inflammation (17 patients), whereas reduction in size and increased echogenicity were indicative of chronic inflammation (28 patients). Concomitant ultrasound features (29 patients) included enlarged leading out duct with the presence of concrement or stone-casting acoustic shadow. Three patients with Sjögren syndrome were also examined as part of a regular follow-up. In the remaining 30 patients, a suspected neoplasm was identified within the gland (26 in the parotid, 4 in the submandibular gland) and ultrasound was used to guide fine needle aspiration.Conclusion: Ultrasound must be the initial imaging tool for the evaluation of symptomatic parotid and submandibular gland, since it can provide information on the site, nature and extent of glandular pathology and guide with regard to the need for further imaging, usually with CT or MRI.

C-536 Inflammatory salivary diseases: Pictorial essay J. Pires, M. Teixeira Gomes, R. Maia, P. Santos, J. Reis; Porto/PT (jmigps@gmail.com)

Learning Objectives: To describe and illustrate the spectrum of findings in inflam-matory salivary diseases.Background: Inflammatory diseases are the most common group of diseases affecting major salivary glands. Ultrasound (US) is frequently the first method employed in the study. Sialography, computed tomography (CT) and magnetic resonance (MR) may also be used to obtain complementary information or for differential diagnosis.

Imaging Findings: Calculi can provoke duct obstruction leading to inflammation (sometimes recurrent). They are most frequent in sub-mandibular gland. Although plain film and CT can be used for diagnosis, US is nowadays a well-established method for diagnosis, identifying hyperechoic foci with posterior acoustic shad-owing. It also allows location of calculi (parenchyma/duct). Sialography remains, however, the standard technique for evaluation of the ductal system. MR sialog-raphy is a promising method that may also be used if dilated ducts are present. In acute infectious sialadenitis, US allows identification of characteristic findings (enlarged and hypoechoic gland; occasionally with inhomogeneous parenchyma or increased blood flow) and exclusion of calculus, duct dilatation or complications (such as abscess). Chronic sialadenitis is a clinically characterized entity. On US, the glands are normal sized or smaller, hypoechoic and inhomogeneous. Sialography is sometimes useful in evaluating the ductal system. Granulomatous and auto-im-mune sialadenitis are less frequent entities. US is a good technique for diagnosing parenchymal changes, biopsy guiding and follow-up.Conclusion: Inflammatory salivary pathologies are frequently encountered prob-lems. The radiologist must be familiar with them, so that he can easily recognize the main findings and give a suitable answer to the clinician.

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Interventional Radiology

Vascular

C-537 Therapeutic embolization: First choice or last resort? S.S. Hedgire, P. Gupta, J. Sathenjeri Rajendra, T. Kalyanpur, V. Ilayaraja, M. Cherian, R. Dhanpalan, R. Karwal; Coimbatore/IN (hedgire@gmail.com)

Learning Objectives: To understand the scope and limitations of therapeutic embolization.Background: Interventional radiology today is at the forefront of medical develop-ment. Its applications in diagnosis and therapy are on the increase. Therapeutic embolization is one such application wherein blood vessels are deliberately oc-cluded for therapeutic effect. The choice of hardware, embolization material and careful case selection are critical.Procedure Details: 1. Embolization materials available. 2. Emergency applications. 3. Elective applications.Conclusion: Therapeutic embolization is fast emerging as a first line treatment for various emergency situations and as an alternative treatment to open surgeries. We present the gamut of applications that is possible with this procedure.

C-538 Non-surgical management of haemorrhagic splenic injuries A. Hilario, S. Borruel, P. Martin, E. Garcia-Hidalgo, M. Chico, C. Garcia; Madrid/ES (amayahilario@yahoo.es)

Learning Objectives: To evaluate the relevance of clinical and computed tomo-graphic (CT) criteria of splenic injuries in adults. To examine the success rate of nonoperative management of blunt splenic injury. To define the benefits and risks of splenic embolization.Background: Nonoperative management of blunt splenic injuries has evolved to include patients of all ages and with all grades of splenic injury. The dominant element of the decision algorithm is the status of vital signs. Patients who present hypotensive require operative exploration. Observation, physical examination, hematocrit determinations, bed rest and limited oral intake are the most commonly used treatment strategies for conservative management. Splenic embolization has proved to be of unequivocal benefit to the majority of hemodynamically stable patients with bleeding splenic injuries.Procedure Details: During a 36-month period, all patients admitted with the diagnosis of blunt splenic injury were reviewed. Patients who were hemodynami-cally stable and require no immediate surgery underwent contrast-enhanced CT. Computed tomographic scans were assessed for splenic vascular contrast material extravasation or posttraumatic splenic vascular lesions. All patients with haemor-rhagic splenic injuries underwent arteriography. Angiographic results were analyzed including embolization technique as well as embolization material. Demographics, diagnostic evaluations, extent of abdominal injury, outcome and delayed complica-tions (infarction or splenic infection) were examined.Conclusion: Contrast-enhanced CT plays a valuable role in selecting hemo-dynamically stable patients with splenic vascular injury who may be treated with transcatheter therapy. Coil embolization of the splenic artery is an effective method of hemostasis and potentially improves the success rate of nonsurgical management.

C-539 Imaging spectrum of infrarenal endovascular abdominal aortic aneurysm repairs (EVAR) complications and its management J.V.P. Liaw, M. Clark, R. Gibbs, M.P. Jenkins, N.J.W. Cheshire, M. Hamady; London/UK (jvpliaw@hotmail.com)

Learning Objectives: 1. Review the clinical spectrum of technical and non technical complications of infrarenal EVAR. 2. Highlight the role of imaging in the diagnosis and assessment of EVAR, thus helping in the management of these patients.Background: Endovascular aortic aneurysm repair (EVAR) is now an established technique for treating many patients with infrarenal abdominal aortic aneurysm. The technique is known to have complications and understanding these is crucial for the life long performance of stent graft.Imaging Findings: 1. Clinical significance of technical and non technical aspects of endovascular aortic aneurysm repairs. 2. Plain radiography, ultrasound, CT, MRI and nuclear medicine techniques and the role of image post processing for dedicated evaluation in post EVAR stent graft. 3. Pictorial reviews of wide spectrum of technical complications (endoleaks, stent migration, stent wire fracture, graft thrombosis, graft stenosis, graft kinking, assess artery injury) and non technical

complications (graft infections, colonic ischemia, lower limb ischemia, Hemorrhage, local wound complication and renal dysfunction).Conclusion: Increased awareness of complication and knowledge of imaging appearance helps to establish accurate diagnosis, which facilitates appropriate medical or surgical management. Early diagnosis with CT and MRI avoids life threatening complications, thus decreasing morbidity and mortality.

C-540 Technical difficulties related to endovascular stenting in hybrid repair of complex thoraco-abdominal aortic aneurysms (TAAA) J. Burrill, C. Riga, J.H.N. Wolfe, M.P. Jenkins, R. Gibbs, N.J.W. Cheshire, M. Clark, M. Hamady; London/UK (radiology@burrill.demon.co.uk)

Learning Objectives: To describe the various forms of TAAA requiring hybrid repair. To discuss the technical difficulties related to endovascular stenting in hybrid repair. To discuss the lessons learnt from hybrid repair.Background: Mortality arising from open repair of TAAA is formidable. Hybrid re-pair is a recognised treatment of some TAAA utilising both open and endovascular procedures and has a reduced mortality (in this centre 13% for type I, II, and III TAAAs). Although the advent of fenestrated stents has allowed the endovascular treatment of more complex TAAA, there remains a group of aneurysms that cannot be treated with an endovascular approach alone. Endovascular stenting in hybrid repairs involves specific difficulties, which require a unique approach to planning.Procedure Details: Using case examples, we examine the planning used prior to hybrid repair: looking at difficulties relating to the proximal landing zone (angulation and arch hybrid), distal landing zone (dissections and aneurysms), side branches (early bifurcation and multiplicity) and trunk (long stented segments, sharp taper-ing, tortuosity and stent sizing). The imaging and endovascular strategies of such cases are shown and discussed.Conclusion: Hybrid repair for complex TAAA remains a solution where endovas-cular treatment is not possible, as the sole modality, and has reduced mortality and morbidity compared to open repair alone. Knowledge of the difficulties related to the endovascular process allows proper planning, reducing the risks of complications and improving long-term durability.

C-541 Vascular and nonvascular interventions in pancreatitis S. Subramanian, S. Gamanagatti, D.N. Srivastava, Z. Abbas, P. Garg; New Delhi/IN (drsubbusmc@yahoo.co.in)

Learning Objectives: To illustrate the role of various interventions in managing patients with complications of acute pancreatitis.Background: Acute pancreatitis can lead to various complications like pancreatic necrosis, abscess, and pseudocyst formation. In addition, pseudo aneurysm may develop, which may bleed into the pseudocyst or cause gastrointestinal bleed. Management of these patients is challenging and intervention radiology has an important role in these patients.Procedure Details: Vascular complications: Vascular complications of pancreatitis include pseudo aneurysm formation in splenic artery, gastro-duodenal artery and small pancreatic branches and hemorrhage into the pseudocyst due to arterial rupture. Pseudoaneurysms can be managed successfully by embolisation either by endovascular or percutaneous route. Nonvascular complications: Pseudocyst can be drained percutaneously using 8-12 F catheters with a high success rate. Infected pseudocyst, pancreatic abscess and pancreatic necrosis require large-bore catheter, 12-16 F, for drainage and the success rate is variable. For multiple abscesses, more than one catheter is required for adequate drainage. CT guidance is preferred for percutaneous drainage. Left anterior pararenal approach is used for draining collection from the tail of pancreas and gastrocolic ligament approach for collection from head and body.Conclusion: Vascular and nonvascular complications of pancreatitis can be man-aged successfully by the interventional radiologist.

C-542 Percutaneous management of aggressive vertebral haemangiomas: How, when and why? X. Buy, T. Moser, J.-L. Dietemann, A. Gangi; Strasbourg/FR (xavier.buy@chru-strasbourg.fr)

Learning Objectives: To provide guidelines for percutaneous management of aggressive vertebral haemangiomas (AVH). To describe the different therapeutic modalities, their indications and when to combine them, based on our experience of 33 cases in 31 patients.

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Background: AVH represent less than 1% of vertebral haemangiomas. They are characterized by a small fatty component and a large vascular component. The vascular density of these benign malformations is directly correlated with the clinical symptoms (pain, neurological compression), the imaging features and the potential for increase. By contrast with non-evolutive fatty haemangiomas, AVH require systematic treatment.The therapeutic options are surgery, radiotherapy, arterial embolization, sclerotherapy and vertebroplasty. The techniques, indications and combinations are described and illustrated.Procedure Details: Vertebroplasty is the therapeutic mainstay as it allows direct vascular embolization and vertebral consolidation. Sclerotherapy is combined with vertebroplasty for occlusion of the epidural and paravertebral components of the haemangioma. Systematic use of high-dose methyl prednisolone during and after sclerotherapy for epidural extension is necessary to avoid neurological complications. The role of surgery is limited to laminectomy in cases of evolving neurological deficit, post percutaneous treatment. Radiotherapy is less commonly indicated since the development of other techniques.Conclusion: Management of AVH requires collaboration between spine surgeons and interventional radiologists. AVH limited to the vertebral body should be treated by vertebroplasty only. For more complex lesions with paravertebral or epidural extension, combined therapies (sclerotherapy, vertebroplasty sometimes associ-ated with arterial embolization or laminectomy) are necessary to achieve complete obliteration of this vascular malformation to ensure vertebral consolidation and neurological decompression.

C-543 Diagnosis and interventional radiology for renovascular disorders D. Uchiyama, M. Koganemaru, T. Abe, R. Iwamoto, S. Yoshida, N. Hayabuchi; Kurume/JP (uchiyama_daiji@kurume-u.ac.jp)

Learning Objectives: To illustrate the characteristic findings of CT, MRI, and angiography of renovascular disorders. To outline the indication, efficacy, and safety of interventional radiology. To describe the results, limits, and follow-up us-ing interventional radiology.Background: Interventional radiology (IVR) for renovascular disorders is an ef-fective method compared to surgery because IVR contributes to the preservation of renal function. In this exhibit, we will describe the use of various modality and IVR in renovascular disorders with characteristic findings, suitable indications, the results, efficacy, safety, and limits.Procedure Details: We will describe a series of 8 renovascular disorders: renal artery aneurysm, renal artery pseudoaneurysm, renal arteriovenous malformation, renal artery stenosis, renal artery infarction, collagen vascular disorders, isolated renal artery dissection, and nutcracker syndrome. We will describe clinical find-ings, diagnostic imaging, IVR management, follow-up management, and outcomes (including complications).Conclusion: IVR for renovascular disorders with various catheters and suitable embolic materials is safe and contributes to the preservation of renal function. We should also understand the characteristic and clinical findings for renovascular disorders.

C-544 Initial experience with the Amplatzer® vascular plug for various hepatic pathologies K.I. Ringe, H. Rosenthal, M. Galanski; Hannover/DE (ringe.kristina@mh-hannover.de)

Learning Objectives: To introduce the use of the Amplatzer® Vascular Plug (AVP) for various hepatic pathologies, especially preoperative portal vein embolization (PPVE).Background: The AVP is a device originally intended for arterial and venous embo-lizations in peripheral vessels. Indications have been mostly limited to embolizations of peripheral vessels or use in the cardio-pulmonary system. From September 2004 to March 2007, we implanted 12 AVPs in particular portal locations in 6 patients. Indications included closure of an intrahepatic shunt (n=1), PPVE (n=4) and closure of a TIPS. In 5 additional patients undergoing TIPS implantation, we performed simultaneous placement of an AVP for closure of varices.Procedure Details: In patients undergoing PPVE, the AVPs were implanted via a transcutaneous, transhepatic approach and direct puncture of the portal vein. Initially, polyvinyl alcohol particles were injected into the target vessels in order to reduce flow and embolize small branches in the periphery. In the other patients the access was through the right jugular vein. After catheter placement the AVP was advanced into the target vessel and position was verified by test injection of contrast media. The self-expanding plug was then released. Plug placement and vessel occlusion was confirmed by CT and Doppler ultrasound.

Conclusion: AVP implantation was successful in all patients. Major complications did not occur. The AVP is a versatile device which is easy to apply and, if needed, repositioning or additional plug placement is possible. Our experience shows that the AVP also can be used safely for embolizations of different hepatic pathologies.

C-545 Selective internal carotid digital subtraction angiography (DSA) for preoperative investigation of epilepsy with the Wada test A. Karatasiou, M. Karigiannis, E. Theodoropoulos, G. Karydas, C. Baltas; Athens/GR (angkaratas@yahoo.gr)

Learning Objectives: To illustrate the role of cerebral angiography in epileptic patients undergoing the Wada test for preoperative assessment.Background: The Wada test determines lateralized distribution of language and memory functions prior to surgical resection of the temporal lobe in epileptic pa-tients. It ensures that the neurosurgeon will spare the dominant hemisphere and will operate on the true epileptogenic zone. Each hemisphere is anesthetized by separate injections of amobarbital in the internal carotid arteries. Language and memory testing is performed by a neurologist in the angio suite and hemisphere dominance is determined.Procedure Details: The purpose of DSA is to depict anatomic variations such as a persistent trigeminal artery, filling of both the anterior cerebral arteries from one side or filling of the posterior cerebral artery through the posterior communicating artery. The Wada test cannot be performed in such cases in fear of anesthetizing the brain stem or the contralateral hemisphere. In our institution, 9 patients were examined in the last 2 years. All angiographies were free of complications. One patient presented a trigeminal artery variation and the procedure was terminated. Of the remaining 8 patients, 4 proceeded to surgery and no case of language or memory impairment was reported. Two of the patients remained seizure free while the other two exhibited a 50-90% improvement.Conclusion: Cerebral angiography is essential before administration of amobarbital in order to ensure a successful procedure. When in the hands of an experienced neuroradiologist, the procedure poses no threat to the patient.

C-546 Postpartum hemorrhage: Influence of angiographic findings on embolic material Y. Fargeaudou, O. Le Dref, P. Soyer, M. Boudiaf, H. Dahan, R. Rymer; Paris/FR (yannfargeaudou4@hotmail.com)

Learning Objectives: To illustrate the spectrum of vascular lesions accountable for severe postpartum hemorrhage. To identify the most appropriate embolic material according to the observed lesion. To describe the collateral pathway that could maintain the bleeding.Background: Although pelvic arterial embolization has become the favored treat-ment for postpartum hemorrhage, this condition is still the main cause of maternal death related to pregnancy in Western countries. Uterine atony, cervicovaginal lacerations and abnormal placentation are the most frequent causes of postpartum hemorrhage, which should be readily recognized so that the most appropriate embolic material could be used.Procedure Details: The choice of the most appropriate embolic agent depends on the location and the nature of the lesion. In case of uterine atony, occlusion of the uterine arteries with resorbable material showed safety and efficiency. In case of retained placental tissue, microparticules should be used in association with gelatin sponge. In case of active bleeding with extravasation of contrast material or pseudoaneurysm formation, metallic coils should be considered. Also, in case of persisting bleeding after uterine artery ligation, knowledge of potential collateral routes such as lumbar arteries, artery of the round ligament or ovarian artery is critical to perform an efficient embolization.Conclusion: Knowledge of pelvic arterial anatomy and recognition of the exact cause of bleeding should lead to an efficient endovascular treatment for severe postpartum hemorrhage.

C-547 An improved superselective insertion “hook back” technique of microguidewire M. Gibo, S. Unten, A. Yogi, S. Murayama; Okinawa/JP (zf-1@umin.ac.jp)

Learning Objectives: To illustrate the indications for using “hook back” technique in angiography. To describe our experiences and clinical data with this technique.Background: Superselective catheterization of microcatheter is a valuable tech-nique for vascular interventional radiology, and deep insertion technique of microgu-idewire plays a key role. Peculiar to this technique described herein is dependence upon a withdrawal motion to enter the microguidewire within target vessels.

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Procedure Details: Anatomical acute angle of small branch artery can create problems when trying to selectively insert a microguidewire. In these difficult cases, the operator usually reshapes the tip of the microguidewire as strongly single-curved or double-curved configuration. However, in many cases the microguidewire may drop back into the access vessels. We have developed an improved “hook back” technique that allows us to overcome this problem. Initially we shape the tip of the microguidewire as reversed, double-angled configuration like Simmons’s catheter. The microguidewire is advanced over the branching point of the target vessel and the loop of the microguidewire is formed by further pushing the microguidewire peripherally. When the microguidewire is drawn back, the tip of the microguidewire hooks and enters into the target artery deeply enough to slide the microcatheter over its microguidewire.Conclusion: In our clinical experience, this “hook back” technique is thought to be reliable for achieving superselective microcatheter cannulation in sharply angled small-caliber arteries.

C-548 Therapeutic implication of pre-operative embolization in high-flow AV malformation in the head and neck region C. Mohan, P.S. Bhandari, B. Batra, A. Agarwal; New Delhi/IN (bipinbatra@rediffmail.com)

Background: The therapeutic implication of pre-operative embolization in high-flow AV malformation of the head and neck region was studied. A total of 30 consecutive patients with high-flow AVM of the head and neck region were treated at the RR Army Hospital during the period from December 2001 to October 2004. The study group comprised 12 male and 18 female patients (M: F, 1:1.5) ranging from 5 to 56 years of age. AVMs involved the middle face in 80%, scalp (6.6%), lower lip (6.6%) and neck (6.6%). All AVMs were evaluated by color Doppler and MRI. CT was performed in two patients with intraosseous malformation (mandible and zygoma, one case each). All these cases were subjected to selective (55%) or super-selective (25%) pre-operative embolization, and in 20% a percutanoeus embolization approach was used. The em-bolization material used in 80% of the cases was polyvinyl alcohol (PVA) and n-butyl cyanoacrylate (n-BCA) in 20%. In 80% of the cases, 90-100% devascularization was achieved and the regions were resected within 24-48 h of embolization.Procedure Details: Postembolization arteriogram showed that 76% of the lesions were completely devascularized, five cases were effectively devasuclarized ( 90%) and ( 70%) devascularization was achieved in two cases. All these regions were resected without any significant blood loss. There was no embolization-related compli-cation with use of PVA, two lip lesions treated with n-BCA developed local thermogenic reaction. Complete resection of lesion was possible in 28/30 cases. The postoperative results were plasia with improvement in cyanosis and function. No recurrence was observed during a follow-up period of 2-1/2 to 6 years in 28 patients.Conclusion: Preoperative embolization favorably alters the outcome of the im-mediate and long-term result in high-flow AV malformation.

C-549 The IVC: Diagnostic imaging and interventional therapies C. Shaw, D.T. Murphy, J.M. Moriarty, L.P. Lawler; Dublin/IE (colshaw@iol.ie)

Learning Objectives: 1. Review normal and variant IVC anatomy and its impli-cations for imaging and treatment. 2. Review the range of diagnostic modalities available for IVC imaging including sonography, angiography, CTV, MRV and CT-PET, and design an algorithm for patient evaluation. 3. Discuss changing in-terventional approaches to IVC filters and IVC recanalisation in a range of benign and malignant conditions.Background: The IVC is central to a range of conditions that routinely affect patients in clinical practice, but frequently present late and can lead to significant morbidity and mortality. Diagnostic imaging of the IVC is often more challenging than the arte-rial system due to its thin-walled, capacious low flow state. It is a vascular system that offers little options for surgical therapy and is frequently referred to radiology for interventional endovascular management.Imaging Findings: A series of cases acquired retrospectively, presenting with symptoms of IVC obstruction, were reviewed. They included endoluminal obstruc-tion due to benign or malignant thrombus, compression or mural invasion by an extrinsic tumour mass and obstruction due to retroperitoneal fibrosis. Interventional therapies included percutaneous placement of IVC filters, mechanical and chemical thrombolysis, balloon angioplasty and percutaneous insertion of self-expanding and balloon-mounted stents.Conclusion: The IVC is a frequently forgotten vessel in vascular imaging, but nev-ertheless is central to a range of common and serious disease states. Conventional angiography has been increasingly superseded by non-invasive cross-sectional imaging for initial diagnostic evaluation and advancing endovascular techniques are offering novel options for therapeutic intervention.

C-550 Complications after hepatic artery embolization for hepatic tumors J.P. Singh, N. Kandasamy, R. Harganani, A. Goode, D. Yu, N. Woodward; London/UK (drjpsinghuk@hotmail.com)

Learning Objectives: 1. To list and identify the key imaging features of the main complications of transarterial embolization for hepatic tumors. 2. To discuss the pathophysiology and risk factors of these complications.Background: 1. Indications of hepatic artery embolisation. 2. Embolization tech-nique including transarterial Chemoembolisation (TACE).Imaging Findings: Imaging findings in complications: a) relating to target embolisa-tion - abscess formation; spontaneous rupture of tumor. b) From non-target emboli-sation - biliary; gastric. c) Hepatic decompensation - post-embolisation syndrome; hepatic insufficiency. d) Flare up of carcinoid symptoms in neuroendocrine patients. e) Complications from catheter /wire - hepatic artery dissection.Conclusion: The major teaching points of this exhibit are: 1. Hepatic artery emboli-sation is a relatively safe, widely accepted and effective way of palliative treatment. 2. Lower morbidity can be achieved by appropriate patient selection.

C-551 Role of the interventional radiologist in the management of acute lower gastrointestinal bleeding M. Barrufet Solé1, J. Sánchez Alipio2, J. Fadlala3, A. Mainar Turón1, J. Medrano Peña1, M. de Gregorio Ariza1; 1Zaragoza/ES, 2Neuquén Capital/AR, 3Rosario/AR (martabarru@gmail.com)

Learning Objectives: To illustrate the role of angiography in the localization and treatment of acute lower gastrointestinal bleeding. To discuss the feasibility, efficacy of hemostasis, recurrent bleeding, and ischemia resulting from superselective embolization based on a series of 23 patients.Background: Acute gastrointestinal bleeding is a common cause of hospitalization, morbidity and mortality and is a potentially life-threatening condition. Although most cases can be managed medically, 10-15% require intervention to control hemor-rhage. In these exhibits, we will describe the role of angiography in the localization of the bleeding point and the use of micro coil embolization for the treatment of lower gastrointestinal hemorrhage.Procedure Details: All patients underwent a diagnostic digital subtraction angiogra-phy. Celiac, superior and inferior mesenteric arteries were selectively catheterized. Embolization was performed only if the bleeding site could be identified. The major indication was treatments of massive gastrointestinal bleeding that did not respond to conservative management.Conclusion: Immediate hemostasis was achieved in 79% of patients. Superselec-tive transcatheter embolization is an effective and safe modality for the treatment of acute gastrointestinal bleeding. This treatment is not associated with significant clinical ischemia or infartion.

C-552 A fifteen years TIPS experience: Retrospective review of clinical involvements and technical aspects G. Bartoli, C. Gazzera, L. Luberto, P. Campanino, A. Doriguzzi Breatta, D. Righi, A. Ottobrelli, G. Gandini; Turin/IT (germanab@infinito.it)

Purpose: Audit of management of liver cirrhosis using TIPS.Methods and Materials: Between 1992 and 2006 we performed 658 TIPS for fol-lowing conditions: digestive-tract bleeding (48%), refractory ascitis (34%), portal thrombosis (5%), preserving portal supply in pre-OLT (4%) and thrombosis of the hepatic veins (3%). Other conditions (6%) were pleural ascitis, hepatorenal and hepatic-pulmonary syndrome. All the patients were evaluated with eco-color-Doppler (CT in 7% of the cases) and portal access was US guided. Palmaz, Memotherm, Wallstent and Luminexx stents (mean expansion 10 mm) were employed. Emboli-zation of persistent varices was performed in 6.8% of the cases.Results: The technical success rate was 99% and early stent thrombosis (within 48 hours) occurred in 11% of the cases. Twelve month follow-up showed primary and assisted patency of the shunt of 71 and 98%, respectively. Technical complications were: heart failure (6), hemobilia (6), stent mobilization (6), intrahepatic hematoma (2) and peritoneal hemorrhage (1). Eight patients with severe portal-systemic encephalopathy (PSE) were treated with a reduction stent. In 37 patients with refractory ascitis and bleeding varices, the PSE completely resolved after TIPS. The mortality rate at 12 months was 26.5%.Conclusion: The study suggests that TIPS is safe and effective. Ultrasonography plays a major role in preliminary evaluation, portal puncture and follow-up. The patency of bare stents is satisfactory; optimal assisted patency is achieved with careful surveillance. Resolution of PSE after TIPS can be explained by the reduction of either blood proteins absorption or diuretic dosage. Hepatic failure was the main cause of mortality.

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C-553 IVC-SVC filters: A comprehensive review of the spectrum of complications J. Tisnado, M.K. Sydnor, D.J. Komorowski, D.A. Leung; Richmond, VA/US (jaimetis@aol.com)

Purpose: About 4000 filters (all kinds) have been placed by us in the IVC and SVC during the last three decades. Therefore, we have accumulated a vast experience in filter placement and have seen or experienced all types of complications of the procedures.Methods and Materials: We hereby attempt to classify the spectrum of compli-cations of filter placement: (A) Vascular access: bleeding, hematoma, rupture, pneumothorax; (B) Placement: misplacement in different sites such as iliac veins, renal veins, hepatic veins, aorta, extravascular in the retroperitoneum, failure to open, embolization into right atrium, right ventricle, PA; (C) Complications: migration, rupture of prongs, “collapse,” embolization; (D) Injuries to IVC-SVC: perforation, thrombosis, stenosis, rupture; (E) Multiple insertions: 1, 2, 3 filters needed because misplacement, embolization, recurrent pulmonary embolism; and (F) Iatrogenic: rupture, extrusion, tilting, etc.Results: We describe some of the ways or methods to avoid complications and to solve them once they occur.Conclusion: Filter placement in the IVC-SVC has become a “routine” procedure. Some operators with minimal experience are placing filters. We discuss ways to avoid complications and solve problems.

C-554 Arterial embolization for controlling traumatic pelvic hemorrhage: A rapid and effective technique and review of associated literatures H.-Y. Chen, Y.-F. Chen, J.-H. Chen, K.Y. Chen, H.-J. Chiang, W.-C. Shen; Taichung/CN (ellen0225@yahoo.com.tw)

Purpose: This study aims to evaluate the efficacy of transcatheter arterial emboliza-tion in controlling arterial hemorrhage associated with pelvic trauma.Methods and Materials: In a period of three and a half years, 40 hemodynami-cally unstable patients with traumatic pelvic hemorrhage, who underwent pelvic angiography and transcatheter embolization, were reviewed retrospectively. All angiographic procedures were performed by three experienced interventional radiologists. Reasons for embolization were direct signs of vascular injury, such as contrast extravasation, pseudoaneurysm or indirect signs like vasospasm, and vessel tortuosity. Embolization agents included Gelfoam or steel coils or both. Post-embolization angiography was obtained to evaluate hemostasis.Results: Forty patients underwent pelvic angiography. Arterial hemorrhage was diagnosed initially on 36 (90%) patients requiring embolization, of whom 31 were found to have active contrast extravasation, and 5 were found to have indirect signs of vascular injury. Twenty-four patients had bleeding sites in either left (N=11) or right (N=13) internal iliac artery, 12 had bleeding sites in bilateral internal iliac arter-ies and 2 had bleeding sites in external iliac artery. Thirty-one patients have more than two bleeding sites. Eight patients underwent repeated pelvic angiogram for suspected recurrent pelvic arterial hemorrhage during the same admission. Four (11.1%) of these embolized patients required repeat angiography and emboliza-tion. The successful rate of embolization was 94.4%. There were no complications directly associated with the embolization procedures.Conclusion: Transcatheter embolization is a safe and effective method for control-ling pelvic hemorrhage in patients with hemodynamic unstable or multiple pelvic fractures.

C-555 Use of a non-adhesive liquid embolic agent in the treatment of thoracic type II endoleaks M. Corona, F. Fanelli, G. Orgera, E. Boatta, A. Pucci, M. Allegritti, P. Nardis, A. Bruni, R. Passariello; Rome/IT (m.corona@inwind.it)

Purpose: To report our experience in percutaneous treatment of type II endoleaks, after thoracic stent-graft, in type B dissections patients, using ONIX.Methods and Materials: Five patients underwent an endovascular treatment for type B dissection. Due to a short proximal neck ( 2 cm), the origin of the left subclavian artery (LSA) was covered by the stent-graft. During the follow-up, a type II endoleak originating from the LSA occurred. Through a left brachial access, the origin of the LSA was occluded with injections of 2 to 6 cc of Onyx-34 (Micro Therapeutics Inc., Irvine, CA, USA) via a micro-catheter. In one case, to reduce the blood flow during Onyx injection, occlusion of false lumen was performed using an occlusion balloon. In other two cases, Onyx was injected after coils insertion into the false lumen. Onyx is a non-adhesive, liquid, embolic agent composed of EVOH (ethylene vinyl alcohol), copolymer dissolved in DMSO (dimethyl sulfoxide), and suspended micronized tantalum powder to provide contrast for visualization.

Results: The endoleak sealed immediately in all cases, with complete exclusion of false lumen. No complications occurred during or after Onyx injection. After a mean follow-up of 16.5 months, all patients are in good clinical conditions with no endoleaks at CT-angiography. In two cases, a complete thrombosis of the false lumen occurred after one and four months.Conclusion: Onyx seams to be a safe tool in the percutaneous treatment of thoracic endoleaks. It could also be considered useful to facilitate the complete thrombosis of the false lumen.

C-556 Retrospective study of proximal vs. distal splenic artery embolization in 73 consecutive cases P.R. Rau, N.-H. Stauffer, A. Denys; Lausanne/CH (philipp.rau@gmail.com)

Purpose: Proximal splenic artery embolization (SAE) is supposed to be better tolerated by patients as compared to standard distal or segmental embolization, nevertheless fulfilling the same clinical objectives. A smaller post-interventional complication rate in terms of infarction and infection is advocated. It was thus our objective to test this hypothesis in our study.Methods and Materials: 73 consecutive patients undergoing proximal vs. distal or segmental SAE over a time period of 5 years were included in this study. Age, sex, and clinical history leading to SAE were noted. Pre-interventional imaging was reviewed for each patient, and grade of splenic injury and degree of hemoperito-neum were noted as well as the type of SAE in the following intervention. Finally, we checked all digitally available patient records for clinical and radiological (CT und ultrasound) follow-up in order to assess post-interventional complications. These were noted on a four point scale, from 0=none to 3=important complications.Results: Complications following proximal SAE (N=11, median=1.0, mean=0.64) did not differ significantly from distal SAE (N=62, median=1.0, mean=0.87), U=303.0, p=0.30, r=-0.07.Conclusion: Proximal SAE is a safe and efficacious intervention as compared to distal and segmental SAE. Interventional outcome is comparable, nonetheless with a slight tendency in favour of the proximal SAE group, without an elevated secondary splenectomy rate. Minor complications such as post-interventional splenic infarction did not show significant difference in both groups. These results allow us to pursue a prospective study which might reveal a significant advantage in favour of proximal SAE.

C-557 Vascular complications of pediatric liver transplantation: Role of interventional radiology R. Nani, R. Agazzi; Bergamo/IT (rnani@tiscali.it)

Purpose: Vascular complications of pediatric liver transplantation occurs in up to 20% of cases. We report our experience.Methods and Materials: We evaluated 30 children with vascular complications after liver transplantation: 17 hepatic artery complications (8 thrombosis, 7 ste-nosis, 1 dissection with pseudoaneurisma, and 1 pseudoaneurisma with fistula in the anastomotic loop), 6 portal vein complications, 6 venous out-flow, and 1 recurring gastrointestinal haemorrhage. Hepatic artery thrombosis were treated with thrombolysis; stenosis were treated with PTA and stent. One patient with pseudoaneurisma required rapid hepatic artery embolization. Portal vein thrombosis was treated with medical therapy in 3 cases and PTA/stenting in one case. Portal vein stenosis underwent percutaneous venoplasty. Vena cava and hepatic veins steno-occlusions were treated with PTA and recanalization in 5 cases. TIPS was performed on a IP jejunal haemorrhage.Results: Technical success was obtained in 3/5 (60%) of cases after stenting in artery stenosis; portal steno-occlusions were treated successfully with venoplasty in 2/3 cases; and one case treated with PTA and stent required a meso-caval shunt because of early occlusion. 5/6 cases of venous out-flow steno-occlusions were treated successfully with PTA. TIPS was performed successfully on a child of 20 months after split II-III and intestinal haemorrhage.Conclusion: Interventional radiology has an important role in the treatment of vascular complications of pediatric liver transplantation. Indications for the treatment of such complications, previously limited by patient’s little dimensions and difficult anatomy, are enlarged by availability of new materials.

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C-558 Complete tumor response after TACE: A selection criteria for liver transplantation in HCC patients exceeding Milan criteria I. Bargellini, V. Vallini, P. Petruzzi, P. De Simone, R. Cioni, C. Vignali, C. Bartolozzi; Pisa/IT (irenebargellini@hotmail.com)

Purpose: To retrospectively evaluate long-term clinical results of patients with hepatocellular carcinoma (HCC) exceeding Milan selection criteria who received transarterial chemoembolization (TACE) before liver transplantation (LT).Methods and Materials: From 1997 to 2006, 48 HCC patients (M:F=46:2, mean age 54.5 years) who did not fulfill the Milan selection criteria (1-10 tumor nodules, 6-100 mm axial diameter) underwent LT 6-381 days (mean 129 days) after TACE. Tumor response to TACE was evaluated at 1-month CT follow-up according to three different criteria: 1) WHO-modified criteria, 2) tumor downstaging, and 3) viable tumor volume reduction rate. Post-LT HCC recurrence and survival rates were as-sessed and analysed in relation to the tumor response to TACE.Results: At a mean follow-up of 49 months (range 1-117), 11 cases of tumor recurrence were observed. The post-LT 5-year cumulative survival and recur-rence-free survival rates were 77.3 and 69%, respectively. CT follow-up at 1 month was available in 33/48 patients (68.7%). At CT, complete response (CR), partial response (PR), stable disease (SD) and progressive disease (PD) rates were 51.5, 33.3, 15.2 and 0%, respectively. Tumor downstaging was obtained in 27/33 (81.8%) patients and the mean viable tumor volume reduction rate was 88%. The 5-year recurrence-free survival was significantly associated (P=.003) with tumor response to TACE according to WHO-modified criteria (93.3, 53.3 and 30% in CR, SD and PR, respectively).Conclusion: In patients exceeding Milan criteria, CR 1 month after TACE assessed at CT is associated with high recurrence-free survival rates after LT, regardless of tumor nodules size and number.

C-559 Interventional management of chronic pulmonary hypertension as the result of thromboembolic disease M. Barrufet Solé1, J. Sánchez Alipio2, R. Domene Moros1, J. Bosch1, A. Mainar Turón1, J. Medrano Peña1, M. de Gregorio Ariza1; 1Zaragoza/ES, 2Neuquén Capital/AR (martabarru@gmail.com)

Purpose: Pulmonary endarterectomy is the definitive treatment for chronic pulmo-nary hypertension as the result of thromboembolic disease, but not all patients are eligible for surgery. The purpose of this study is to assess the efficacy of minimally invasive endovascular techniques (angioplasty and stenting) when there is no surgical indication or the patient rejects the surgery.Methods and Materials: Eight patients with a mean age of 82.6 years and chronic pulmonary hypertension as the result of thromboembolic disease were treated at our institution. New York Heart Association (NYHA) class distribution was 6 class III and 2 class IV patients, respectively; and mean pulmonary artery pressure and pulmonary capillary wedge pressure were above 40 mmHg and below 15 mmHg, respectively. All patients underwent Doppler echocardiography, ventilation-perfusion scanning, CT angiography and pulmonary angiography. Intra-pulmonary arterial thrombolysis and angioplasty were carried out in all cases, followed by stent placement in three of them. Follow-up was made by Doppler echocardiography and ventilation-perfusion scanning at 1, 3, 6 and 12 months.Results: Technical success was achieved in all patients (100%). The average follow-up was 18.7 months. At follow-up, mean pulmonary artery pressure values on Doppler echocardiography were 24 mm Hg (p 0.005) and 85% of patients were in NYHA class I or II. One patient died of unknown causes 24 h after the procedure (12.5%).Conclusion: Minimally invasive endovascular techniques could contribute to an improvement of chronic pulmonary hypertension as the result of thromboembolic disease non treatable by surgery or drugs.

C-560 The Günther Tulip retrievable filter: Effectiveness and complications in temporary and permanent use N. Abe, R. Shuto, R. Takaji, S. Yotsumoto, Y. Sagara, N. Hongo, H. Kiyosue, H. Mori; Yufu/JP (abe1262@oka-hp.com)

Purpose: To evaluate the effectiveness and complications in temporary and per-manent use of the Günther Tulip retrievable filter.Methods and Materials: One hundred-six patients (38 men, 68 women; mean age 64.5 years) who performed retrievable Günter Tulip filters (William Cook) filtration in our institution from July 2001 to June 2007 were retrospectively reviewed. The indications for placement included pulmonary embolism (PE) (n=44), deep venous

thrombosis (n=59), and others (n=3). Patients included 63 cases intended to place permanently (permanent group) and 43 cases temporarily (temporary group). We investigated the success rates of placement and retrieval, occurrence of PE, and complications in both groups.Results: IVC filter were successfully placed without any complication in all patients. No PE has occurred following IVC filtration. In 18 patients of temporary group, the additional techniques (replacement n=5, reposition n=13) were performed to prolong retrievable time, and 3 complications (filter migration, vertebral artery injury, and retroperitoneal hematoma) occurred. In 11 of temporary group, retrieval procedure was not performed because of failure of the additional techniques (n=2), and residual thrombi despite thrombolitic/anticoagulant treatments (n=9). In the remaining 32 cases of temporary group, 30 cases (94%) were successfully retrieved. Three asymptomatic complications of minor penetration of IVC were observed in permanent group.Conclusion: Günther IVC filter can be successfully placed and prevent PE in all cases, and retrieved in most cases. However, the use of additional techniques to prolong retrievable time was associated with higher risk of complications. The indica-tions for retrieval and replacement/reposition should be carefully considered.

C-561 Accuracy of bilateral inferior petrosal sinus sampling in Cushing’s syndrome E. Granell, C. Castaño, F. Plancarte, C. García, C. Ovejero, M. de Juan, S. Valverde; Barcelona/ES

Purpose: To review the technique of Bilateral Inferior Petrosal Sinus Sampling (BIPSS) evaluating its accuracy in diagnosis of ACTH dependent Cushing’s syndrome and its capacity in predicting lateralization of the tumor when of hy-pophyseal origin.Methods and Materials: We reviewed clinical records and BIPSS of 40 patients (8 men and 32 women) aged between 17 and 70 years (mean: 37) from 1989. First, we obtained two basal samples of both inferior sinus and after an injection of 100 ug of oCRH, 3, 6 and 10 minutes later. We considered positive to determine hypophyseal origin a basal ratio of 2 and, after stimulation with oCRH, a ratio of 3. In order to discriminate lateralization, a differential ratio of 1.4 was valued between both sinuses.Results: BIPSS had a sensitivity and specificity of 100% to establish the hypophy-seal origin (33 cases) or ectopic (5 cases). The capacity of BIPSS in predicting lateralization of the tumor was 58%. We did not have complications during the procedures.Conclusion: BIPSS in ACTH dependent Cushing’s syndrome is considered an indispensable and safe tool to discriminate its origin (ectopic or hypophyseal). The interpetrosal ACTH gradient is useful to determine lateralization of the tumor, in spite of not existing in all the patients.

C-562 The possibility of the penetration injury on carotid artery and internal jugular vein during cervical transforaminal epidural injection: An analysis of 594 injections H.-S. Kim, D.-J. Chung, S.-H. Lee, S.-H. Lee; Seoul/KR (jradikim@empal.com)

Purpose: We would like to analyze the relation of the vessels and the needle route during injection and report the possibility of the injury on carotid artery and internal jugular vein.Methods and Materials: From Apr. 2005 to Aug. 2007, we performed cervical transforaminal epidural injection in 430 patients with 594 levels (18 cases in C3-4, 62 cases in C4-5, 275 cases in C5-6, 217 cases in C6-7 and 22 cases in C7-T1) under CT-fluoroscopy guidance. We reviewed CT and/or MR scan of the patients and divided into three groups (positive, borderline and negative) according to the relation between the vessels and the route of the needle from skin to the neural foramen. ‘Positive’ meant vessels were located within the route of the needle, ‘nega-tive’ meant vessels were located 5 mm or more far from the tract, and ‘borderline’ was between them.Results: 311 cases (52.4%) were positive (100% in C3-4, 89% in C4-5, 67% in C5-6, 24% in C6-7, 0 in C7-T1), 87 cases (14.6%) were borderline cases to the internal jugular vein. Among them, there were 81 cases (13.6%) of positive (83% in C3-4, 44% in C4-5, 13% in C5-6, 1.3% in C6-7) and 27 cases (4.5%) of borderline to carotid artery. 67% (398/594) of the cases would be the risk group to internal jugular vein and 18.2% (108/594) to carotid artery.Conclusion: We found that cervical transforaminal epidural injection had high possi-bility of injury on carotid artery/internal jugular vein (67 and 18.2% in our study).

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C-563 Safety evaluation of gelatin microsphere (GMS) with changeable dissolution time as an embolic agent with regard to our experience of clinical use and the possible use of GMS as a drug delivery system (DDS) N. Nitta1, S. Ohta1, T. Tanaka1, R. Takazakura1, T. Toyama1, S. Kanasaki1, Y. Nagatani1, N. Kono1, A. Furukawa1, M. Takahashi1, K. Murata1, T. Sakamoto1, T. Sakamoto2, Y. Tabata3; 1Otsu/JP, 2Kohka/JP, 3Kyoto/JP (r34nitta@yahoo.co.jp)

Purpose: To perform an initial effectiveness evaluation of GMS impregnated with cisplatin as a sustained-release embolic agent.Methods and Materials: To evaluate antitumor effect, sustained-release cisplatin gelatin microsphere (Cis-GMS) was used in the size of 50-100 um and administrated in doses of 10-4 0 mg (average: 23.2 mg). We used Cis-GMS in which 10 mg of cisplatin was contained in 1 g of GMS. Regarding the method of use of Cis-GMS, we selected the tumor area by a microcatheter and performed embolization by injecting only Cis-GMS after confirming tumor staining by CTA or DSA. Study subjects were 25 patients with primary hepatocellular carcinoma (15 male and 10 female, 47-85 years old; mean 67.4). TAE performed a total of 30 times.Results: All embolization procedures using Cis-GMS were performed successfully, free of serious complications. The local control was good in about 70% judged by CT after one month. Good local control was defined as all the nodules for treatment being unstained or having disappeared completely. In all cases judged as poor local control, the sizes of all nodules were reduced after one month. Regarding renal toxicity, no patient showed renal dysfunction with this impregnation dose.Conclusion: Cis-GMS (50-100 μm) exerts maximum antitumor effect by both embolization and controlled release. In the future, GMS is likely to become clinically available and it will be necessary to evaluate Cis-GMS’s effect by increasing the impregnation dose of cisplatin.

C-564 Clinicopathologic features and results of transarterial chemoembolization for nephroblastoma J. Li, J. Chu; Guang Zhou/CN (truechu@hotmail.com)

Purpose: To describe the clinicopathologic features produced by transarterial chemoembolization in nephroblastoma.Methods and Materials: Preoperative TACE was carried out in 22 patients with nephroblastoma. Post-TACE response, clinicopathologic features include tumor necrosis, interstitial fibrosis, lymphocyte infiltration, median mitotic index and me-dian apoptotic index were recorded. p53, Bcl-2 and Bax protein expression were probed with immunohistochemistry. We also observe the pathological difference of nephroblastoma between those with TACE and without TACE.Results: In TACE and NO-TACE groups, the average area of necrosis in tumor sections was 63.5% and 15%; the percentage of tumor with moderate to severe interstitial fibrosis was 64.8% (14/22) and 18.2% (4/22). The median mitotic index was 1.4 in tissue of the TACE group which was higher than NO-TACE group 0.19 (Uc=55.7, p 0.01). In TACE group, the median apoptotic index of tumor cells was 28.1 per 10 microscopic fields, significantly higher than 12.8 per 10 fields in NO-TACE group (Uc=109.00, p 0.05). Expression of p53 and Bcl-2 protein did not differ between the groups, but Bax protein expression in the TACE group (85%) was significantly higher (p 0.05) than NO-TACE group (40.0%).Conclusion: The preoperative interventional treatment realizes its therapeutic effects mechanism in the following aspects: inducing the tumor cell necrosis and de-generation, boosting interstitial fibrous tissue hyperplasia in tumor and lymphocyte infiltration, inhibiting tumor cell growth, and inducing apoptosis of tumor cells.

C-565 The efficacy and outcome of dialysis line stripping S.S. Iyengar1, A. Abdellaoui1, J. Tee2, J. Stratton2, A. Edwards2; 1Plymouth/UK, 2Truro/UK (srikanthiye@gmail.com)

Purpose: To evaluate the efficacy of salvaging failing haemodialysis catheters by the method of Percutaneous Fibrin Sheath Stripping (PFSS) using urea reduction ratio (URR) and observe the patency of the line following the procedure.Methods and Materials: 45 consecutive patients had 68 PRSS procedures performed at our institution over a period of 33 months. They were referred due to problems with dialysis flow rates and adequacy of dialysis as measured by numer-ous criteria including URR. The initial technical success of PFSS was recorded and additional measures of URR were made pre and post the PFSS procedure. A measure of overall line patency following the procedure was also recorded.Results: Technical success rate was 91.2%. There was a significant improvement in the post-stripping mean URR of 68.3% (SD - 5.0, 95% confidence interval 67.0 to 69.7) compared to a pre-stripping mean URR of 60.9% (8.6, 58.7 to 63.2)

(P 0.0001). The PFSS procedures resulted in a post-stripping URR of 65% or greater in 46 out of 58 cases. The mean catheter patency post-stripping was 112.7 days (range 14-377). No acute complications were recorded. Two cases of line sepsis occurred at 44 days and 105 days, respectively, and were probably not related to PFSS.Conclusion: PFSS prolongs the catheter life comparable to that of a new catheter and increases URR to an adequate level for dialysis.

C-566 The need for level 2 critical care beds in patients undergoing elective endovascular aneurysm repair (EVAR) A. Kheir, G. Danjoux, P. Walker, A. Parry; Middlesbrough/UK (ammar.kheir@doctors.org.uk)

Purpose: The inappropriate use of level 2 critical care beds has led to cancella-tions of procedures due to lack of beds. Do we need level 2 critical care beds for all elective EVAR patients?Methods and Materials: A retrospective study was conducted of all patients un-dergoing elective EVAR between November 2002 and March 2006. Prospectively collected data from Vascular Pre-Assessment Clinic (VPAC), case notes, HDU records and radiology data for procedure length and blood loss were reviewed. Particular attention was paid to the duration of HDU and total in-patient stay and whether any patients received any interventions that could only be given on level 2 or 3 critical care facility.Results: During the study period, 66 patients underwent EVAR outside of any trials. 15:1 male to female ratio and median age was 73 (range 54- 89). Median HDU stay post-EVAR was 23 hours (range 5-244 hours). Median procedure length was 1 hr 55 min (range 1 hr-4 hrs 5 min). Median blood loss was 250 mls (range 25-1300 mls). Thirty day mortality was one patient (1.5%). Post-operative morbidities were four patients (6%). Level 2 critical care intervention was required in six patients (9%). Old age 80 yrs, metabolic equivalent task 4 and prolonged procedure were associated with the use of level 2 intervention but were not strongly predictive.Conclusion: HDU resources are not required for the majority of patients. Younger fit patients with anticipated uncomplicated procedure should be planned to be man-aged on vascular wards. Otherwise, they should be managed in HDU or perhaps treated conservatively.

C-567 Endovascular stent-grafting repair after blunt thoracic aorta injury. Short to long term follow-up: Preliminary results I.S. Kaskarelis, A.A. Parlamenti, K. Kanakakis, V.P. Kostaras, C. Athanasiou, M. Argiriou, I. Kokotsakis; Athens/GR

Purpose: To evaluate the feasibility and safety of endovascular stent-graft (EVS) repair of traumatic thoracic aorta rupture.Methods and Materials: From May 2002 to June 2007, 23 patients underwent EVS repair, for traumatic aortic rupture (isolated 6 cases, or associated with major injuries of other organs). Spiral CT followed by angiography was used for diagno-sis. CT also assessed the efficacy of the procedure at follow-up (2nd day, 3- 6 -12 months after the implantation and yearly thereafter). The endovascular graft was deployed via femoral artery access. The delay between trauma and management was 5.3 hours.Results: Transluminal placement of the endovascular device was technically successful in all patients (technical success 100%). All patients underwent suc-cessful exclusion of their thoracic pseudoaneurysm. One required a second graft deployment. The proximal covered graft portion was placed intentionally across the left subclavian artery in two pts. One patient died on the operative bed (autopsy: portal vein rupture/30-day mortality: 4.35%) and one 40 days after the interventional treatment (due to concomitant injuries/ short term mortality rate: 4.35%). None of the remaining pts developed major procedure related complica-tions after a mean follow-up of 18.45 13 months; while for 12 patients the mean follow-up was 29 14 months (14-62 months) and for 7, the mean follow-up rose up to 38.86 15.84 months.Conclusion: Endovascular stenting can be considered as a safe, fast and less invasive treatment modality for blunt thoracic aortic injury in the therapeutic algorithm of patients especially those with concomitant injuries.

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C-568 Liver radioembolisation with Y90 loaded resin microspheres: Our three year clinical experience A. Alonso, B. Zudaire, A. Viúdez, P. Garrastachu, B. Gil, B. Sangro, J.-I. Bilbao; Pamplona/ES (bzudaire@unav.es)

Purpose: To evaluate the safety and outcome of liver radioembolisation with Y90 loaded resin microspheres. To show the relevance of a multi-disciplinary approach.Methods and Materials: Between 2003 and 2006, 93 patients underwent liver radioembolisation at our institution for the treatment of HCC (40), metastasis from colorectal carcinoma (20), breast (6) and other metastasis (27). Median activity administered was 1.74 Gbq (range: 0.31-3.25). Estimated dose delivered to the tumor and non-tumoral tissue was 132 and 33.9 Gy, respectively. Patient selection and activity calculation was modified during the three year period.Results: Within 18 months following treatment, life-threatening liver toxicity and death were reported in 3 patients. Control rate for HCC was achieved in 98% of patients with 38% rate of progression with new lesions. Median progression-free interval and overall survival for colorectal carcinoma were 9.8 and 15.7, and 13.7 and 21.0 m for breast cancer.Conclusion: Radioembolisation with 90Y-loaded resin microspheres is feasible in most patients with liver tumors but requires a multidisciplinary team. We developed selection criteria and dose calculation algorithms that allow us to consider RE as a safe procedure that achieves a durable local control of disease in most cases.

C-569 Transjugular intrahepatic portosystemic shunt (TIPS) creation after liver transplantation M.A. Cura, F. El Merhi, R. Suri, J. Lopera; San Antonio, TX/US (marcocura@yahoo.com)

Purpose: The purpose of this study is to evaluate the feasibility and outcome of TIPS creation after liver transplantation.Methods and Materials: 6 TIPS were created in 6 adult patients with recurrent cirrhosis due to hepatitis C virus (n=5) and recurrent hemagiomatosis (n=1) after liver transplantation. The mean time from liver transplantation to TIPS was 35.8 months (range 18 to 68 month) for refractory ascites (n= 4), hydrothorax (n=1) and variceal bleeding and ascitis (n=1). All patients were followed to either time of re-transplantation or death.Results: No technical difficulties were encountered in TIPS creation in any of the patients. The mean follow-up after TIPS was 8 months (range 2 to 18 month). 2 patients underwent re-transplantation at 2 and 3 months. 1 patient (pt) demonstrated significant improvement in ascitis and variceal bleeding but he died 11 months after TIPS creation due to sepsis. 1 pt demonstrated complete resolution of ascitis at 13 months follow-up, after TIPS revision of hepatic vein stenosis. 2 pts revealed patent TIPS at 9 and 18 months after TIPS creation with mild improvement in ascitis and hydrothorax respectively.Conclusion: TIPS creation is technically feasible and should be considered a treatment option and a bridge to re-transplantation in cases of allograft cirrhosis and portal hypertension.

C-570 Contrast-enhanced ultrasonography: Utility in the assessment of therapeutic response after uterine fibroid embolization P. Bermudez, J. Falco, J. Perendreu, J. Fortuño, J. Branera, E. Ballesteros; Sabadell, Barcelona/ES (jbranera@mac.com)

Purpose: To compare the diagnostic accuracy of contrast enhanced ultrasonogra-phy (CE-US) to that of contrast enhanced magnetic resonance imaging (CE-MRI) in assessing the therapeutic response after uterine fibroid embolization.Methods and Materials: Thirty patients were evaluated with CE-US and CE-MRI before and after uterine artery embolization. Therapeutic response was defined as the absence of vascular supply and decrease in fibroid/s size. Follow-up was performed during a period of 15 days to three months. The changes in vascular supply and volume were observed in both techniques and compared with previ-ous studies.Results: Therapeutic response was observed in 25 patients with total correla-tion between CE-US and CE-MRI studies. In 5 patients failure in treatment was observed; both CE-US and CE-MRI demonstrated vascular supply to the fibroids as well as no change in volume.Conclusion: CE-US is a useful technique for evaluating the therapeutic response after uterine artery embolization that has a good correlation with CE-MR and therefore could replace it.

C-571 Hepatocellular carcinoma treated with TACE and RFA: Role of perfusion CT in determing therapeutic response D. Ippolito1, F. Invernizzi1, M. Pozzi1, L. Antolini1, S. Sironi1, F. Fazio2; 1Monza/IT, 2Milan/IT (davide.atena@tiscalinet.it)

Purpose: To assess the role of CT-perfusion in detection of blood flow changes related to therapeutic response in HCC treated with trans-arterial chemioemboliza-tion (TACE) or radiofrequency ablation (RFA).Methods and Materials: Twenty-seven patients with confirmed diagnosis of HCC were enrolled in the study: 16 of them were treated with TACE, and nine with RFA. One month after treatment, the patients were examined with CT-perfusion technique (CTp) that consists of the acquisition of 8 dynamic slices/scan per 40 scans after intravenous bolus injection of 50 ml of iodinated contrast at flow rate of 6 ml/sec. Obtained data were analyzed using dedicated perfusion software (CT Perfusion Philips 2.0) to generate a quantitative map of arterial and portal perfusion by means of color scale. The mean values of hepatic perfusion (HP), arterial perfusion (AP), blood volume (BV) and hepatic perfusion index (HPI) were measured at the site of treated lesions and statistically analyzed.Results: Nine out of 25 patients showed residual tumor tissue with the follow-ing perfusion parameters: HP 32.7 15 ml/100 gr/sec; AP 38.4 8.8 ml/min; BV 17.6 9.5 ml/100 mg; HPI 96.2 7.5%. In treated lesions without residual tumor, we obtained the following perfusion parameters: HP: 13.6 5.7 ml/100 gr/sec; AP: 13.1 7 ml/min; BV 6.8 4.8 ml/100 mg; HPI: 13.6 9.2%, respectively. HP, AP, BV and HPI parameters were found to be significantly higher in residual tumor tissue as compared to the lesions without evidence of recurrence (P 0.001). CT-p technique has shown a good relationship between the increase of perfusion parameters and residual viable tumor in treated lesions due to the presence of residual arterial structures.Conclusion: In treated HCC lesions, CT perfusion technique can evaluate blood flow changes, thus allowing assessment of therapeutic response.

C-572 Venous complications after liver transplantation: Endovascular treatment A. Doros, A. Németh, E. Hartmann, Á. Deák, G. Juharosi, Z. Lénárd, I. Fehérvári, Z. Máthé, J. Fazakas, B. Nemes; Budapest/HU (dorattila@yahoo.com)

Purpose: From 1995, more than 300 liver transplantations have been performed in Budapest. The majority of the cases were cadaveric transplantations. Biliary complications occurred in 17%, arterial complications in 4% and venous compli-cations in 0.8%. The therapy was surgical or medical, but interventional radiology played an emerging role.Methods and Materials: 12 patients (5 fem/7 male), mean age 42 years were referred to the interventional radiology unit for therapy. 6 patients had suspicion of VCI stenosis, 3 patients had portal vein stenosis, 2 patients had diminished portal vein flow because of collaterals, and 1 patient had recurrent HCV infection, causing liver fibrosis and portal hypertension. Five caval dilatations and four caval stent implantations have been performed. In cases of portal complications three stents have been implanted, two collateral embolisations were attempted, and one TIPS was created.Results: All the interventions, except the two collateral embolisations, were technically successful. In one VCI stent, in-stent stenosis developed slowly, but it remained clinically silent, and all the remaining stents stayed open, providing good flow. However, four patients died during follow-up due to septic complications not related to the intervention. Two patients with minimal portal flow are well with good liver function.Conclusion: Venous complications are relatively rare after liver transplantation. In cases with vena cava complications surgery is difficult, therefore treatment with minimally invasive methods gained an established role. In our department, after the first successful cases, the first line therapy of complications became interventional radiology in most vascular and non-vascular complications.

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C-573 Interventional radiology management of pediatric patients with biliary complications following liver transplantation R. Miraglia, L. Maruzzelli, S. Caruso, M. Milazzo, G. Marrone, G. Mamone, V. Carollo, A. Luca, B. Gridelli; Palermo/IT (rmiraglia@ismett.edu)

Learning Objectives: To review indications and technical consideration of inter-ventional radiology procedures in patients with biliary complications (BC) after pediatric liver transplantation (PLT).Background: BC following PLT occurs in 20-40% of patients. Most BC develop during the first 3 months after transplantation, although some strictures and stones develop months to years after transplantation. Untreated BC are associated with a high rate of morbidity and mortality.Procedure Details: Indications of interventional radiology procedures in PLT recipi-ents with BC are reviewed. Technical aspects, results and potential complications achievable with interventional radiology procedures (percutaneous trans-hepatic cholangiogram, biliary catheter placement, bilioplasty, recanalization of occluded hepatico-jejunostomy with colapinto needle, atrophy induction of excluded bile ducts with percutaneous alcohol injection, bile leak drainage) are described.Conclusion: Percutaneous management of BC, in pediatric patients, is safe and effective increasing patients and grafts survival and avoiding, in majority of cases, the need for surgical revision or retransplantation.

C-574 The difficult CT guided biopsy C.K.L. Cook1, K. Balasubramaniam2; 1Weston-super-Mare/UK, 2Bristol/UK

Learning Objectives: We describe techniques used to perform difficult computed tomographic (CT) guided biopsies of the abdomen or pelvis.Background: Although the majority of the CT guided biopsies are straightforward, several problems may be encountered. The target may lie deep within the pelvis and direct access is prevented by the iliac wings. Second, the lesion may be surrounded by bowel. Finally, the depth of the lesion may necessitate the use of a long needle for which there is no space between the patient’s skin surface and the CT gantry.Procedure Details: If the lesion lies deep within the pelvis, or behind bowel loops and not in an axial plane, we describe the use of multi-planar reconstructions, sagittal angle measurement and CT gantry angulation to allow accurate needle placement. Using this technique, the needle is both correctly angled with the CT laser markers and also results in subsequent scans being in the plane of the needle track. Furthermore, if the biopsy cannot be performed due to multiple bowel loops, we describe how bowel may be pushed from the biopsy path by needle angulation. We also describe how a double needle puncture (one short and one long) can be used for larger patients when deep biopsies are being performed. These cases necessitate the use of a long biopsy needle for which there would otherwise be no clearance within the CT gantry.Conclusion: These techniques allow the biopsy of lesions deep within the pelvis, surrounded by bowel, and in patients of large habitus.

C-575 Hepatocellular cancer response to radiofrequency tumor ablation: Contrast-enhanced ultrasound T.V. Bartolotta, A. Taibbi, M. Galia, G. Malizia, G. Runza, G. Lo Re, M. Midiri; Palermo/IT (tv_bartolotta@yahoo.com)

Learning Objectives: To illustrate the spectrum of contrast enhanced ultrasound (CEUS) findings in the assessment of radiofrequency ablation (RFA) therapeutic response of hepatocellular carcinoma (HCC).Background: RFA is increasingly being used as percutaneous treatment of choice for patients with early-stage HCC. An accurate assessment RFA therapeutic response is of crucial importance, since a complete tumor ablation significantly increases patient survival, whereas residual unablated tumor calls for additional treatment. Recently, CEUS has become available for RFA assessment. Advan-tages and limitations of CEUS are described on the basis of a series of 337 RFA treated HCC.Imaging Findings: At CEUS, a complete response is considered achieved when there is no enhancing portion within or at the margin of the ablation zone during the hepatic arterial phase (HAP). Residual unablated tumor is defined as a portion of treated HCC showing persistent hypervascularity in the HAP, usually appearing as an irregular peripheral-enhancing focus in the ablation zone, either located within

the edge (ingrowth) or around a treated nodule and in continuity with its border (outgrowth). A uniform and thin peripheral rim of contrast enhancement surround-ing the ablated zone in a rindlike fashion should be regarded as benign reactive hyperaemia, whereas a transient hyperechoic area in the HAP may be related to the presence of arteriovenous shunting.Conclusion: Awareness of CEUS findings make the radiologist to confidently detect residual disease after RFA of HCC, thus allowing retreatment even in the same RFA session and resulting in a better patient management.

C-576 A review of colonic stenting: Achieving a successful outcome F.S. Ahmad, N. Fotiadis, A. Saini, T. Sabharwal, A. Adam; London/UK (farhan@doctors.org.uk)

Learning Objectives: To review the indications for fluoroscopically guided colonic stent deployment in patients presenting with acute colonic obstruction. To illustrate step-by-step procedural details, including alternative techniques, common pitfalls and tips and tricks employed when the procedure is technically challenging. To discuss aftercare and potential complications.Background: Acute left sided colonic obstruction is a common surgical emergency. Surgical treatment of these acutely unwell patients is associated with a high morbid-ity and mortality and often requires a staged procedure. Colonic stenting is now a recognised technique for the decompression of malignant left sided colonic obstruc-tion prior to definitive surgical treatment or as palliation in inoperable cases.Procedure Details: A pictorial review, based on the authors’ extensive experience, is used to describe the pre-procedural assessment, procedural technique and post procedural management of patients undergoing colonic stenting. Emphasis is given to technically demanding cases where we describe procedural tips and tricks to improve the chances of a successful outcome. Potential complications and aftercare are discussed.Conclusion: Fluoroscopically guided stenting is used in acute colonic obstruction to palliate inoperable cases or as a bridging procedure to definitive surgery. Inter-ventional radiologists have a key role in the management of these patients. Success depends on initial patient assessment and preparation, operator technique and attention to aftercare. In our own centre this procedure is an established part of the care pathway in patients presenting with colonic obstruction. This technique should be readily available in hospitals where acute surgical patients are admitted.

C-577 Percutaneous treatment of bone tumors and tumor-like lesions by radiofrequency thermal ablation and/or cementation F. Ruiz Santiago, M. Castellano García, M. Ruiz Garcia, J. Tristán Fernández, J. Martinez Montes, J. Molina Nuevo; Granada/ES (ferusan@telefonica.net)

Learning Objectives: 1. To know the indications of radiofrequency thermal abla-tion and cementation in bone tumors or tumor-like lesions. 2. To describe both techniques, the follow-up of treated cases, results and complications.Background: Image-guided thermal radiofrequency ablation has been used to treat benign bone tumors and tumor-like lesion as a single modality or as an adjunct to surgical therapy. In metastasis, it has proved useful as a palliative medium for relieving disabling pain. Percutaneous delivery of methyl methacrylate has also been used to palliate pain in patients with vertebral and skeletal neoplasm and to prevent pathological fractures. A combination of the two procedures is useful for both purposes: Destruction of tumoral tissue and strengthening of bone architecture.Procedure Details: We present a simplified approach to tumors using a single point of entrance for both, radiofrequency thermal ablation and percutaneous osteoplasty. We show examples of treatment of intra- and extra-articular lesions, including cases of osteoid osteoma, osteoblastoma, chondroblastoma, esosinophilic granuloma, giant cell tumor, and breast and thyroid metastasis. We present a transient pattern of bone marrow edema in healed asymptomatic cases. Examples of complications include a secondary bone necrosis treated by surgery and a case of breaking of the introductory needle.Conclusion: Percutaneous radiofrequency thermal ablation and cementation may be curative in small bone lesions and palliative in greater size or malignant bone lesions. Reviewing indications, technique, follow-up of treated cases and possible complications may be of help to physicians facing this type of pathology.

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C-578 Computed tomography (CT) guided biopsy in small lung nodules (0.5-1.5 cm): Method, results and complications S. Apostolopoulou, P. Filippousis, E. Sotiropoulou, L. Poulou, S. Velitsista, L. Thanos; Athens/GR (sotiriahospitalrad@yahoo.gr)

Learning Objectives: To discuss the indications and contraindications, describe the technique and present complications of percutaneous small lung nodules biopsy.Background: The performance of CT- guided biopsy in case of a small lung nodule might be difficult due to respiratory motion. Thus, it is very common to sample normal lung tissue rather than tissue from the nodule resulting in lower diagnostic accuracy.Procedure Details: 1. Review of indications and contraindications. 2. Diagnostic CT-imaging. 3. Biopsy technique (choice of needle, access route).4. Outcomes (including clinical results, complications and patient management).Conclusion: This exhibit shows that transthoracic CT-guided needle biopsy of small lung nodules is safe and efficient. Lesion size and location of the lesion are factors affecting the outcome of the procedure.

C-579 Let us drain this collection! E. Crespo Vallejo, A. Litcheva Gueorguieva, E. Huelga Zapico, J. Gredilla Molinero, A. Iñiguez Gomez, N. Arevalo Galeano; Madrid/ES (assialag@excite.com)

Learning Objectives: To explain easily the procedure and risks of draining an intraabdominal collection under CT or US guidance.Background: Percutaneous abscess drainage is a very safe procedure, with very few risks for complications. In most of the cases, it is preferred to open surgical abscess drainage. An aggressive practical approach using simple devices and techniques may yield success with few complications.Procedure Details: In this presentation, we describe the current procedure con-cepts based on our 5 years of experience at the emergency radiology department in draining intraabdominal collections. We explain the indications, procedure planning and risk assessment, approach technique, outcome and complications.Conclusion: CT and US are excellent in identifying abscesses and in guiding percutaneous drainage. The radiologist must be trained to perform preprocedure evaluation with the purpose of choosing the appropriate material and technique to carry out the procedure with minimal risk to the patient.

C-580 Potential complications of percutaneous vertebroplasty: How to prevent and manage them T. Moser, X. Buy, J.-L. Dietemann, A. Gangi; Strasbourg/FR (afshin.gangi@chru-strasbourg.fr)

Learning Objectives: To illustrate the potential complications of percutaneous vertebroplasty while discussing situations at risk and methods to prevent them in light of our 15 years experience with the technique.Background: Percutaneous vertebroplasty is a safe technique with proven efficacy for management of osteoporotic and pathologic fractures, as well as hemangiomas. Its complications are infrequent when adequate technique and materials are used.Procedure Details: Some situations with increased risk of complications can be identified and classified according to the stage of the procedure involved: patient selection (patients at risk, vertebrae at risk, vertebral puncture (needle wounds), ce-ment injection (systemic toxicity, vascular and non-vascular leakage) and follow-up (instability, infection, secondary fracture). Special attention and adequate technique are mandatory to obviate potential complications. When complications nevertheless occur, some salvation techniques aim at reducing their medical consequences.Conclusion: Percutaneous vertebroplasty is an efficient procedure whose poten-tial complications should be well known and prevented by a rigorous technique. Knowledge of the management of complications is also crucial.

C-581 Optimized CT-guided coaxial core biopsy of retroperitoneal masses J. Stattaus, H. Kuehl, J. Kalkmann, M.R. Nowrousian, K.A. Metz, M. Forsting, S.C. Ladd; Essen/DE (joerg.stattaus@uni-due.de)

Learning Objectives: To illustrate the technique of CT-guided coaxial core biopsy in non-organ-bound retroperitoneum. To describe suitable indications, access routes, and procedure details. To show the results based on a series of 49 patients.Background: Different percutaneous biopsy techniques including fine-needle

aspiration and core biopsy have been used for diagnosis of retroperitoneal masses. A relevant precondition for successful tumor typing and subtyping in lymphoma and sarcoma is an optimized tissue sampling technique, with amount and quality of material being the main issues. We will describe technical challenges of CT-guided coaxial core biopsy in 49 patients with undetermined masses in the free retroperitoneal space.Procedure Details: Predominantly, a 15G guidance needle with a 16G semi-automated core biopsy system was used. The guidance needle was advanced on different access routes under intermittent CT control, preserving critical anatomical structures. All biopsies were technically successful, and no relevant complication occurred. Using the coaxial technique, up to 4 specimens could be obtained. Combined with the large-diameter biopsy needle, this offers adequate material for detailed histopathological and immunohistochemical analyses. Therefore, diagnostic accuracy in differentiation between malignant and benign diseases was 95%. A specific histological diagnosis could be established in 90% of malignant lesions.Conclusion: CT-guided coaxial core biopsy using 16G biopsy needles provides a safe and accurate diagnosis of retroperitoneal masses. This may obviate the need for more invasive and expensive procedures like surgical biopsy. To practice this technique effectively, a precise knowledge of topographic anatomy, safe access routes, and advised needle handling is crucial.

C-582 Artificial pneumothorax with position adjustment for computed tomography-guided percutaneous core biopsy of mediastinum lesions Z. Lin, Y. Li; Fuzhou/CN (linsinlan@yahoo.com.cn)

Purpose: To assess the utility of artificial pneumothorax with position adjustment to gain a pleural space approach in CT-guided core biopsy of mediastinal masses.Methods and Materials: 11 patients (7 men, 4 women; mean age, 45.5 years) with mediastinal lesions were performed percutaneous core biopsies. Under the guid-ance of CT, a 22G lumbar puncture needle advanced into the pleural space. Once the intrapleural position of the needle was confirmed, 200 ml air was administered, resulting in an artificial pneumothorax. The patient’s position was adjusted for mak-ing the lesion as high as possible in the thoracic cavity so that the target could be reached through the air-containing pleural space with less air injection. Adequate air was injected until the lung was displaced from the path of the biopsy needle. Repeat CT imaging was used to guide an 18G core biopsy needle inserted into the lesion, and all patients had at least 1 (range 1-4, mean 1.8) core tissue biopsy. After biopsy was completed, similar amount air was aspirated.Results: In all patients, artificial pneumothorax was initiated, and satisfactory displacement of lung from the biopsy site was achieved. The mean air volume was 680 ml (range 400-1400 ml). The sampling of the target lesion was successful in all patients. A definitive diagnosis was obtained in 10 of 11 biopsies. No post-procedure air leak requiring tube drainage was encountered.Conclusion: Artificial pneumothorax with position adjustment is a safe method that provides access for CT-guided biopsy of mediastinum lesions without traversing aerated lung and decreases the volume of injected air.

C-583 Femoroplasty, ilioplasty and sacroplasty under CT fluoroscopic guidance in the treatment of bone lytic metastases and multiple myeloma C. Pusceddu1, N. Ballicu1, G. Podda1, C. Urigo2, S. Profili2, F. Meloni2, G. Meloni2; 1Cagliari/IT, 2Sassari/IT (claudio.pusceddu@alice.it)

Purpose: To evaluate the feasibility and safety of femoroplasty, ilioplasty and per-cutaneous sacroplasty in the treatment of painful metastases and multiple myeloma osteolytic lesions located in critical areas at high risk of pathological fracture.Methods and Materials: Ten patients (2 men and 8 women, mean age 63 years), affected by metastatic carcinoma and multiple myeloma bone localizations, were treated by percutaneous injection of a polymethylmethacrylate (PMMA) solution into the supracetabular (4 cases), femoral (4 cases)and sacral bone cavity (2 cases). Lesion approach was performed using a 10-gauge bone biopsy needle under CT and fluoroscopic guidance. Subsequently, 8-22 mL PMMA was injected under fluoroscopic guidance. The procedures were performed using local anaesthesia and conscious sedation in all patients. Pain was measured with Huskisson visual analogue scale - VAS - (range 0 no pain, 10 maximum possible pain) before, 24 hours, 1, 3, 6 and 12 months after procedure.Results: Good technical success was achieved in all patients. No major complica-tions were reported. VAS score decreased to a median value of 0 (range 0-1.5). In a median follow-up of 11 months (range 2-27 months), none of the patients developed pathological fracture in the intervention site.Conclusion: Percutaneous osteoplasty of the pelvis and femora is feasible and safe in patients affected by osteolytic metastases and multiple myeloma bone le-

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sions. The acrylic cement injection is a minimally invasive procedure that provides immediate pain relief and contributes to reinforce of bony structure with prevention of pathological fractures and improvement of walking.

C-584 Percutaneous liver biopsy: Analysis of major complications R.G. Lambertini, P.E. Farías, G. Ducrey, A. Gadano, J.C. Bandi, R. García Mónaco; Buenos Aires/AR (roberto.lambertini@hospitalitaliano.org.ar)

Purpose: To analyze percutaneous hepatic biopsies (PHB) to identify the risk fac-tors associated with major complications (MC) and describe the therapeutic and diagnostic algorithm in cases of MC.Methods and Materials: Between 04/2002 and 04/2007, 2193 patients were re-ferred for PHB. Biopsies were performed either by continuous ultrasound guidance (UG) or by ultrasound-marking (UM) of the puncture area. Exclusion criteria (EC) were coagulopathy, chronic aspirin intake and marked ascites. Minor complica-tions were treated symptomatically (data not shown). Active bleeding requiring endovascular or surgical intervention was considered MC.Results: 893/2193 patients had EC and were referred for transjugular approach. Of the remaining 1300, 280 presented focal lesions and 1020 diffuse disease. Nodular biopsies (NB) were performed under UG with 18/20G needles. No major complications were observed in NB. Diffuse biopsies (DB) were obtained with 16G needle: 921/1020 under UG and 99/1020 under UM. 6/1020 DB presented abdominal bleeding, 3/6 occurred in biopsies under UM and 3/6 in biopsies under UG. 2/6 presented acute bleeding in hospital within 2 hs after biopsy and 4/6 were re-admitted by the emergency department 6-8 hs after initial discharge. 2/6 patients with MC showed blood dyscrasias not detected previously. An angiogram was done in all cases with MC, 2/6 stabilized spontaneously, 1/6 was embolized and 3/6 received surgery. No fatal complications occurred.Conclusion: A deficient hemostasis, the use of gross needles and ultrasound mark-ing were the main factors associated with major complications. Fatal complications were avoided by immediate treatment by angiography or surgery when needed.

C-585 Percutaneous radiofrequency heat ablation of malignant extra-hepatic neoplasm C. Pusceddu1, N. Ballicu1, F. Meloni2, G. Podda1, C. Urigo2, S. Profili2, G. Meloni2; 1Cagliari/IT, 2Sassari/IT (claudio.pusceddu@alice.it)

Purpose: To evaluate the feasibility and effectiveness of radiofrequency ablaton (RFA) in the treatment of unresectable extra-hepatic tumors.Methods and Materials: From March 2005 to May 2007, we treated 94 tumors in 64 consecutive patients. Median age was 63 (range 43-82) years. Patients were considered ineligible for surgery for medical comorbidities or refusal of surgery. Localizations of the tumors were head and neck, mediastinum, chest and lung, kidney and adrenal gland, pelvis and bone. The mean size of the lesions was 3.9 cm (range of 07-10). RFA was performed with computer tomography-guided percutane-ous approach using local anaesthesia and conscious sedation in all patients. The therapeutic outcomes were evaluated by contrast enhanced TC after 1, 3, 6 and 12 months. The absence of tumor enhancement TC image was considered to indicate complete tumor necrosis. During the mean follow-up, which was 13 months (2-27 months) in all patients, we evaluated the outcomes of the 94 nodules treated.Results: The procedure was technically successful in all lesions. Complete tumor necrosis was achieved in 58/94 tumors (62%). In two patients with a pelvic recur-rent rectal cancer, an abscess in presacral space and a bladder-rectal fistula after RF treatment was observed. Relapse occurred in 6/94 treated tumors, whereas in other 10 patients, relapse occurred in other sites. 50 patients are still alive and 15 disease free.Conclusion: RFA of unresectable extra-hepatic neoplasms is feasibility and ef-fective method. However it is necessary longer-term studies define the exact role of extra-hepatic RF in the treatment of cancer.

C-586 Pleural complication associated with radiofrequency ablation: Histopathologic findings in rabbit lung models during follow-up period H. Nakada; Miyazaki/JP

Purpose: The purpose of the present study was to describe the time-related his-topathologic findings of the pleura after radiofrequency ablation in peripheral lung region has a high risk of intractable pneumothorax.Methods and Materials: Radiofrequency ablation was carried out on fourteen rabbits’ lungs. Ablated regions were imaged and sacrificed at 1 day, 2 days, 3 days, 4 days, 1 week, 2 weeks, and 3 weeks. We used 17-gauge needles that have eight

retractable hooks with a maximum diameter of 2.0 cm (LeVeen Needle, Boston Scientific). Percutaneous radiofrequency ablation was performed under CT guid-ance at peripheral lung regions including adjacent pleura in ablated area. Isolated lung preparation was evaluated histologically.Results: CT images showed ground glass shadow immediately after radiofrequency ablation. This was complicated with pneumothorax in all rabbits. At the follow-up study, pneumothorax resolved in four rabbits was chased progress until 2-3 weeks. Histologically, there was coagulation necrosis in ablated pleura along with adjacent lung, and breakthrough bleeding was observed at the site of electrode placement from 1 day to 1 week. From 1 week after radiofrequency ablation, partially thickened pleura by granulation tissue were observed. Eventually, the altated area was covered by fibrous capsule of the thickened pleura on 2-3 weeks.Conclusion: These results suggest that the pleural injury associated with radiofre-quency ablation in the normal lung is restored in approximately two weeks.

C-587 Klebsiella pneumoniae liver abscess versus non-Klebsiella peumoniae liver abscess: Comparison of clinical features and outcome of percutaneous drainage H.-P. Hong, P. Kang, S. Kim, H. Park; Seoul/KR (pyeongguk.kang@samsung.com)

Purpose: To compare clinical features, and outcome of percutaneous drainage (PCD) of liver abscesses caused by Klebsiella pneumoniae with those caused by non-Klebsiella pneumoniae.Methods and Materials: 51 patients with pyogenic liver abscess were divided into following two groups according to the results of blood or pus cultures: Klebsiella pneumoniae group (n=30) and non-Klebsiella pneumoniae group (n=21). Clinical features included the underlying disease. Outcome of PCD included the frequency of tube change and duration of PCD tube. Clinical features and outcome of PCD were analyzed and compared between groups.Results: Non-Klebsiella pneumoniae liver abscesses were significantly associated with underlying hepatobiliary diseases, choledochoenterostomy or biliary stent insertion state (p 0.001). Underlying diabetes showed no significant difference between two groups (p 0.05). PCD tube change was required more frequently in Klebsiella pneumoninae group and longer duration of PCD tube (p 0.05).Conclusion: Compared with non-Klebsiella pneumonia liver abscess, Klebsiella pneumoniae liver abscess needs more frequent change and longer duration of PCD tube. Non-Klebsiella pneumoniae liver abscess is more frequently associated with hepatobiliary disease, surgery, or intervention.

C-588 Evaluation of pretreatment apparent diffusion coefficients’ value of hepatocellular carcinoma treated with percutaneous radiofrequency ablation E. Szurowska, J.M. Pienkowska, D. Zadrozny, E. Izycka-Swieszewska, W. Adamonis, M. Dubaniewicz-Wybieralska, M. Studniarek; Gdansk/PL (eszurowska@amg.gda.pl)

Purpose: The purpose of this study was the evaluation of the pretreatment ap-parent diffusion coefficients’ value (ADCs) of hepatocellular carcinomas (HCCs) as a predictive factor of response to radiofrequency ablation therapy (RFA) and investigation of the changes of tumor’s ADCs before and after treatment.Methods and Materials: 47 HCCs foci in 31 patients were prospectively evaluated with diffusion-weighted MR imaging one day before and 6 weeks after RFA using 1.5 T system. ADCs were calculated for each tumors before and after treatment with different b values (b= 0-15; 0-30; 0-300; 0-500; 0-2000 s/mm2). The mean pretreatment and post-treatment ADCs of lesions were correlated to standard measures of therapeutic response (complete or non-complete). Complete response was defined as avascular liver lesion by multislices CT scans performed 6- and 24-weeks after RFA.Results: The complete response of tumors treatment were observed in 35HCCs foci and residual tumors were detected in 12 cases. The mean pretreatment ADCs for low b values (b= 0-15; 0-30 s/mm2) was significantly higher in non-responding lesions than in the completely ablated neoplasm (U-Mann-Whitney-test, p 0.001). The mean post-treatment ADCs of completely responding HCCs increased signifi-cantly 6 weeks after RFA comparing to mean pretreatment ADCs (Wilcoxon-test, p=0.02). No significant change of mean ADCs before and after therapy was noted in residual tumors.Conclusion: High pretreatment ADC for low b values of HCC is predictive fac-tor of poor response to RFA. An increase of post-treatment ADC is observed in completely ablated tumors. These findings can be useful in patients’ qualification and monitoring of RFA therapy.

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C-589 The safety and efficacy of MR-guided focused ultrasound surgery in pedunculated subserosal fibroid of the uterus: Initial experience S.-W. Yoon; Gyunggi-do/KR (jansonsrad@gmail.com)

Purpose: To evaluate the safety and efficacy of MR-guided focused ultrasound surgery (MRgFUS) in pedunculated subserosal fibroid of the uterus.Methods and Materials: During one year, 113 women were treated with MRgFUS for symptomatic uterine fibroid. Uterine fibroid was confirmed by MR image. Among 113 women, 5 women (age range, 33-47, mean age, 42 years) had pedunculated subserosal fibroid of the uterus. Non-perfused volume (NPV) within fibroid on treatment day and the volume change and connection of fibroid to uterus were evaluated on three-month follow-up MRI.Results: The size of fibroid was ranged from 6 cm to 10 cm (mean size, 8 cm). NPV was ranged from 50% to 80% (mean NPV, 63%). On follow-up MRI after 3 months, there was volume reduction in treated fibroid of the uterus (15%~25%, mean 21%). In all cases, there was not a case of disconnection of fibroid from uterus. Patients experienced improvement of bulk-related symptom after treatment (80%).Conclusion: Pedunculated subserosal fibroid of the uterus can be treated safely and effectively by MRgFUS.

C-590 Percutaneous femoroplasty in the cancer patient: A new therapeutic option? C. Pusceddu1, N. Ballicu1, G. Podda1, F. Meloni2, S. Profili2, G. Meloni2; 1Cagliari/IT, 2Sassari/IT (claudio.pusceddu@alice.it)

Purpose: To evaluate feasibility, safety and efficacy of percutaneous femoropasty under CT- fluoroscopic guidance in the treatment of painful osteolytic metastases and multiple myeloma located in the proximal femur with prophylactic bone cement injection in patients with refractory pain and high risk of fracture.Methods and Materials: From November 2006 to August 2007, seven consecutive women (mean age 60 years) affected by metastatic breast carcinoma (six cases), and bone multiple myeloma (one case) with large osteolytic areas of head and neck femur at high risk of fracture were treated with bone-cement injection. All patients were unsuitable candidates for surgery according to multidisciplinary consensus. The lesions were accessed using the 10-gauge bone biopsy needle under CT fluoroscopic guidance with local anesthesia and conscious sedation. Subsequently, under fluoroscopic guidance, 8 mL (5-15 mL) of polymethylmetacrylate (PMMA) were injected into the lesions. In a patient with cortical interruption, asymptomatic small extravasation of PMMA occurred.Results: Good technical success was achieved in all patients. Pain relief was complete within 1 week in all cases. No new femur’s fracture complication occurred after ten months follow-up.Conclusion: Percutaneous femoroplasty of the proximal femur is feasible and safe, and it obtains pain relief and prevents pathological fractures with improvement of walking ability. This procedure can be considered a new therapeutic option for patients with refractory pain and high risk of fracture.

C-591 XperGuide: C-arm needle guidance D. Ruijters1, L. Spelle2, J. Moret2, D. Babic1, R. Homan1, P. Mielekamp1, B.M. ter Haar Romeny3, P. Suetens4; 1Best/NL, 2Paris/FR, 3Eindhoven/NL, 4Leuven/BE (danny.ruijters@philips.com)

Purpose: Pre-operative planning of a path in a CTA dataset and guiding cranial needle insertion under X-ray fluoroscopy.Methods and Materials: A target coordinate in the anatomy of interest within the pre-operative CTA dataset is selected, and a straight path to the target is planned, avoiding the impenetrable bones and major vessels. Multiple paths can be stored. During the intervention, the pre-operative dataset is registered to a peri-operative XperCT dataset, which also registers the CT and C-arm coordinate systems. The C-arm viewing incidence is steered to be tangent to the planned path: the entry view. When the needle is positioned at the entry position and its orientation is tangent to the fluoroscopy image, it can be inserted. The C-arm viewing incidence is then steered to be perpendicular to the planned path: the progression view. In this orientation, the needle can be navigated along the planned path.Results: The proposed method has been applied to navigate along 8 planned paths the embolization of a glomic tumor for two patients. The peri-operative registration takes less than 8 sec. Using this method, it is possible to guide the needle within 5 mm of the planned path.Conclusion: The fluoroscopy navigation, overlaid with the planned path, has been shown to be an accurate tool for needle guidance. The patient orientation differed

between the pre-operative CT and the fluoroscopy guided intervention, but this did not form a complicating factor. The needle accessibility of an intracranial location, however, can be limited per sé by topology of the skull.

C-592 Utility of 3D ultrasound in percutaneous nephrostomy (PCN) insertion L.A. Ratnam, M. Walkden, G. Munneke, S. Nayak, D. Rowlands, D. Nassiri, K. Anson, U. Patel; London/UK

Purpose: To evaluate the accuracy of calyceal puncture using 3D ultrasound compared to 2D ultrasound.Methods and Materials: A series of experiments were conducted with two opera-tors using a renal model. Punctures were performed using the 2D ultrasound probe, followed by wire manipulation into the collecting system. The process was then repeated using the 3D ultrasound probe. Time for puncture and wire manipulation, quality of puncture and global assessment were recorded for each puncture.Results: 3 D punctures take longer (2D: 2 and 1.7 minutes (mins), 3D: 1.9 and 2.1 mins). 2D wire manipulation takes longer (2D: 0.34 and 0.32 mins, 3D: 0.2 and 0.3 mins). The quality of puncture was better with 3D (2D: 1.7 and 2, 3D: 1.8 and 2.2; 1=Poor and 3=Good). Wire manipulation produced a mixed response (2D: 2.2 and 2 mins, 3D: 2.5 and 1.7 mins). Global assessment shows the procedure is easier with 2D (2D: 3.7 and 3, 3D: 5.5 and 4; 1=easy and 10=difficult).Conclusion: The 3D probe was harder to use and takes longer to puncture, but results in better punctures and speeds up wire manipulation. A lighter, more user friendly 3D probe design is required. This should allow for a complete 3D ultrasound, single handed PCN.

C-593 Relationship between efficacy of magnetic resonance imaging-guided focused ultrasound (MRI-FUS) treatment of uterine fibroids and MR-characteristics of the tumors V.Y. Lazutkina, A.V. Stepanov, Y.B. Kurashvili, K.V. Lyadov; Moscow/RU (wisekaa@nm.ru)

Purpose: To study the relationship between MRI-FUS and uterine fibroids MR-types efficacy.Methods and Materials: 400 MRI-FUS procedures were performed in 350 women with uterine fibroids. A combination of FUS remote tumor ablation system (ExAb-late2000, InSightecLtd). under MR control (Signa EchoSpeed 1.5 T) was used. According to comparative MR signal intensity of myometrium and fibroids on T2-weghted images, 3 myoma types were defined: 1.”dark” (hypointensive) - 65.5% (320 pts), 2.”grey” (isointensive) - 18.8% (66 pts), 3.”white” (hyperintensive) - 15.7% (54 pts). MRI-FUS results were evaluated immediately after the procedure using contrast-enhanced MRI. Images analysis was based on fibroid’s non-perfused volume (NPV) and NPV/fibroid volume ratio measurements.Results: Standard FUS-MRI protocol was most successful for “dark” medium-sized myomas treatment (59.7%, 191 pts). For large “dark” myomas (39 pts), adequate result was obtained with prolonged protocol. Standard protocol was ineffective in “white” myomas. In 48 procedures, protocol settings were changed in order to achieve further increase of energy concentration to the myoma and decrease emis-sion to the adjacent structures. In these patients, treatment success was achieved in 77% cases. In 6 cases of large “white” myomas, FUS was performed in 2 phases in 1-30 days interval, with good results in 4 cases. For “grey” myomas treatment FUS-MRI protocol parameters were changed, depending on fibroid’s ability to absorb US energy. In this subgroup, the procedure was successful in 53% of cases.Conclusion: Success of FUS-MRI uterine fibroids treatment is dependent on the tumor’s MR-characteristics. Further studies are needed to provide more detailed evidence on the criteria for patient selection and treatment efficacy indicators.

C-594 Postsurgery complications: Minimally invasive treatment under CT-guidance S. Mylona, M. Gravanis, E. Syristatidou, D. Kyriakoulis, A. Anagnostara, N. Batakis; Athens/GR (sofimylona@yahoo.com)

Purpose: To present the effectiveness of percutaneous treatment under CT- guid-ance of postsurgery complications as the result from 6 years of experience.Methods and Materials: From March 2000 to August 2007, we performed 242 percutaneous CT-guided drainages in 205 patients (119 males/ 86 females) who suffered from complications after an operation in abdomen. The patients under-went surgery as follows: 88 cholocystectomies (with laparoscopy or laparotomy), 25 gastrectomies, 27 enterectomies, 22 hepatectomies, 19 splenectomies, 13 pancreatectomies, and 11 nephrectomies. All patients presented with fever and/or

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pain in the immediate or in the late postoperative period and the diagnostic CT revealed fluid collection at the surgery area. A percutaneous pigtail catheter 8-14 F was placed under CT guidance. The catheter was removed after a mean time of 8 days when it ceased draining and patients symptoms lapsed. No complications were observed.Results: Drainage showed purulent content in 155 patients, in 18 bilious content, urine in 10 and hemoragic content in 22 patients. Two hundred thirty-one/242 col-lections (95.5%) were totally drained. Two patients after echinococcectomy repeated the operation and in 7 cases, loculations were observed and an additional catheter placed between the 3rd and 10th day. After collection’s cultivation, an additional treatment was administrated.Conclusion: CT-guided percutaneous drainage of post-surgery complications is a fast, convenient and effective method of treatment, with the advantage of being minimally invasive.

C-595 Results of oxygen-ozone chemodiscolysis in different types of disc disease N. Limbucci, V. Zecca, L. Sacchetti, F. Fasano, L. Zugaro, M. Gallucci; L’Aquila/IT (niclimb@libero.it)

Purpose: The indications of oxygen-ozone chemodiscolysis are not well established. Our purpose is to review the last 100 CT-guided chemodiscolysis performed in our institution and evaluate patients’ outcome on the basis of the type of disc disease.Methods and Materials: We reviewed MRI images and clinical data of 120 consecu-tive patients who underwent chemodiscolysis and intraforaminal oxygen-ozone and steroid injections. Patients were classified on the basis of the type of disc disease (bulging, protrusion, extrusion, free fragment); patients with severe degenerative bony changes were classified into a different category independently on the grade of disc disease. All patients had previously been contacted (6 months after inter-vention); modified McNab method data were available. Treatment was successful if McNab method showed excellent or good outcome. We evaluated success rate for each patient group. Chi-squared test was performed.Results: Among 120 patients, we treated 43 extrusions (4 with free fragments), 35 protrusions, 7 bulging discs, and 23 degenerative bony abnormalities. Treatment was successful in 29 extrusions (67.4%), 28 protrusions (80%), 3 bulging discs (42.8%), 12 patients with degenerative bony abnormalities (52.2%). The outcome difference between herniations (protrusion, extrusion) and degenerative bony abnormalities was statistically significant (P 0.05).Conclusion: A statistical trend reveals better results in protrusions than extrusions, although that is not statistically significant. Results are significantly better in hernia-tions than in degenerative bony abnormalities. However, in selected cases also those patients can be treated successfully. More data are needed about bulging discs.

C-596 Post-radiofrequency ablation syndrome after percutaneous radiofrequency of abdominal tumours A. Ianniello, G. Carrafiello, D. Laganà, F. Fontana, P. Nicotera, C. Fugazzola; Varese/IT (ianand@libero.it)

Purpose: To study and to evaluate prospectively post-radiofrequency ablation syndrome and to determine its impact on the quality of life in the 15 days after percutaneous radiofrequency ablation (RFA) treatment.Methods and Materials: We performed an internal review board-approved prospective study of the delayed symptoms that occurred after 71 consecutive RFA sessions in 53 patients (12 women, 41 men; age range, 45-83 years; mean age, 71.6 years) with 45 primary liver tumours, 34 liver metastases, 3 renal cell carcinoma [RCC], 2 residual lesions from RCC after nefrectomy and 1 pancreatic metastases from RCC.Results: Postablation symptoms occurred in 17/53 (32%) patients. Six out of 17 patients developed low-grade fever (from 37.5 °C to 38.5 °C). Other symptoms included delayed pain (9/17), nausea (7/17), vomiting (3/17) malaise (3/17) and myalgia (1).Conclusion: Postablation syndrome is a common phenomenon after RFA of solid abdominal tumours. In our study, but also in the previous ones, the occurrence is observed in approximately one thirds of patients. Patients should be informed that these symptoms are self limiting after RFA and most patients should be able to resume near complete preprocedural levels of activity within 10 days after the procedure.

C-597 Safety, efficiency and cost-effectiveness in CT-guided biopsies performed on an out-patient basis P. Filippousis, E. Sotiropoulou, S. Apostolopoulou, A. Bouga, L. Poulou, L. Thanos; Athens/GR (sotiriahospitalrad@yahoo.gr)

Purpose: To determine the safety, efficiency and cost-effectiveness of CT-guided biopsies performed on an outpatient basis.Methods and Materials: During the last 14 months, we performed 1250 biopsies under CT guidance, of which 850 were biopsies on an outpatient basis (age range 28-75 years) involving liver, lung, kidney, adrenal, bone and lymph node lesions. All procedures were performed under local anesthesia (lydocaine 2%), using either an 18 gauge automatic cutting needle or a fine needle aspiration. Inclusion criteria were: platelet count 50000, prothrombin time less than 15 seconds and international normalized ratio 1.5.Results: Biopsies were diagnostic in 88% of cases and non diagnostic in 12% of cases. In these cases, a second procedure was performed. Blood pressure, pulse rate and body temperature were taken at 15 minute intervals for one hour and at 30 minute intervals for an additional three hours (for a total of 4 hours). Complica-tions: Pneumothorax occurred in 20 patients but only in eight cases a chest tube had to be inserted in the CT scan room. In all other cases, the air was manually aspirated and no further treatment was necessary. In these cases, all patients required an inpatient hospital stay. No other major complications occurred. Before outpatients were discharged, the skin entry was inspected for evidence of bleeding or hematoma. The cost of outpatient biopsies was substantially lower than that of inpatient procedures.Conclusion: CT-guided biopsies performed on an outpatient basis are a safe, efficient and cost-effective diagnostic method.

C-598 Post-ablation syndrome in 70 patients treated with radiofrequency ablation P. Filippousis, E. Sotiropoulou, S. Apostolopoulou, S. Velitsista, A. Bouga, L. Thanos; Athens/GR (sotiriahospitalrad@yahoo.gr)

Purpose: To evaluate the incidence of post-ablation syndrome and determine its impact on the quality of life in the first 8 days after therapy.Methods and Materials: In the past 12 months, we performed in our institution radiofrequency ablation (RFA) sessions in 70 patients under CT guidance. 62 patients underwent RFA for liver tumors, 6 for renal tumors and 2 for adrenal tu-mors. Time of ablation was 12-25 minutes. We used 2 types of needle electrodes and electrosurgical generators: spiral (Miras) and hooked (7 and 9 array, Rita). Liver tumors measured from 2 to 7 cm, kidney tumors from 2 to 5 cm and adrenal tumors 2 and 4 cm.Results: 46 (74.19%) patients who underwent liver RFA presented with low-grade fever and 52 (83.87%) had flu-like symptoms (fever, malaise, chills, delayed pain, nausea). 2 (33.3%) patients who underwent renal RFA presented with low-grade fever and 3 (50%) with flu-like symptoms. 1 (50%) patient with adrenal tumor pre-sented with low-grade fever. 4 patients presented with no symptoms at all. These symptoms described above peaked 1 to 3 days after therapy and resolved within 8 days. A complete post-ablation syndrome occurred in those patients who had lesions greater than 4 cm and in those in which treatment lasted more than 15 minutes.Conclusion: Complete post-ablation syndrome occurs in the majority of patients, resolves within 8 days approximately after each RFA session and is correlated to lesion size and treatment duration.

C-599 CT-guided tumor implantation: Animal model S.C.A. Herber, K. Trappe, C. Winkel, M.B. Pitton, C. Düber; Mainz/DE (herber@radiologie.klinik.uni-mainz.de)

Purpose: Determination of safety and efficacy of CT-guided implantation of a VX-2 tumor in the rabbit kidney.Methods and Materials: VX-2 tumor model for renal cell carcinoma was established to prove the impact of local tumor therapy. For tumor generation tumor bearing tis-sue cubes were implanted via 16-Gauge trokar needle in 61 kidneys in 40 rabbits. Tumor was taken from a single donator. Image guidance was performed with CT-flouroscopy (thickness 1 mm; 20 mAs, 80 KV). Controls comprised Multisclice-CT after 7, 14, and 21 days.Results: 21/40 animals were implanted bilaterally. Implantation was carried out as follows: cranial kidney 19/61; middle 6/61; caudal kidney 36/61. Tumor growth could be achieved in 57.4%. Procedure time for tumor implantation was 8.2 4.1 minutes. Tumor growth at the implantation side was found in 91.4% (32/35 tumors) whereas in 3/35 cases tumor growth occurred in distance to the implantation point. Mean

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time for tumor growth was 16.2 7.4 days (8.0-41.0 days). Mean tumor size was 16 8 mm. Tumor growth was intraparenchymal, expophytic and mixed in 22/35, 5/35, and 8/35 cases, respectively. Extrarenal tumor implantation occurred in 11/61 kidneys (18.0%) at the path of the needle insertion. Major complications were found in 10/61 animals (16.4%) comprising 1 renal bleeding, 1 urinoma and 3 deaths (3/3 associated to respiratory depression).Conclusion: Implantation of VX-2 tumor in the rabbit kidney guided by CT-fluo-roscopy proved to be accurate and effective. The complication rate was moderate but the method was burdened by implantation metastases in the perirenal space that prohibited further procedures.

C-600 MR imaging for the assessment of treatment response after radiofrequency ablation of hepatocellular carcinoma: An explant correlation S. Rha1, H. Hussain2, B. McKenna2, W. Weadock2, H. Nghiem2; 1Seoul/KR, 2Ann Arbor, MI/US (serha@catholic.ac.kr)

Purpose: To evaluate MRI for the assessment of treatment success of radiofre-quency (RF) ablation of hepatocellular carcinoma (HCC) with explant correlation in patients with cirrhosis.Methods and Materials: Thirteen patients with 17 HCC nodules had RF ablation and post-ablation MRI within 90 days prior to liver transplantation. The pre-and post-ablation MRI were reviewed by two radiologists who were blinded to the pathology results of the explanted liver to determine the success of treatment. The readers determined, by consensus opinion, the percentage of necrosis and residual tumor using T1W gradient echo (GRE), T2W fast spin-echo, and dynamic gadolinium-enhanced 3D spoiled GRE images. One experienced pathologist re-viewed the slides of explanted liver and determined the percentage of coagulative necrosis within the ablation cavity. MRI findings were compared with histologic data of the explanted liver.Results: MRI enabled correct diagnosis of all 6 completely ablated tumors and one 75% necrotic HCC. MRI overestimated the area of necrosis in seven tumors by 5-45%, and underestimated the area of necrosis in three tumors by 25-40%. MRI did not depict residual tumor in five partially necrotic tumors. While specificity and positive predictive values for the depiction of residual tumor were 100%, both sensitivity and negative predictive value were 55%.Conclusion: Although the specificity of MRI for the depiction of residual tumor following RF ablation is high, it is limited in its ability to depict small foci of residual tumor in RF ablation cavities.

C-601 Self-expanding metallic ureteral stents to treat ureteral stenosis after kidney transplantation F. Diaz Romero, L. Delgado Plasencia, E. López-Tomassetti Fernández, E. Torres Monzón, I. González García, H. Vallés González, T. Pérez Albelo, P. Gutiérrez Hernández; Santa Cruz de Tenerife/ES (luciano_delgado1@yahoo.es)

Purpose: The incidence of ureteral stenosis after renal transplantation ranges from 2-12%. The aim of the present study is to evaluate the efficacy of self-expanding ureteral metallic stents to treat this common complication. Its present role has been scarcely reported.Methods and Materials: Among 629 transplantations performed between Octo-ber 2000 and May 2006, twenty two patients with ureteral stenosis were treated using implantation of a self-expanding metallic ureteral stents by anterograde percutaneous access.Results: The average age of the patients was 47 years (range 23-68 years). Four woman and 18 men were treated. The strictures were located as follows: 16 in the distal ureter, 4 in pyeloureteral junction and 2 in ureterovesical junction. The interval between transplantation and stenosis ranged from 1 month to 10 years. All patients were followed-up after stent placement during 12 months. The patency rate was 77.3% (17/22). In five patients 22% (5/22), this treatment was unsuccessful; thus another metallic stent was placed in two of these patients. On the other hand, in three patients, we opted for surgical treatment.Conclusion: To our knowledge, this series is the longest reporting the use of ureteral metallic stents for the treatment of ureteral stenosis after kidney transplantation. Ureteral metallic stents implantation is an effective alternative for the treatment of ureteral stenosis in patients with chronic graft dysfunction or high surgical risk.

C-602 Lumbosacral disc herniation: Spinal interventional chemonucleolysis with CT-intradiscal oxygen-ozone (O2-O3) mixture with intradiscal T. Angileri1, F. Verderame1, A. Taibbi2, T.V. Bartolotta2, M.A. Banco2, G. Sparacia2; 1Bagheria/IT, 2Palermo/IT (tommaso.angileri@libero.it)

Purpose: To evaluate the efficacy of treatment of lumbosciatalgia by means of CT-guided chemonucleolysis with oxygen-ozone mixture (O2-O3) with intradiscal, periradicular and periganglionic techniques.Methods and Materials: From January 1999 to January 2007, 778 patients (346 women, 432 men; age-range: 18-75 years) with lumbosciatalgia by disc herniation confirmed with CT and/or MR underwent intradiscal, periradicular and periganglionic treatments with O2-O3, corticosteroids and anaesthetics under CT guide. The analysis of the results was made by Visual Analogue Scale (VAS) 1 day before treatment (T0) and, respectively, 4 weeks (T1), 3 months (T2), 6 months (T3) later. All procedures were performed in a step-wise fashion and controlled by CT scans: from positioning the needle in the centre of the nucleus polposus to mixture admin-istration within the nucleus and in periradicular and periganglionic sites.Results: In 630/778 (81%) patients, a partial remission of the complaints just after the first treatment (VAS 6 at T1) was observed; VAS was 4 at T2 and 2 at the last evaluation, six months later (T3). In 104/778 (13.4%) patients, VAS was 8 at T1 and further treatment was performed. In 30/104 (28.8%) VAS improved at T2 and T3, respectively, up to 5 and 3 in 20/30 cases. The remaining 74/104 patients did not show any improvement even after the second treatment and VAS ranged from 8 to 10 at T3.Conclusion: Chemonucleolysis with oxygen-ozone mixture (O2-O3) with perira-dicular and periganglionic techniques under CT guidance is a reliable and competi-tive method in treatment of lumbosciatalgia.

C-603 Recurrent prostate cancer: A prospective study on the use of MR-guided galvano-therapy F.B. Mayer1, H. Mayer2, S. Zangos1, T. Vogl1; 1Frankfurt a. Main/DE, 2Regensburg/DE (florianmayer@gmx.ch)

Purpose: To determine the effect of MR guided galvano-therapy on recurrent localized prostate carcinomas.Methods and Materials: In this prospective study, we evaluated the results of MR guided galvano-therapy in 25 patients with histological proven diagnosis of recur-rent prostate cancer. The therapy was performed after patients got biopsy of the prescribed lesion to receive a histological proven diagnosis of recurrent prostate cancer. With this diagnosis, patients received galvano-therapy on an outpatient protocol three times with seven to ten days between each treatment. Three, six and twelve months post therapy patients got follow-up MRI volume measurements to assess developing of the disease.Results: All patients tolerated the MR guided galvano-therapy well without any major side effects or complications. 10 patients got a hormonal therapy, 10 pa-tients had surgery, 4 patients received surgery and radiation therapy and 1 got a HIFU. Pre-therapy median tumor volume was 2.1 ccm and in 12 month check up we detected measured a median volume of 1.1 ccm. The twelve month check up showed 18 cases with stable disease findings and 6 cases with partial remission findings and one with a complete remission finding. PSA values decreased from a pre-therapeutic median of 8.7 ng/ml to a value of 5.8 ng/ml (66.6%) after three months, to a value of 2.5 ng/ml (28.7%) after 6 months and finally to a median value of 1.1 ng/ml (12.6%) in the last check up.Conclusion: Galvano-therapy might be a dependable way to treat recurrent prostate carcinoma independent of the first therapy.

C-604 CT-guided fine-needle aspiration in spondylodiskitis: True usefulness of a common practice E. Sánchez, R. Pellón, L. Martin, J. Izquierdo, E. Marco de Lucas, G. Blanco, M. Pelaz, A. Gutiérrez, F. Quintana, E. Ruiz; Santander/ES (radmle@humv.es)

Purpose: To evaluate the diagnostic accuracy of computed tomography-guided fine-needle aspiration in diagnostic management of vertebral infections. To ana-lyze the main complications and influence of different variables including previous antibiotic treatment.Methods and Materials: A retrospective study of 77 confirmed spondylodiskitis of the thoracic and lumbar spine treated at our center between January 2000 and January 2007 and followed up over two years. Forty-two specimens were obtained using a CT-guided fine needle-aspiration (20 or 22G) in order to try to isolate the etiologic organism.

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Results: Analysis of the results showed a positive result in 18 cases (44%) of FNA performed, increased up to 60% when considered only patients without previous antibiotic treatment. M tuberculosis and S aureus were the most frequent agents encountered. 60% of cases with negative result have a previous antibiotic treatment. No major complications were observed.Conclusion: Computed tomography-guided FNA is an important and useful tool in the evaluation of spondylodiskitis. However, FNA rentability in spondylodiskitis might be lower than reported in previous series which included punctions of infections and also neoplasms. Previous antibiotic treatment has a major impact on final rentability of the procedure. M tuberculosis infections have a higher rate of positive cultures possibly associated with frequent paravertebral collections depicted in these cases.

C-605 Large HCC ablation by a new saline-enhanced expandable radiofrequency device L. Tarantino1, I.F.M. Sordelli2, V. Nocera1, A. Piscopo1, C. Ripa2, D. Parmeggiani2, P. Sperlongano2; 1Frattamaggiore/IT, 2Naples/IT (luciano_tarantino@fastwebnet.it)

Purpose: Evaluation of a new device designed for large volumes of necrosis by radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC).Methods and Materials: Twenty-nine consecutive patients with 31 HCC 3 cm in size (range 3-7.5 cm, mean 5.5 cm) underwent US-guided-percutaneous-RFA using an expandable electrode with seven active arrays and saline injection, designed to create tissue ablation up to 7 cm (StarBurst-XLi-enhanced, RITA Medical Systems. CA, USA). Treatments were performed in general anesthesia (6 patients) or deep sedation (23 patients). Treatment efficacy was assessed by three-phase-enhanced-CT and bimonthly US follow-up.Results: 1 to 5 electrodes’ insertions (mean 2.6) were performed per patient. Complete necrosis at CT was achieved in 23/31 HCC nodules (74%) in 22 patients. Follow-up of these 22 patients ranged from 2 to 15 months (mean 8.3 months). 6/22 (28%) patients showed new intrahepatic recurrences within 5-10 months (mean 8.3 months). Major complications were: post-ablation syndrome in 7/29 (24%), peritoneal effusion in 4/29 (14%), pleural effusion in 2/29 (7%) and transient obstructive jaundice in 1/29 (3.4%) patients. One patient died 6 months after treatment because of the tumor.Conclusion: For the treatment of large HCC, StarBurst-XLi-enhanced is an ef-fective and safe device.

C-606 Percutaneous radiofrequency thermal ablation (RFA) of renal tumors: Single center experience A. Ianniello, G. Carrafiello, D. Laganà, C. Recaldini, P. Nicotera, C. Fugazzola; Varese/IT (ianand@libero.it)

Purpose: To evaluate and discuss prognostic factors, efficacy and complications of percutaneous RFA in the treatment of renal tumors.Methods and Materials: Between January 2003 and August 2007, 20 patients affected by 21 kidney tumoral lesions, 20 RCC and 1 renal oncocitome (one patient was affected by two RCC), undergo 22 treatments of RFA (one patient underwent 2 treatments due to residual tumor). The lesions had a diameter between 1.5 and 5 cm (average 2.7 cm). Fourteen lesions were exophytic, 3/15 parenchymal, 2/15 was central while 2/15 was mixed. Sixteen lesions were treated under ultrasound guidance while 5 lesions under the CT guide.Results: The primary success of the treatment, assessed when CT or MRI per-formed after one month showed no enhancement or enlargement of the treated lesion, was obtained in 20/21 (95.2%). In 1/21 lesion (4.8%), a 5 cm mixed type lesion, an incomplete ablation was obtained; for this reason this patient underwent a second treatment and after 6 months of a regular follow-up, no more neoplastic tissue was identified. During the follow-up, there have no signs of the disease starting again in any of the patients. No major peri-procedural complications were recorded; in only one patient we observed the appearance of a peri renal liquid and a thin pneumothorax layer that resolved completely few days after the procedure.Conclusion: Preliminary results with RFA of RCC are promising. Radiofrequency ablation is not associated with significant side effects. Further follow-up is neces-sary to determine the long term efficacy of RFA.

C-607 Management of malignant hilar bile duct obstruction with biductal stent placement in Y configuration H.-P. Hong, H. Lim, S. Kim; Seoul/KR (hyojin78@samsung.com)

Purpose: To report the results of biductal stents placement in Y configuration in patients with malignant hilar bile duct obstruction.Methods and Materials: Self expandable metallic stents were placed percutane-ously in 41 patients with unresectable malignant hilar obstructions. The patients included 28 men, 13 women, with median age of 63 years. Two stents were placed through left and right hepatic ducts. The cause of bile duct obstructions were hilar cholangiocarcinoma (n =22), GB cancer (n =9), HCC (n =3), recurred CBD cancer (n =4) and metastatic lymphadenopathy (n =3). The type of hilar obstructions are cat-egorized in Bismuth type I (n =4), II (n =3), IIIa (n =11), IIIb (n =3) and IV (n =20).Results: Stents placement were technically successful in 40 patients (97%) and early clinical response was obtained in 39 patients (95%). Early major complica-tions were developed in 3 patient (7%), which were liver abscesses (n= 2) and pneumonia (n= 1). The total mean stent patency was 124 days and mean patient survival was 191 days. The patient with hilar cholangiocarcinoma showed the longest survival days (242 days) and patients with metastatic lymphadenopathy showed the longest primary stent patency (186 days). Among the type of obstruc-tion, patients with Bismuth type IV obstruction showed the longest primary stent patency (172 days).Conclusion: Biductal stents placement in Y configuration offers moderate results for palliation of malignant hilar bile duct obstruction. The patients with metastatic lymphadenopathy or Bismuth type IV obstruction showed longer primary stent patency.

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Molecular Imaging

C-608 Usefulness of MRI on evaluating hepatic distribution of Fe3O4 magnetic nanoparticles in an experimental model: Preliminary steps in magnetic hyperthermic treatment of hepatic tumours J.J. Echevarria1, R. Maniega1, I. Garcia-Alonso2, I. Aguirre1, J. Salado2, M. Insausti2, T. Rojo2, N. Etxebarria2, G. Arana2, F. Plazaola2; 1Galdakao/ES, 2Leioa/ES (FIZER@telefonica.net)

Purpose: Thermal ablation using magnetic nanoparticles, which develop hysteretic heating when exposed to an external magnetic field, represents a hypothetical treatment of tumours. As a previous step to the use in treatment of liver cancer, we have evaluated the ability of MRI on monitoring hepatic distribution of iron magnetic nanoparticles in an experimental model.Methods and Materials: Twelve WAG male rats were used, eight got samples with different concentrations of Fe3O4 nanoparticles (2-9 mg) dissolved in Lipiodol (0.3 ml) through ileo-colic vein, and four represented the control group. Twenty four hours after iron infusion, MRI was performed under light anaesthesia on a 1.5-T Siemens Symphony system. Standard cranial coil was used. Axial and coronal T1 (TR: 651/TE: 24) and GRE (120/5 and 163/14) weighted sequences were made. Finally, all rats were sacrificed to obtain liver tissue that was analyzed for iron content by spectrometry and for histological analysis.Results: On T1 sequences, hepatic tissue appears with signal intensity (SI) similar to muscle in all animals. On GRE sequences (especially on 163/14 sequences), substantial decrease in hepatic SI was viewed in animals with nanoparticles. The mean hepatic iron concentration in control group was 172 μg/g (range: 151-206) and in group with nanoparticles was 471 μg/g (range: 289-606). Around 50% of infused iron did not exit the liver. Histological analysis demonstrated no acute tissue response.Conclusion: Ferromagnetic particles suspended in lipiodol are trapped on hepatic sinusoids in a high ratio and can be accurately detected on MRI especially using GRE sequences.

C-609 The role of fused whole body FDG-PET/MRI images for evaluation of patients with cancer R.C. Domingues, M. Carneiro, L.C.H. da Cruz Jr, E.G. Antunes, E.L. Gasparetto, R.C. Domingues; Rio de Janeiro/BR (celsohygino@hotmail.com)

Purpose: To compare whole-body MRI with fluorine 18-fluorodeoxyglucose (FDG) PET and fused whole-body FDG-PET/ MRI for the evaluation of patients with cancer.Methods and Materials: We studied 18 patients with cancer who underwent whole-body MRI and FDG-PET for staging or follow-up post-treatment. After MRI and FDG-PET acquisition with standard techniques, whole body PET-MRI co-registration and image fusion were performed. Two experienced radiologists evaluated independently the whole-body MRI, the FDG-PET and whole-body fused FDG-PET/MRI, assessing the primary tumor, the presence of pathological lymph nodes and distant lesions. The number of lesions seen with each technique was compared.Results: All the primary lesions were evaluated similarly with the three techniques. Regarding the lymph nodes, which were seen in 12 cases, all the techniques had similar results in nine cases. In the remaining three cases, the PET did not identify the lesions in one case and the MRI did not observe the lesion in two cases. The distant lesions, seen in 11 cases, were well seen in all techniques in four cases. In other four patients, the PET did not demonstrate the lesions. In two cases, the MRI did not show the lesions, and in one case, one of the lesions was not seen on the PET and one lesion was not observed on the MRI (bone lesion).Conclusion: The fused whole-body PET-MRI is a useful imaging technique for the assessment of follow-up and staging of patients with cancer, being superior to whole-body MRI and FDG-PET as isolated methods.

C-610 Imaging angiogenesis with an endothelin-receptor affine fluorescent photoprobe C. Hoeltke, J. Waldeck, K. Kopka, M. Schaefers, W.L. Heindel, C. Bremer; Muenster/DE

Purpose: The endothelin-A receptor (ETAR) is known to be involved in tumor angiogenesis. Clincal data suggests that a high expression of ETAR is linked to a poor clinical outcome. The developed photoprobe provides the possibility for in vivo visualization of ETA receptors in affected tissue.

Methods and Materials: Based on the highly affine and selective endothelin-A receptor antagonist PD 156707, a novel fluorescent photoprobe for the imaging of ETAR was developed (ETAR-Cy 5.5). The affinity of ETAR-Cy 5.5 to ETAR-positive MCF-7 cells and ETAR-negative MDA-MB 435 cells was evaluated by fluorescence microscopy. In vivo experiments using fluorescence mediated tomography (FMT) in murine xenograft models were performed. Western blot analysis was used to identify protein expression of cells and tumor tissue.Results: While in vitro cell binding assays showed high fluorescence on ETAR-posi-tive MCF-7 cells, ETAR-negative MDA-MB 435 cells showed little to no fluorescence signal, corroborated by western-blotting. In vivo imaging of tumor xenografts showed high fluorescence for both MDA-MB 435 and MCF-7 tumors. Protein expression analysis of tumor tissue revealed that in MDA-MB 435 xenografts mainly murine ETAR is present while in MCF-7 xenografts the human and murine form of ETAR is found.Conclusion: The synthesized conjugate ETAR-Cy 5.5 can be used to visualize ETAR expression in vivo. In murine xenograft models, the tracer visualizes ETA receptors on both tumor tissue and sprouting angiogenic host blood vessels. This approach may be applicable for the imaging of angiogenesis and anti-angiogenic therapies.

C-611 Somatostatin receptor status and glucose metabolism in neuroendocrine tumours: Intra-individual comparison by Ga-68-DOTA-NOC PET/CT and F-18-FDG PET/CT S.W. Oh1, V. Prasad2, D.S. Lee1, R.P. Baum2; 1Seoul/KR, 2Bad Berka/DE (info@rpbaum.de)

Purpose: To study the relationship between somatostatin receptor (sstr) expres-sion and glucose metabolism in metastasised neuroendocrine tumours (NET), and to investigate if there is a difference in response to peptide receptor radionuclide therapy (PRRT) in hypermetabolic metastases without sstr expression (flip-flop phenomenon).Methods and Materials: In 25 patients (57.5 13.4 years) with metastasised NET, both Ga-68-DOTA-NOC and F-18-FDG-PET/CT were performed within 3 days pre PRRT (up to 3 cycles). A maximum of 5 lesions per organ/10 lesions in total were chosen for the quantitation of the maximum standardised uptake values (SUVmax), comparing group A (matched lesions, i.e. +ve on both SMS and FDG) and group B (mismatch, i.e. +ve on SMS and -ve FDG or vice versa.Results: Baseline SUVmax of Ga-68-DOTA-NOC in GrA (n=77, 22.6 13.8) was higher than in GrB (n=54, SUVmax 14.1 8.9, p=0.001). After PRRT, SUVmax of Ga-68-DOTA-NOC decreased in both groups, regardless of the FDG uptake (GrA; 17.0 9.3, p 0.0001: GrB; 11.5 8.3, p=0.0001). However, FDG-SUVmax decreased in GrA (n=77, 8.9 4.3 vs. 6.6 4.1, p 0.0001), whereas FDG-uptake in GrB increased (n=7, 10.3 4.8 vs.14.8 6.1, p=0.046). FDG picked up 7/138 (5%) additional lesions and missed 54/138 (39%).Conclusion: In NET, sstr status and glucose metabolism are independent pa-rameters. Patients with receptor negative, FDG positive metastases (mismatch) showed a poorer response to PRRT. Disease progression despite a decrease of sstr positive lesions (receptor/metabolism flip-flop) may be attributed to tumour cell clones with different biological behaviour.

C-612 Assessment of treatment effects by bioluminescent imaging (BLI) and micro-CT in a mouse bone metastasis model E. Stepina, A. Strube, S.-M. Kaekoenen, P. Hauff; Berlin/DE (elizaveta.stepina@bayerhealthcare.com)

Purpose: Animal models play an important role in the development and evaluation of new anti-cancer drugs. The aim of the study was to investigate the therapeutic effect of a fully synthetic epothilone (sagopilone (ZK-EPO)) and paclitaxel on es-tablished osteolytic bone lesions at morphological and molecular levels in a mouse model of breast cancer bone metastasis.Methods and Materials: Female nude mice were inoculated with MDA-MB-231 (SA)/luciferase breast cancer cells in the left cardiac ventricle (day 0). Osteolytic bone metastases were developed 3-4 weeks after intracardiac inocula-tion. The therapeutic effect of sagopilone (10 mg/kg, one injection on day 13, i.v). or paclitaxel (9 mg/kg, once daily on days 13-17, i.p). treatment on bone lesions was determined by micro-CT and X-ray on day 22. The total bone volume of tibia and femur was calculated from micro-CT-images. The spread of cancer cells was monitored using BLI.Results: The localization of tumor cells detected by BLI in limbs, calvaria, spine, hips and scapula correlated with the localization of osteolytic lesions identified by micro-CT and radiography. Determination of bone volume of femur and tibia revealed a significant reduction of bone lesions of sagopilone and paclitaxel treated animals

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compared to the vehicle group. The bone destruction observed in the sagopilone group was significantly less compared to the paclitaxel group.Conclusion: The combination of BLI and micro-CT allows a simultaneous monitor-ing of tumor cell localization and morphological changes of bones. The estimation of bone volume allows not only qualitative, but also quantitative analysis of osteolytic changes in bones.

C-613 Changes in the integrin receptor availability of human adult mesenchymal stem cells after labeling with superparamagnetic iron oxide R. Kehlbach, R. Schäfer, E. Scheer, T. Kluba, R. Bantleon, C.D. Claussen, J. Wiskirchen; Tuebingen/DE (jakub.wiskirchen@med.uni-tuebingen.de)

Purpose: To evaluate the influence of small particles of iron oxide (SPIO) labeling on the integrin receptor availability of bone marrow derived human adult mesen-chymal stem cells (MSC) directly after the labeling procedure and two passages after labeling.Methods and Materials: Adult MSC were isolated from the bone marrow of five patients undergoing orthopaedic operations. The MSC were characterised by in vitro differentiation assays and analysis of the surface epitope pattern. The MSC were labeled with 200 μg/ml SPIO (Resovist®) or with 60μg/ml SPIO in combination with the transfection agents (TAs) Dosper®, PULSin™ or jetPEI™. The surface receptor expression of integrins ( 1 CD29, 1 CD49a, 4 CD49d and 5 CD49e), Endoglin (CD105) and H-CAM (CD44) was analysed by FACS directly after the labeling procedure and two passages after labeling. Spectrophotometrically, quantification of the cellular total iron load (TIL) and determination of the cellular viability were performed additionally.Results: Labeling of MSC with SPIO was feasible without affecting cell viability or their adipogenic, osteogenic or chondrogenic differentiation potential. SPIO labeled MSC showed a decline in availability of all investigated markers directly after label-ing. Two passages after the labeling these effects are no longer apparent indicating a short-term or medium-term covering of the cell surface by the treatment.Conclusion: SPIO labeling may have a biological impact on MSC adhesion or homing characteristics directly after the labeling by at least partially masking the respective receptors or proteins. The plasticity of the cells is not affected.

C-614 Monitoring response to peptide receptor radionuclide therapy (PRRT) in patients with metastasised neuroendocrine tumours (NET): Intraindividual comparison between Ga-68-DOTA-NOC, F-18-FDG-PET/CT, and CT alone S.W. Oh1, V. Prasad2, D.S. Lee1, R.P. Baum2; 1Seoul/KR, 2Bad Berka/DE (info@rpbaum.de)

Purpose: To evaluate the role of Ga-68-DOTA-NOC somatostatin receptor PET/CT in the assessment of response to PRRT (SSR-PET, “molecular response”) in comparison with F-18-FDG-PET/CT (FDG, “metabolic response”) and contrast enhanced CT alone (ceCT, “morphologic response”).Methods and Materials: In 25 patients (57.5 13.4 years) with metastasised NET, 138 discrete lesions were analysed pre and post treatment (up to 3 cycles) by SSR-PET, FDG and ceCT alone. For ceCT, RECIST criteria were used, for SSR-PET and FDG modified EORTC criteria were applied. Maximum standardised uptake values (SUVmax) for all lesions and normal liver tissue were obtained. For each lesion, the Response Index (RI= 100x [(post-PRRT SUVmax)-(pre-PRRT SUVmax)]/pre-PRRT SUVmax) was calculated. In addition, the ratio of SUVmax of metastatic liver lesions to normal liver tissue was calculated for ROC. SD, PR, and PD were determined for therapy response assessment.Results: There was no significant correlation amongst the three different modalities. Molecular response (correlating with clinical/biochemical improvement) was seen on SSR-PET/CT in 13 patients (PR 60%, SD 24%, PD 16%), metabolic response on FDG PET/CT in 6 patients (PR 36%, SD 55%, PD 9%), whereas ceCT alone showed either SD (64%) or PD or PR (16% each). Keeping the cut-off value of SUVmax 2.5, it was possible to predict the response of liver lesions to PRRT with a sensitivity of 88.9% and a specificity of 71.4%.Conclusion: Ga-68-DOTA-NOC-SMS-receptor-PET/CT is superior to ceCT for the early assessment of response to peptide receptor radionuclide therapy in metastatic NET (“molecular response precedes morphology”).

C-615 Fluorescence labelled barbiturates as novel non-peptidic MMP-2 and -9 optical imaging agents B. Waschkau, A. Faust, H.-J. Breyholz, J. Waldeck, K. Kopka, M. Schaefers, C. Bremer; Muenster/DE (biancawaschkau@gmx.de)

Purpose: Imaging upregulated matrix metalloproteinases (MMPs) representing one of the key players in oncogenesis is highly desirable.Methods and Materials: In this study, C-5-substituted barbiturates which exhibit high binding affinities for gelatinases A (MMP-2) and B (MMP-9) were modified in order to obtain a target specific, non-peptidic optical MMP inhibitor (MMPI-Cy5.5) as a tool for in vivo imaging of MMP activity. Various tumor cell lines were characterized for MMP-2/-9 expression via PT-PCR and western blotting. Furthermore, enzyme inhibition and target binding of MMPI-Cy5.5 were evaluated.Results: A convergent overall ten step synthesis was developed to generate the MMPI-Cy5.5. To minimize the interactions between the activated MMP and the dye, a pegylated spacer was installed yielding a non-hydroxamate MMPI with IC50-values of 27 nm (MMP-2) and 138 nm (MMP-9). Zymography revealed an efficient blocking of enzyme acitvity of purified MMP-2 and of MMP-containing cell supernatants (HT-1080, HTB-56) using 50 μM of the unlabelled barbiturate. Fluorescence microscopy revealed strong binding of the probe by MMP positive cells while MMP negative cells and predosing with the non-labelled ligand revealed little to no fluorescence.Conclusion: The new non-peptidic barbiturate-based MMP-probe exhibits high binding affinity to MMP-2 and -9 in vitro and is thus a promising candidate for sensitive MMP detection in vivo.

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C-616 MR imaging in bone sarcomas in children: Pre- and post-treatment imaging features M. Jastrzebska, A. Romaniuk-Doroszewska, H. Brogoszewska, M. Bekiesinska-Figatowska; Warsaw/PL (jastrzebska_m@yahoo.com)

Learning Objectives: 1. To review the MR imaging findings in bone sarcomas: osteosarcoma, Ewing sarcoma, chondrosarcoma. 2. To learn evaluation of tumor stage and response to neoadjuvant chemotherapy (chth) 3. To describe postopera-tive and post- radiotherapy (rth) changes.Background: Osteosarcoma and Ewing sarcoma are the most common bone sarcomas in children, accounting for 7% of all malignant tumors in children. MRI is the most important imaging modality for evaluation of the extension of tumor and monitoring therapy. Multi-agent chemotherapy improved the results of treatment, long-life prognosis and extremity salvage operations. Over 100 MR examinations were performed with use of a 1.5 T scanner in 56 children with histologically proved osteosarcoma (n=24), Ewing sarcoma (n=25), chondrosarcoma (n=7) in various periods of treatment.Imaging Findings: MR images during following periods will be presented: 1. diagnostic period - signal intensity in different sequences and typical appearance of bone sarcomas. 2. after chth, before surgery - tumor response, tumor extension and measurements to assess response to therapy and to establish surgery strategy. 3. follow-up after surgery and/or rth - post-therapy changes, local recurrence, skip metastases. MRI is very accurate in estimation of the stage of the tumor: bone marrow extension and surrounding structures involvement. The interpretation of MRI in follow-up studies after rth is difficult, and the knowledge of evolution of post-radiation changes over time is essential.Conclusion: MR imaging is the modality of choice in the assessment and staging of bone sarcomas. MRI has great value in monitoring response ro chth or rth and evaluating surgery outcome.

C-617 Lytic epiphyseal lesions: Is it possible to reach the correct diagnosis? M. Seco, B. Graça, B. Gonçalves, A. Peres, F. Caseiro-Alves; Coimbra/PT (migseco@sapo.pt)

Learning Objectives: To learn the differential diagnosis of a lytic epiphyseal lesion.Background: A lytic epiphyseal lesion is an occasional problem for the skeletal radiologist. The differential diagnosis is relatively short. However, it includes not only neoplastic pathology like giant cell tumor, chondroblastoma, metastases, myeloma and aneurysmal bone cyst but also non-tumoral pathology including osteomyelitis, eosinophilic granuloma and subchondral cyst. The epiphyseal differential tends to work also for the tarsal bones, carpal bones, patella and apophyses.Imaging Findings: Several lytic epiphyseal lesions, including giant cell tumor, chondroblastoma, metastases, myeloma, aneurysmal bone cyst, osteomyelitis, eosinophilic granuloma and subchondral cyst, will be illustrated using various imaging modalities. Clinical presentation and imaging features of each entity will be analyzed for its contribution for the differential diagnosis.Conclusion: Imaging features when correlated with clinical presentation (including age) will make possible that most of the time we can do the exact diagnosis of a lytic epiphyseal lesion.

C-618 Surface lesions of bone S. Chaabane, M. Chelli Bouaziz, A. Ben Hassine, D. Kaffel, M. Ladeb; Tunis/TN (skanderchaabane@yahoo.fr)

Learning Objectives: The aim of this pictorial review is to illustrate the imaging features of various bone surface lesions.Background: Surface lesions of bone may arise between the cortex and the peri-osteum, within the inner or the outer layers of the periosteum. Such lesions may be of neoplastic, traumatic or infectious origin. While some surface lesions have a classic appearance at imaging similar to their intramedullary counterparts, many are non specific. Correlation with clinical information and laboratory data can be helpful. However, sometimes biopsy is the unique method to establish final diagnosis.

Procedure Details: It is a retrospective study of surface bone lesions seen at our institution during the last ten years. Most demonstrative cases were selected. All imaging features that may suggest specific diagnosis are discussed according to radiography, bone scintigraphy, ultrasound, CT and MRI. Clinical, biological and histological data were also reviewed.Conclusion: Physicians and radiologists should be familiar with the entire spectrum of surface lesions in order to avoid misdiagnosis.

C-619 The accessory navicular syndrome: Imaging features with emphasis on magnetic resonance imaging N. Doda, W.C.G. Peh; Singapore/SG (wilfred.peh@gmail.com)

Learning Objectives: To know the classification of accessory naviculars. To understand the pathophysiology and know the clinical features of the accessory navicular syndrome. To recognize the imaging, particularly MR imaging, features of the accessory navicular syndromeBackground: The accessory navicular is a relatively common congenital anomaly of the foot that arises from an accessory ossification center. Accessory navicular is classified into types I, IIa, IIb and III. Occasionally, these become symptomatic and can present with acute or chronic foot pain, giving rise to the accessory na-vicular syndrome. Among the theories for pathophysiology of this syndrome, the four commonest are: pressure secondary to bony prominence, abnormal midfoot biomechanics, trauma to synchondrosis or posterior tibialis tendonitisImaging Findings: Although these anomalous bones can be identified on radio-graphs, they are not able to provide a definite diagnosis of the accessory navicular syndrome. Bone scintigraphy may show increased uptake on the symptomatic side, but lacks specificity as asymptomatic bones may also show focal uptake. MR imag-ing is a valuable diagnostic tool for the assessment of a symptomatic accessory bone. MR images typically display a bone marrow edema pattern on the symptom-atic side, indicative of a stress reaction. It is also useful in evaluating associated injury to the posterior tibialis tendon. MR imaging provides useful information for further management of the patient, which may be conservative or surgical.Conclusion: Imaging, particularly MR imaging, has an important role in the diag-nosis and management of the accessory navicular syndrome.

C-620 Osteosarcoma: Spectrum of radiological appearances A. Malik, B. Thukral, G. Khanna, R. Prasad; New Delhi/IN (amitamalik@yahoo.com)

Learning Objectives: To illustrate the spectrum of radiological appearances in osteosarcoma.Background: Osteosarcoma is the most common primary malignant bone tu-mour in adolescents and young adults.The primary osteosarcomas are broadly categorised into intramedullary, surface and extraskeletal types. Osteosarcoma may occur as a secondary lesion in association with underlying benign condition or may be radiation induced.As with most osseous lesions, differential diagnosis is developed using the patient’s age, location of lesion within the skeleton and the particular bone and, most importantly, the radiographic appearance. Computed tomography and magnetic resonance imaging are used primarily for staging.The former with its ability to dem-onstrate subtle matrix mineralization can be problem solving in difficult cases.Imaging Findings: Our exhibit is based on the radiographic findings in 48 patho-logically confirmed osteosarcomas. There were 34 males (71%) and 14 females (29%) with an age range of 8-54 years.The long bones of the lower limb were more commonly involved than those of the upper limb. The typical location was the meta-diaphyseal region. Flat bones were involved in 6.2%. Radiographs showed varied appearances like aggressive bone destruction, a wide zone of transition, matrix mineralization, cortical thickening, elevation of periosteum in the form of Codman’s triangle and sunray spicules, and extension into soft tissues.Conclusion: The radiological appearances of osteosarcoma vary over a wide spectrum. These are often characteristic for each type and thus suggestive of the specific diagnosis. Additional modalities like bone scintigraphy, and CT and MR examination provide vital information for preoperative staging.

C-621 Osteoblastic bone metastases: How to crack a tough nut T. Moser, X. Buy, J.-L. Dietemann, A. Gangi; Strasbourg/FR (afshin.gangi@chru-strasbourg.fr)

Learning Objectives: To describe the complete radiological management of osteoblastic bone metastases with both diagnosis and treatment.

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Background: Osteoblastic bone metastases are less common than their osteo-lytic counterparts and their management has not received much attention in the radiological literature. However, they pose specific problems in terms of diagnostic imaging and image-guided treatment.Imaging Findings: We review the principal etiologies and physiopathology of os-teoblastic metastases, present their appearance with different imaging techniques, including nuclear medicine, and their differential diagnosis. We also describe the technique and specific material used for the biopsy of such lesions. Finally, we discuss and illustrate the respective indications of low power radiofrequency abla-tion, cryoablation and cementoplasty for pain relief, depending on the density and topography of the lesions.Conclusion: Osteoblastic bone metastases pose specific problemes in terms of diagnosis and treatment, but the radiologist has an important role to play in their management.

C-622 Fractures of the fifth metacarpal T.E. Gudmundsen, L. Borgen; Drammen/NO (tor.erik.gudmundsen@sb-hf.no)

Purpose: Epidemiological aspects of fractures of the fifth metacarpal are sparsely dealt with in the literature. The present study explores the incidence and various types of such fractures and how it is related to age, gender and weekday of injury.Methods and Materials: All fractures of the hand diagnosed at the Department of Radiology, Central Hospital of Buskerud, Norway, from 2004 to 2006 were studied.Results: Of a total of 1475 fractures of the hand, 271 (18.4%) were located in the fifth metacarpal. In 130 of these cases (121 males, 9 females), the injury had occurred during aggression such as a fistfight or from punching a hard object. The majority of these fractures were located in the neck of the metacarpal (Boxer’s frac-ture). The median age of this group was 22 years, ranging from 7 to 51 years. 95 of the 130 fractures seen after aggression occurred during weekends. More than half of all the fifth metacarpal fractures, 141 of 271, were caused by accidental trauma (104 males, 37 females, median age 34 ranging from 2 to 90 years). In this group, the fractures were nearly equally found in the subcapital, diaphysal and basal part of the metacarpus, and no specific pattern as to day of the week could be seen.Conclusion: Of all fractures of the hand, the fifth metacarpal is most often fractured. Nearly half of such fractures are encountered during aggressive behaviour. The typical patient is a young male getting a subcapital fracture during the weekend.

C-623 Dynamic videofluoroscopic assessment of scaphoid non-union in decision finding for surgical therapy K. Holzapfel, K. Werber, E.J. Rummeny, C. Hannig; Munich/DE (holzapfel@roe.med.tum.de)

Purpose: To evaluate the use of videofluoroscopy for the differentiation of three types of scaphoid non-union: (1) completely stable (fibrotic) scaphoid non-union in which conservative treatment is possible, (2) partially stable (elastic fixation) and (3) completely instable scaphoid non-union that require surgical intervention.Methods and Materials: Videofluoroscopy was performed in 117 patients with scaphoid non-union demonstrated by plain radiographs. All patients performed the same maneuvers to ensure standardized examinations. After fixation of the forearm in a neutral position, active and passive radio-ulnar and dorso-palmar movement of the wrist was recorded in anterioposterior (a. p). and lateral views. Scaphoid non-union was considered stable when no movement between the fragments was observed. Partially stable scaphoid non-union was defined as varying distances of connected fragments during motion. In instable scaphoid non-union no functional connection during movement was seen. Images were analyzed by an experienced radiologist in slow motion and frame-by-frame modus. Imaging findings were cor-related with findings of wrist arthroscopy and/or surgery in all patients.Results: At arthroscopy and/or surgery, 42 scaphoid non-unions were stable, 22 were partially stable and 53 were completely instable. Of the 42 non-unions consid-ered stable, 41 were correctly classified by videofluoroscopy resulting in a positive predictive value (PPV) of 97.6%. Whereas all 53 instable scaphoid non-unions were diagnosed correctly (PPV 100%), one of the 22 partially stable scaphoid non-unions was considered instable in fluoroscopy (PPV 95.5%).Conclusion: Dynamic videofluoroscopic assessment of the wrist is a reliable tool in differentiating stable from partially or completely instable scaphoid non-union.

C-624 Spectrum of imaging findings in suspected multiple myeloma using dynamic contrast-enhanced and whole body MRI N. Herregods, K. Verstraete, S. Van Snick, K. Gorleer, V. Van Hende, L. Noens, F. Offner; Ghent/BE (nele_herregods@pandora.be)

Purpose: To assess the imaging findings in suspected multiple myeloma (MM) using dynamic contrast-enhanced and whole body MRI.Methods and Materials: 54 patients with suspected or known MM or monoclonal gammopathy of unknown significance (MGUS) were examined with coronal and axial T1 and fat suppressed T2 images from head to knee and with sagittal images of the whole spine. A dynamic contrast enhanced MRI of the thoracolumbar spine was performed using a single slice snapshot sequence (TURBO-FLASH) with a temporal resolution of 1 s/image, during the first 2 minutes after bolus injection of Gd-DTPA, with evaluation of the perfusion of the aorta, vertebrae and muscle.Results: We provide a pictorial review of: 1. The appearance of bone marrow in normal individuals, MGUS and anemic patients. 2. The appearance of bone marrow in MM (patterns of involvement - focal, mixed or complete). 3. The signs of (non)response to treatment in MM (resolution or size reduction of lesions, replacement by fatty marrow and growth). 4. Mimics resembling MM (e.g. after bone marrow stimulation). 5. Dynamic contrast-enhanced MRI of the thoracolumbar spine (time-intensity curves, normal findings, MGUS, MM before and after treatment, with examples of response and non-response). 6. Incidental findings (avascular necrosis and bone marrow infarction, osteo-articular lesions, abdominal and head and neck abnormalities, venous impulse due to coil compression, subcutaneous edema, etc.).Conclusion: There is a large spectrum of imaging findings in MM. Dynamic con-trast-enhanced MRI and whole body MRI are useful for investigation of patients with suspected MM or MGUS.

C-625 MR elastical characterization of trabecular bone relates to bone volume ratio and is influenced by gender L. Marti-Bonmati, A. Alberich-Bayarri, D. Moratal, R. Sanz-Requena; Valencia/ES (luis.marti@uv.es)

Purpose: In vivo structural and mechanical characterization of trabecular microar-chitecture is needed to characterize trabecular bone disease. We have evaluated the elasticity module with high resolution isometric 3D MR images of the wrist. Gender influence and the relationship between this module and the bone volume ratio are evaluated.Methods and Materials: 3 T MR images from 40 healthy subjects (21 women, 19 men; paired to age) were obtained. High spatial resolution (180 microns) was achieved with good contrast between voxels, and a satisfactory signal-to-noise ratio and a clear differentiation between cortical and trabecular bone. Images were pre-processed with automated trabecular bone segmentation and application of image processing algorithms (subvoxel processing, bone volume fraction map). On the structural analysis, the bone volume to total volume ratio was calculated. Mechanical simulation of the cancellous bone microarchitecture was done by the application of the finite element method in the compression case. After the homogenization theory was applied by postprocessing of the reaction forces and the displacements results, the apparent Young modulus of the whole structure was obtained.Results: Significant differences were found between male and female results for the Young moduli (p=0.012), being greater in men. A statistically significant correlation between elastic moduli and the square of bone volume to total volume fraction was detected for male (r2=0.899) and female (r2=0.964) subjects.Conclusion: Elastical characterization of MR obtained trabecular bone structures shows a relationship with the bone volume ratio and gender. As a biomarker, this analysis may advance our knowledge of cancellous bone quality.

C-626 Ewing’s sarcoma: Imaging features B. Peersman1, F.M.H.M. Vanhoenacker1, P. Brys2, M. Stam3, K. Verstraete4, B. Van Herendael1, S. Heyman1, P. Van Dyck1, P.M. Parizel1, A.M. De Schepper1; 1Antwerp/BE, 2Leuven/BE, 3Leiden/NL, 4Ghent/BE (filip.vanhoenacker@telenet.be)

Purpose: To define an imaging prototype of Ewing’s sarcoma (ES).Methods and Materials: 64 patients with ES were analyzed for age, gender and location. Matrix, margins, periosteal reaction, articular extension and presence of a pathologic fracture were evaluated on radiographs/CT. Size, local extension, signal intensity, enhancement pattern, and presence of skip metastases were evaluated on MRI. Distant metastases were recorded on bone scintigraphy and chest CT.

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Results: Patients’ age ranged between 7-67. Male/female ratio was 2.4/1. Pelvic location was most frequent (31%), followed by the femur (20%) and tibia (11%). 75 % of the tumors were mixed lytic-sclerotic, and lytic in 25%. Plain films and CT scan showed a spiculated periosteal reaction in 50%. A Codman’s triangle was seen in 27%. Cortical permeation and destruction was seen in respectively 31 and 42%, whereas cortical thickening was seen in 20%. Pathologic fracture occurred in 7.8%. Signal intensity and enhancement pattern were non-specific. MRI showed a large mass, with a soft tissue component of more than 50% in 67%. Joint involve-ment was seen in 23%. Isolated involvement of the soft tissue (extraskeletal ES) was seen in 1.5%. Skip metastases and distant metastases at initial presentation were present in 14% and 22% respectively.Conclusion: 1. On radiographs/CT, 37.5% are located in the axial skeleton and 62.5% in the peripheral skeleton. 2. ES is mostly mixed sclerotic-lytic. A spiculated periosteal reaction is most frequent. 3. The most characteristic finding on MRI is the presence of a large soft tissue mass.

C-627 Missed fractures in the emergency department: A structured review of the literature A. Pinto, M. Scaglione, A. Sparano, F. Di Pietto, G. Tortora, G. Russo, L. Romano; Naples/IT (antopin1968@libero.it)

Purpose: To review the pertinent literature in order to analyse fractures missed at conventional radiography in the emergency department and factors responsible for diagnostic failures.Methods and Materials: A recent Medline search on “fractures and missed diag-nosis” found a total of 728 articles. Sixty-two of them containing in the abstract also the words “plain radiography and emergency department” were selected. Patient’s age and factors affecting the accuracy of diagnosing fractures, such as imaging quality, insufficient clinical information and fracture type were reviewed.Results: The major rate of the missed fractures occurred in patients under 14 years of age. Most missed fractures in children were at the elbow and wrist; most missed fractures in elderly people occurred at the hip, including femoral neck and intertrochanteric fractures. Factors contributing to missed fractures were: critical and uncooperative patients, inadequate clinical examination, lack of relevant clinical information, inadequate or misinterpreted or not performed plain radiographs.Conclusion: Missed diagnosis of fracture may result in delayed treatment and unfavorable outcome for patients treated in the emergency department. It is also one of the most common causes leading to medical legal claims.

C-628 Augmentation of cortical bone mineral density in women with polycystic ovary syndrome (PCOS): A peripheral quantitative computed tomography (pQCT) study A. Balanika, C. Baltas, T. Spyridopoulos, O. Papakonstantinou, D. Loggitsi, M. Mademli, E. Trakakis, A. Gouliamos; Athens/GR (mpaltas@hotmail.com)

Purpose: Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by oligomenorrhoea/amenorrhoea, hyperandrogonemia and poly-cystic ovaries. The aim of this study was to estimate the influence of oestrogen deficiency and androgen excess on bone mineral density and bone strength in young oligomenorrhoeic/hyperandrogenic PCOS women using peripheral quantita-tive computed tomography (pQCT).Methods and Materials: Nineteen non obese PCOS young women with oligo-menorrhoea and hyperandrogonemia (aged 23 to 31 years old) underwent pQCT scans to determine total bone cross-sectional area (ToA), cortical area (CoA), cortical density (CtD), trabecular density (TtD), and stress-strength index (SSI) at the distal tibia. Their data were compared with those obtained from a control group of nineteen healthy women with normal ovulatory function matched for age and body-mass index (BMI) who underwent the same evaluation.Results: Compared with the controls, PCOS women had higher CtD (p 0.05). There were no significant differences in TtD, SSI, ToA and CoA values comparable to those of controls.Conclusion: Our results indicate that PCOS is associated with higher cortical bone mineral density at the distal tibia, probably through an osteoprotective effect of hyperandrogenism on cortical compartment of bone.

C-629 Post-surgical control after osteosynthetically treated fractures of the distal radius by means of multislice-CT M. Lorenzen, U. Wedegärtner, C. Weber, G. Adam, J. Lorenzen; Hamburg/DE (mlorenze@uke.uni-hamburg.de)

Purpose: Evaluation of the influence of the Multislice-CT (MSCT) in the post-surgi-cal control of osteosynthetically treated fractures of the distal radius.Methods and Materials: In 131 patients (median 48 years) with osteosyntheti-cally treated intraarticular fractures of the distal radius, conventional X-rays and an MSCT (Somatom plus volume zoom, Siemens 120 kV, 70 mAs, collimation 4x1 mm, pitch 1.25) have been performed. Axial, coronal and sagittal multi-planar reconstructions (MPR) were calculated from raw data sets using a high-resolution kernel with a slice thickness of 3 mm. Two radiologists compared the position of the osteosynthetic material and osseous elements on both the conventional X-rays and MSCT images.Results: Conventional X-rays and MSCT showed concordance concerning the location and position of the material in 73/131 patients. A large steplike off-set 3 mm was observed in 38/131 patients in conventional X-rays and in 15/131

patients in MSCT. In one patient, an intraarticular bone fragment was found in X-ray and MSCT in concordance. In three patients, an intraarticular position of osteosynthetic material suspected in X-ray was ruled out in MSCT thus avoiding surgical revision. In 42/131 patients, a dehiscence of the fragments of more than 2 mm was diagnosed with the MSCT which were not visualised by X-ray leading to surgical revision confirming the diagnosis in two patients.Conclusion: MSCT substantially adds to the diagnostic accuracy in postsurgical evaluation of patients with fractures of the distal radius.

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C-630 Noninfectious synovial proliferative processes: State-of-the-art MR imaging M.A. Santana Garcia, M.S. Garrido Carrasco, E. Alventosa Fernandez, M.C. Gonzalez Gonzalez, A. Bello Baez, M. Fernandez Del Castillo Ascanio; Santa Cruz de Tenerife/ES (angelesantana_23@hotmail.com)

Learning Objectives: Our objective is to show the typical imaging findings of the non-infectious synovial proliferative processes.Background: Intraarticular masses can be classified into several groups. One of these groups is the noninfectious synovial proliferative processes: lipoma ar-borescens, synovial osteochondromatosis, pigmented villonodular synovitis, and rheumatoid arthritis.Procedure Details: We have selected cases of these diseases and detailed their typical imaging findings mainly on magnetic resonance images (MRI), which can allow for a differential diagnosis between such entities and with other intraarticular masses. We have also made a literature revision about the general typical features of each one.Conclusion: Many of the diseases causing intraarticular masses have specific imaging characteristics, especially on MRI, that allow for a confident diagnosis.

C-631 Tumours and tumour-like lesions of the intercondylar notch of the knee: A pictorial review A.M. Davies, M. Christie-Large, P.K.L. Li, S.L.J. James; Birmingham/UK (amarkdavies@yahoo.co.uk)

Learning Objectives: To illustrate the range of tumour and tumour-like conditions that occur in the intercondylar notch of the knee.Background: The intercondylar notch of the knee describes an anatomical region that contains the cruciate ligaments, posterior attachment points of both menisci and a number of accessory ligaments. Various pathologies may arise in this loca-tion and the imaging features often allow a specific or limited differential diagnosis to be suggested. Most commonly lesions relate to the synovial lining of the joint capsule and the cruciate ligaments.Imaging Findings: MR imaging is the technique of choice in evaluating these conditions. Correlation with plain films or CT is important as the presence of hy-pointensity in the synovium on T2W sequences can be due to calcification, fibrosis or haemosiderin. IV gadolinium is useful in differentiating cystic lesions from solid tumours and synovial proliferation. It also demonstrates the extent of synovial proliferation in the presence of a joint effusion.Conclusion: There is a wide variety of tumour and tumour-like conditions that occur in the intercondylar notch of the knee, such as PVNS, meniscal cysts, syno-vial haemangiomas, lipomas and sarcomas. These can usefully be grouped into synovial disorders, benign tumours, malignant tumours, cystic lesions and extrinsic masses. The MR imaging features of each group is by no means specific but, by correlating with history, plain films and the use of a contrast medium, a narrow list of differential diagnoses can be given.

C-632 Diagnostic imaging of patello-femoral incongruence G. Valeri, A. Quagliarini, B. Simonetti, A. Gigante, S. Ulisse, A. Giovagnoni; Ancona/IT

Learning Objectives: To explain and discuss the techniques and methodologies of the imaging procedures in patients with patello-femoral incongruence.Background: Patello-femoral malalignament is more frequent in young female patients and is the most frequent cause of anterior knee pain. Diagnosis of patello-femoral incongruence, in addition to clinical signs, depends on conventional radiography, dynamic CT and MRI with and without quadriceps contraction and arthroscopy.Imaging Findings: The role, techniques and evaluation methods of conventional radiography and of dynamic CT and MRI will be discussed. In particular, the various angles and measurement achievable with conventional radiography, CT and MRI will be explained and compared.Conclusion: The conventional radiography plays still a role in the evaluation of the patello-femoral incongruence but the best diagnostic methods are dynamic CT and MRI. Recently, vertical MRI has been used in order to evaluate the gravitational modifications in the patello-femoral incongruence.

C-633 A pictorial essay of MRI follow-up of the ankle in commonly used lateral ligament complex reconstructive procedures L. Muntaner-Gimbernat, L. Pico-Fuster, C. Reynes-Sancho, M. Camara-Baeza, A. Duran-Morell; Palma de Mallorca/ES

Learning Objectives: The objective of this pictorial essay is to familiarize the radiologist with the MRI findings of ankle lateral ligament complex reconstructive procedures which include modified Evans reconstruction, modified Watson Jones reconstruction, and Bromston-Gould procedure.Background: Surgery is necessary for acute grade III sprains or chronic instability. Rationale and discrepancies between procedures with day to day practice and the radiological literature are presented.Imaging Findings: Twenty patients were examined clinically and with MR imag-ing, both after reconstruction procedure with careful correlation of clinical and MRI findings.Conclusion: Appropriate knowledge of the range of MRI features and the radio-logical aspects of the lateral ligament complex reconstructive procedures assure an accurate follow-up diagnosis.

C-634 Characterization of gout artrhopathy by ultrasound C.I. Whittle, M. Cortes, G. Schiappacasse, J. Niedmann, J. MacKinnon; Santiago/CL (carolinaw@mi.cl)

Learning Objectives: To present and to analyze the sonographic features that support the diagnosis of gout.Background: Gout arthropathy is a metabolic disorder characterized by hyperuri-cemia with deposit of monosodium urate crystals within joints, affecting adult men mostly. Radiological signs appear 5-10 years after the first episode. High resolution ultrasound (US) has an important role in musculo-skeletal evaluation, with high quality images of the soft tissues.Procedure Details: We present six patients, three hand-wrist and two foot with clinical diagnosis of tendinopathy or inflammatory process and one shoulder suspi-cious of gout. US showed tiny irregularity of bone surface in hand and foot. In all cases tophus correspond to soft tissue rounded tumor with irregular echogenic material suggesting crystal or calcifications, surrounded by a hypoechogenic ring. Synovial enlargement and intra-articular effusion were also present. In shoulder, subacromioal-subdeltoid bursitis with amorphous echogenic debris was observed. A fine needle guided aspiration was performed. Analysis of synovial fluid confirmed presence of urate crystals.Conclusion: At early stages of gout soft tissues swelling and thopi are found. Later, crystals deposits produces injure of underlying bone cortex. Urate crystals in synovial fluid is diagnostic.US is an excellent tool for study soft tissues of the most frequent joints affected by gout and it can detect the presence of tophi and calcifications (patognomonic finding), synovial enlargement and fluid. Also fine needle guided aspiration can be performed.

C-635 Magnetic resonance imaging of knee cartilage disorders at 3.0 T: Spectrum of findings M. Artsybasheva, S.P. Morozov, S.K. Ternovoy; Moscow/RU (msp@cch.pmc.ru)

Learning Objectives: To demonstrate the application of 3.0 T MRI for the assess-ment of cartilage pathologic changes in patents with and without knee injuries. To illustrate major findings and diagnostic pitfalls of the technique.Background: Contemporary clinical work-up of patients with knee pain routinely includes MRI of the diseased joint. Hence, musculoskeletal radiologist faces a wide variety of pathologic changes, frequently involving cartilage of femur, tibia and patella. Recent introduction of clinical 3.0 T MR-systems has provided radi-ologists with a powerful tool for early diagnosis of minimal cartilage injuries and chondromalacia.Procedure Details: The study sample included 20 patients with knee pain, divided into 3 groups: A - patients with recent trauma history (40%), B - young patients without recent trauma history (20%), and C - older patients without recent trauma history (40%). Cartilage assessment included examination of patella, medial and lateral condyles of femur and tibia (5 zones). Per-zone analysis demonstrated cartilage changes of the first degree (high signal on T2-weighted images) in 17% of cases, second degree (cartilage thinning of less than 50%) in 21% of cases, third degree (cartilage thinning of more than 50%) in 19% of cases, and fourth degree (full thickness cartilage defect) in 43% of cases. Concomitant knee changes were observed in 80% of patients.

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Conclusion: MRI became “one-stop-shop” method of knee assessment before arthroscopic surgical treatment. 3.0 T MR-systems allow early diagnosis of knee cartilage changes. Recognition of MRI features of normal and diseased cartilage is the basis for accurate preoperative morphological diagnosis.

C-636 Imaging of prosthetic joint infection with focus on scintigraphy R. Dwarkanath, R. Jayan, C.N. Ramesh, M.L. Smith, S. Vinjamuri; Liverpool/UK

Learning Objectives: To understand the role of different imaging modalities includ-ing scintigraphy in diagnosis of prosthetic joint infection.Background: The complications of orthopaedic joint prostheses include infection and aseptic loosening and accurate diagnosis is crucial. Clinical signs, inflamma-tory markers and joint aspiration are not often conclusive. In this setting, imaging plays an important role in establishing the diagnosis.Imaging Findings: Plain radiography has low sensitivity and specificity for diag-nosis. Interpretation of Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are affected by the artefacts produced by the prostheses themselves. Functional imaging using radionuclides are very useful in this setting. Bone scan-ning is useful as an initial screening test as it has high negative predictive value and sensitivity. An abnormal scan needs further evaluation as it lacks specificity. A number of imaging options are available at this point to diagnose infection. These include Tc-99m or In-111 labelled white cell imaging, Gallium -67, and more recently Tc-99m Sulesomab - a murine monoclonal antibody fragment targeting white cells. The best imaging agent depends upon patient characteristics, the joint affected and the duration after surgery. The advantages and disadvantages of the above agents are discussed with illustrative examples.Conclusion: Imaging plays an important role in diagnosis of prosthetic infection. Scintigraphy is very useful in this setting as it offers many advantages over other imaging modalities. The choice of the right radionuclide for imaging improves the accuracy of diagnosis.

C-637 Radiologist role in femoroacetabular impingement M. Martinez Montalban, A. Garcia de Vicente, J. Acosta Batlle, I. Diez Perez de las Vacas, A. Ramirez-Escobar, L. Garcia del Salto; Madrid/ES (martamartinezm@hotmail.com)

Learning Objectives: To describe and illustrate the spectrum of appearance of femoroacetabular impingement (FAI) using plain conventional radiography, MR imaging, MR arthrography and multidetector CT (MDCT) examinations. To describe the imaging techniques and to evaluate their efficacy in the detection and charac-terization of FAI. To describe the pitfalls and artefacts.Background: Femoroacetabular impingement is a recently recognized cause of hip pain in all age groups and a proposed mechanism in the development of early osteoarthritis. FAI refers to abnormal contact between the anterior and anterosu-perior femoral head-neck junction against the acetabular rim adjacent to it. Those repetitive contacts may instigate chondral lesions and labral tears leading to early degenerative disease. Two types of FAI can be distinguished. Impingement can be attributable to femoral causes (cam impingement) or acetabular causes (pincer impingement). Cam impingement is most common in young athletic males and pincer impingement in middle-aged women. MR imaging, and in particular MR artrography, are the modalities of choice to evaluate the acetabular labrum and articular cartilage.Imaging Findings: We review the anatomy of the femoroacetabular joint and the mechanisms of impingement in this clinical entity.We describe the MR, MR arthrography and MDCT protocols used in our hospital in suspected FAI. The radiological findings in the two types of FAI using conventional ra-diography, MR imaging, MR arthrography and MDCT are described and illustrated.Conclusion: The knowledge of the spectrum of radiological findings in femoroacetabu-lar impingement may allow an early recognition and appropriate treatment, delaying the progression toward degenerative hip disease, particularly in younger patients.

C-638 The frequency of middle glenohumeral ligament pathology and coexistent middle and inferior glenohumeral ligament involvement in traumatic and non-traumatic shoulder joint instability: MR arthrography findings M. Natsika1, I. Katsimilis1, E. Panourgias1, H. Patsopoulos1, A.H. Karantanas2; 1Athens/GR, 2Iraklion/GR (katsimilisioannis@hotmail.com)

Learning Objectives: To present the contribution of MR arthrography (MRa) in the assessment of middle glenohumeral and coexistent middle and inferior gleno-humeral ligament (MGHL and IGHL) involvement in patients with acute traumatic and reccurent dislocation of the shoulder joint.

Background: Although according to the current theory and literature, IGHL func-tions as the major stabilizing ligament among the glenohumeral ligaments, in our study we stretch on the abnormalities of the MGHL in cases of shoulder instability. In a 16-month period, 27 patients were referred with a history of acute traumatic (7) and recurrent (20) shoulder dislocation (3 posterior, 24 anterior). MRa was performed and 21 of them were evaluated arthroscopically.Imaging Findings: In 11 out of 27 patients (2 with acute and 9 with recurrent dislocation), MRa disclosed MGHL injury in the form of tearing, stripping or split-ting. In four patients (one with acute and three with recurrent instability), lesions of both MGHL and IGHL were observed. Associated findings were: 12 BANKART, 10 Hill-Sachs, 6 ALPSA, 3 HAGL,1 AIGHL, 1 RHAGL, 7 SLAP, 3 IGHL sprain lesions. Arthroscopy confirmed 10 MGHL injuries. One patient was false positive. All the find-ings of coexistent MGHL and IGHL pathology were confirmed arthroscopically.Conclusion: MGHL was abnormal in 40% of our patients and combined MGHL and IGHL lesions were found in 15%. These results suggest that MGHL along with IGHL might be important in the maintenance of glenohumeral joint congruity. MRa is an efficient method for their assessment before treatment.

C-639 Direct MR arthrography using the standard arthroscopic portals F. Idoate1, P. Golano2, T. Fernandez-Villa1, A. Marques1, J. Achalandabaso3, J. Bruguera1; 1Pamplona/ES, 2Barcelona/ES, 3San Sebastian/ES (fidoate@imqnavarra.com)

Learning Objectives: To illustrate the technique of direct MR artrhography usng the standard arthroscopic portals without imaging guide.Background: Direct MR arthrography is the gold standard imaging technique for joint pathology. The normal technique involves approach with fluoroscopic guid-ance to place the needle intra-articularly, so it involves fluoroscopic irradiation. MR and sonographic guidance and palpation without imaging guidance have been described. In this exhibit we will show palpation-directed intra-articular injection technique to perform MR arthrography without imaging-guided assistance at the shoulder, elbow, wrist, knee and ankle, using the standard arthroscopic portals used by orthopaedic surgeons.Procedure Details: The material consisted of 120 shoulder, 50 ankle, 50 wrist, 35 knee, and 16 elbow MR athrograms done in a period of 4 years, using palpa-tion guide. A total of 32 patients had para-articular deposition of contrast following removal of the needle. Contrast agent extravasation did not adversely affect the performance or interpretation of the examination. The procedure was well tolerated by all patients with no major complications. The whole procedure was completed within 40 min, while puncture of the articulation and instillation of the contrast agent required no more than 10 min. Identification of standarized arthroscopic portal (with low risk of neurovascular lesions) routes at the shoulder (posterior portal), elbow (direct lateral portal), wrist (3-4 portal), knee (superolateral portal) and ankle (anteromedial portal) will be shown. The position and technique of puncture at each location will be exhibed.Conclusion: Palpation-guided approach using arthroscopic portals is a safe, easy to learn, and effective option to perform MR artrography.

C-640 Cystic lesions around the knee: MR imaging features M. Dias-Marra1, M. Chung1, M. Daoud-Crema1, M.L. Diaz1, F.W. Roemer1, S. Zaim2, A. Guermazi1; 1Boston, MA/US, 2San Francisco, CA/US (ali.guermazi@bmc.org)

Learning Objectives: To illustrate the MRI appearance of various cystic lesions. To illustrate with color drawings their anatomical relationship with the normal structures of the knee. To explain the clinical features and significance of these lesions. To describe the lesions that may mimic cysts around the knee including normal anatomical recesses.Background: Cystic lesions around the knee comprise a diverse group of entities and are frequently encountered during routine MRI of the knee. These lesions range from benign cysts to complications of underlying diseases such as infection, arthritis and malignancy. A correct MRI diagnosis is necessary to avoid unwarranted arthros-copy and to guide specific therapy. We reviewed 1,600 MRI of the knee performed at Boston University Medial Center between January 2005 and June 2007.Imaging Findings: MRI findings included meniscal and popliteal (Baker’s) cysts, intraarticular and extraarticular ganglia, intraosseous cysts at the insertion of the cruciate ligaments and meniscotibial attachments, proximal tibiofibular joint cysts, degenerative cystic lesions (subchondral cyst), cystic lesions arising from the bursae (pes anserine, prepatellar, superficial and deep infrapatellar, iliotibial, tibial collateral ligament and suprapatellar) and lesions that may mimic cysts around the knee including normal anatomical recesses.

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Conclusion: Benign cystic lesions around the knee are frequently encountered during routine MRI of the knee. A correct MRI diagnosis is necessary to avoid unwarranted arthroscopy and to guide specific therapy.

C-642 Comparison of 99mTc-nanocis labelled leukocyte scintigraphy and ultrasound in diagnosis of delitescence rheumatoid arthritis of the knee joint V.D. Zavadovskaya, M.A. Zorkaltsev, O.Y. Kilina, N.L. Klimentenko; Tomsk/RU (zkw@mail.ru)

Purpose: To evaluate efficacy of 99m Tc-nanocis labelled leukocyte scintigraphy and ultrasound in the diagnosis of delitescence rheumatoid arthritis of the knee joint.Methods and Materials: 42 patients (84 knee joints) with low disease activity were assessed by 99m Tc-nanocis labelled leukocyte scintigraphy (Searle Scintiscan, 370 MBk) and ultrasound (Siemens G40). The results of primary investigation were compared with secondary investigations after antirheumatic treatment.Results: Local accumulation of 99mTc-nanocis labelled leukocyte was revealed in 43 knee joints, among them were 42 TP and 1 FP. In 41 joints, accumulation was absent (37 TN, 4 FN). Sensitivity, specificity and exactness of the scintigraphy were 91, 97 and 94%, respectively. Ultrasound revealed fluid in 16 knee joints and com-bination of fluid and sinovial proliferation in 8 knee joints. As a result, 22 TP, 2 FP, 36 TN and 24 FN results were revealed. Sensitivity, specificity and exactness of the ultrasound were 48, 95 and 69%, respectively. High correlation between the results of scintigraphy and clinical-laboratory findings revealed advantage of 99mTc-nanocis labelled leukocyte scintigraphy in the indication of inflammation activity.Conclusion: In comparison with ultrasound 99mTc-nanocis labelled leukocyte scintig-raphy is more effective for the diagnosis of presence and activity of inflammation of the knee joint in patients with rheumatoid arthritis in comparison with ultrasound.

C-643 Haemophiliac arthropathy: MR imaging features in asymptomatic patients O. Papakonstantinou, H. Pergantou, A. Papadopoulos, D. Loggitsi, A. Balanika, N. Economopoulos, S. Aronis, N. Kelekis, A. Gouliamos; Athens/GR (olypapak@hotmail.com)

Purpose: To investigate the pathologic changes in 84 joints in asymptomatic haemophiliac patients by means of MR imaging and correlate the MRI and clini-cal scores.Methods and Materials: MR imaging studies of 84 joints (36 ankles, 27 knees, 19 elbows) in 21 boys with hemophilia (mean age 11.7 3.1 yrs) were perspectively performed on two 1.5 T Magnets (Philips/Intera or Magnetom/Vision/ Siemens), using T1, T2, 3D T2* FS sagittal and PD FS coronal images. All patients were asymptomatic at the time of MR imaging. MR studies were evaluated according to Denver score that comprised evaluation of joint fluid, synovial thickening/hemosid-erin deposition, cartilage loss and subchondral cysts. All joints were also evaluated clinically, using the world federation of hemophilia score, whereas plain radiographs were additionally performed in all patients within the same day of MR imaging.Results: Synovial hyperplasia with deposition of hemosiderin was the most common finding (in 67/84 joints, 79%), followed by erosions and subchondral cysts (50/84, 59%) and cartilage loss (43/84 joints, 51%), whereas intraosseous pseudotumors were seen in 3 patients. Twenty-two joints were normal on radiography; MRI was positive in eight of them and negative in eleven, respectively. MRI score correlated with clinical score (r=0.42, p 0.001).Conclusion: MR imaging can reveal joint abnormalities in asymptomatic haemo-philiac patients that may go undetected on clinical examination and radiographs, necessitating initiation or more intensified prophylactic treatment.

C-644 Pharmacokinetic analysis of the patellar cartilage in DCE-MRI: Comparison between 1.5 and 3 Tesla L. Marti-Bonmati, R. Sanz; Valencia/ES (luis.marti@uv.es)

Purpose: To analyze the pharmacokinetic parameters of the patellar cartilage in dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in normal, chondromalacia and osteoarthritis subjects and to compare 1.5 T with 3 T analysis results.Methods and Materials: 29 subjects (6 normal, 12 with chondromalacia, 11 with osteoarthritis) underwent 1.5 T DCE-MRI of the patellar cartilage. Four of the normal subjects also underwent a 3 T DCE-MRI too. The MR sequence for 1.5 T and 3 T was a gradient echo (TR 4 ms, TE 1.7 ms, flip angle 10º, voxel size 0.78x0.78x6 mm, time resolution 3s). Contrast agent was injected intravenously as a bolus (0.2 ml/kg at 4 ml/s, 40 ml saline flush). Four parameters were studied: permeability (Ktrans,

ml/min/100 ml), extraction ratio (kep, ml/min/100 ml), extravascular extracellular space fraction (ve, %) and vascular space fraction (vp, %).Results: For the normal group, Ktrans was 3.5 3.2, kep 358.1 167.5, ve 4.6 5.0 and vp 0.2 0.2. For the chondromalacia group, Ktrans was 14.1 9.1, kep 362.8 124.1, ve 6.1 4.7 and vp 1.2 1.9. For the osteoarthritis group, Ktrans was 17.0 11.9, kep 350.2 123.9, ve 12.0 9.2 and vp 1.8 2.5. Statistical analysis show significant differences between groups for Ktrans (p=0.03) but no significant differences for ve (p=0.06), kep (p=0.97) and vp (p=0.28). Although no significant differences were observed between 1.5 T and 3 T, a tendency towards higher values was observed with the 1.5 T analysis.Conclusion: Pharmacokinetic permeability parameters of the patellar cartilage can successfully distinguish between different cartilage states (normal, early and advanced degeneration). A significant increase in capillary permeability was found as the degeneration progresses.

C-645 Deterioration of articular cartilage associate with bone bruise after acute knee injury: Assessment with T2 mapping T. Okubo, A. Watanabe, H. Yamada, K. Sato, Y. Wada, T. Yamashita, K. Matsuki; Ichihara Chiba/JP (tokubo-tky@umin.ac.jp)

Purpose: The aim of this study is to evaluate the relationship between bone bruise and deterioration of cartilage in patients with acute knee injury by use of quantitative magnetic resonance (MR) imaging technique, T2 mapping.Methods and Materials: 25 knees of 25 patients (7 women and 18 men, mean age 29.3 years) with acute anterior cruciate ligament injury were studied with a MR imaging system at 1.5 Tesla (Signa, GE Medical Systems, Milwaukee, WI). Fat-suppressed T2 weighted imaging and T2 mapping in the coronal plane were performed, and T2 value of the cartilage at medial and lateral condyle was mea-sured. The relationship between T2 value of the cartilage and the presence or absence of bone bruise was investigated using unpaired t-test.Results: Of the 25 patients, 14 had a bone bruise at lateral femoral condyle. In the patients without bone bruise, there was no significant difference in the mean T2 value between medial femoral condyle and lateral femoral condyle, 31.5 ms and 33.1 ms, respectively. The mean T2 value of cartilage with bone bruise was significantly higher than that without bone bruise, 37.3 and 32.7 ms, respectively.Conclusion: It is known that T2 value increases with the loss of collagen anisotropy and increase in water content observed in the early stage of cartilage deterioration. Thus the presence of bone bruise at the femoral condyle after acute knee injury might indicate the presence of cartilage deterioration at that site.

C-646 MR imaging of medial meniscal root tears: Tear configuration, diagnostic accuracy, and the associated abnormalites J.-C. Shim, J. Kim, Y.-H. Kim, G. Lee, H. Kim, J. Suh; Seoul/KR (promind@lycos.co.kr)

Purpose: To evaluate the tear configurations, diagnostic accuracy, and the associ-ated abnormalities on MR imaging in medial meniscal root tears.Methods and Materials: We retrospectively reviewed MRI reports, performed by one experienced musculoskeletal radiologist, and images of 146 knees of 144 patients who underwent preoperative MR imaging of the knee, and had arthroscopy of the knee, from January 2005 to June 2007. We evaluated the configuration of the meniscal root tear and the other associated knee abnormalities that were con-firmed during arthroscopy. We reviewed all MRI reports to estimate the diagnostic accuracy of MRI.Results: At arthroscopy, there were 48 medial meniscal posterior horn root tears including 38 full-thickness radial, 7 partial-thickness radial, and 3 complex tears. Overall sensitivity, specificity, and accuracy for the detection of medial meniscal root tear regardless of tear configuration were 94% (45/48), 98% (96/98), and 97% (141/146), respectively. In classification of tear configuration, sensitivity, specificity, and accuracy were 82% (31/38), 70% (7/10), and 79% (38/49) for full-thickness radial tears, and 43% (3/7), 80% (33/41), and 75% (36/48) for partial-thickness radial tears. The incidence of degenerative joint disease was 85% (41/48). In as-sociation with degenerative joint disease, the incidence of cartilage defects of the medial femoral condyle and medial meniscal extrusion ( 3 mm) were 80% (33/41), and 56% (23/41).Conclusion: MR imaging is accurate for the detection of medial meniscal root tears. Medial meniscal root tears were highly associated with degenerative joint disease, cartilage defects of the medial femoral condyle, and medial meniscal extrusion.

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C-647 In vitro human cartilage compression study at 3 Tesla using unique compression device V. Juras, Z. Majdisova, M. Bittsansky, S. Trattnig; Vienna/AT (vladimir.juras@meduniwien.ac.at)

Purpose: The purpose of this study was to use special designed compression device adapted to a micro-gradient system to study the effects of mechanical compression of human cartilage explants on T1, T2 and apparent diffusion coef-ficient (ADC) by application of a highly accurate and localized compression of articular cartilage.Methods and Materials: Cartilage samples were prepared from joints of 10 patients who underwent a total knee joint replacement. The samples were 10x10x3 mm in dimension. The study was performed on a Bruker 3 T Medspec whole-body scanner (Bruker, Ettlingen, Germany) using BGA-12 micro-gradients with a special designed compression device. Cartilage samples were compressed in 15% of its thickness. T1, T2 and ADC maps were calculated for pre- and post-compression state. Values were evaluated in the selected ROI in the area of compression; moreover, T2 was evaluated in deep and superficial zone separately.Results: T1, T2 and ADC are related to the pressure loaded onto a cartilage tissue. In the case of cartilage thickness change of 15%, ADC decreased for 10.15%, T1 increased for 22.04% and T2 decreased for 13.97% and 6.23% in the superficial zone and deep zone, respectively.Conclusion: Equipment for cartilage compression evaluation is feasible for study-ing the influence of pressure on cartilage tissue with high accuracy of localization and loading control. The pilot data evaluated are in good agreement with already published results. The advantage of this approach is that data obtained from a micro-imaging system provide high-resolution images and precise localization of every compared pixel.

C-648 Study of the anterolateral recess of the ankle with CT arthrography and MR arthrography E. Pessis1, A. Feydy2, R. Campagna2, J. Elis1, J.-L. Drapé2, H. Guerini2, F. Thévenin2, A. Chevrot2; 1Saint Denis/FR, 2Paris/FR (antoine.feydy@cch.aphp.fr)

Purpose: The purpose of this exhibit is to: 1. review CT arthrography and MR arthrography appearance of the anterolateral recess of the ankle with surgical correlation and 2. learn optimal methods to detect anterolateral ankle impingement and ligamentous injury.Methods and Materials: Forty-three patients with chronic ankle pain prospectively underwent gadolinium-enhanced MR arthrography and CT arthrography of the tibio-talar joint. All patients underwent clinical examination and were included if anterolateral impingement (n=22) or a control condition (n=21) was diagnosed at arthroscopy. MR imaging included transverse and coronal 3D fiesta sequences, sagittal T2-weighted fat-suppressed, axial T1-weighted fat-suppressed imaging sequences. MR and CT and arthrographic findings were correlated with subsequent arthroscopic appearances.Results: For the assessment of anterolateral impingement of the ankle, MR arthrography had an accuracy of 93%, sensitivity of 86%, specificity of 100%, posi-tive predictive value of 100%, and negative predictive value of 88%. Thickening of the anterior talofibular ligament associated with focal or diffuse thickening of the anterolateral capsular tissues were identified at MR arthrography in 19 cases, and in none of the control cases.Conclusion: The major teaching points of this exhibit are: 1. Anterolateral impinge-ment of the ankle and anterior talofibular ligament injury can be assessed with CT arthrography and MR arthrography. 2. The finding of a soft tissue scarring associ-ated with a thickened anterior talofibular ligament is suggestive of the diagnosis of anterolateral impingement of the ankle.

C-649 Bovine collagen meniscus implant: Long term follow-up with MRI M.G. Angeretti, C. Ratti, P. Bulgheroni, A. Leonardi, E. Bertolotti, E.A. Genovese, C. Fugazzola; Varese/IT (eugegeno@tin.it)

Purpose: To evaluate the role of MRI in the long term follow-up (5 to 6 years) of patients that underwent bovine collagen meniscus implant (CMI) by identifying MR imaging patterns able to describe the implant evolution.Methods and Materials: 28 patients (20 males, 8 females), mean age 44.2 years (range 28-58), who underwent medial meniscus implant insertion were subject to long term follow-up by MR Arthrography with integrated DP/T2 FATSAT sequences that allowed morphologic assessment of the joint. Factors assessed in order to evaluate the implant evolution were size and implant signal intensity, as well as the status of the chondral surface and of the subchondral bone spongiosa.

Results: Long term follow-up MR showed reabsorbtion of the collagen implant in 3 of 28 cases. In 11 of 28 patients, the thickness of the implant was stable compared to the 2-year follow-up exam, with no significant reduction in size and displaying a homogenous hypointense signal. In 14 of 28 cases, a reduction in implant size was identified. Regarding the presence of associated degenerative osteochondral phenomena, in 15 of 28 cases there was no progression of the existing, previously described findings. MR arthrography was able to reveal 5 new cases of chondral pathology and to correctly grade all lesions.Conclusion: MRI allows accurate long term monitoring of morphologic and structural variations of the CMI, demonstrating in most cases long term “stability” of the implant.

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C-650 Ulnar nerve entrapment: Dynamic ultrasound maneuvers to improve diagnosis S. Lucarini1, C. Romagnoli2, R. Chhem2; 1Firenze/IT, 2London, ON/CA (cesare.romagnoli@lhsc.on.ca)

Learning Objectives: To understand and learn a dynamic approach to ulnar nerve entrapment using ultrasound imaging.Background: Ulnar nerve entrapment is the second most common neuropathy in the upper extremity. Its anatomical positioning in the cubital tunnel makes it subject to entrapment from several causes, and it is easy to miss the diagnosis during routine, static ultrasound examination of the elbow. This exhibit describes the use of dynamic maneuvers during the ultrasound study, which form a valuable tool for diagnosing this condition.Procedure Details: The ultrasound examination starts with the patient’s arm lying on a flat surface with the palm facing upwards. The probe is positioned on the medial aspect of the elbow so that the ulnar nerve, which runs superficially, is easily visual-ized. By varying the position of the arm, and by specific movements of the patient’s hand, the nerve can be visualized as it slides within the cubital tunnel. This technique allows easy identification of the cause of rubbing and/or compression.Conclusion: Dynamic ultrasound maneuvers improve the diagnostic accuracy in ulnar nerve entrapment neuropathies and are often the only method to make the correct diagnosis.

C-651 Knee fat pads: What do we know about them? L. Melao1, T. Hughes2, L. Chen2, C. Canella2, D. Resnick2; 1Porto/PT, 2San Diego, CA/US (lina_melao@hotmail.com)

Learning Objectives: Review the clinical, imaging and pathologic findings and differential diagnosis of the major abnormalities of intracapsular and periarticular fat pads in the knee.Background: Several fat pads are located in or adjacent to the capsule of the knee joint. Some of them, particularly infrapatellar fat pad of Hoffa, and suprapa-tellar and prefemoral fat pads, deserve emphasis because of their involvement in several pathologic processes that may lead to clinical manifestations. With flexion and extension of the knee, the shapes and morphology of these fat pads change, depending on the various positions of the patella and femur. This anatomical feature supports an important relationship between alterations in patellofemoral biomechanics and abnormalities of these anterior fat pads (“Fat Pad Impingement Syndrome”). In addition, posttraumatic or postsurgical change in the infrapatellar fat pad can alter its morphology and interfere with normal excursion of the extensor mechanism of the knee.Imaging Findings: MR imaging findings of the abnormalities of these fat pads are discussed, including the differential diagnosis based its location and imaging appearance.Conclusion: We would like to illustrate major anatomical abnormalities of intracap-sular and periarticular fat pads of the knee, emphasizing its imaging characteristics and clinical significance.

C-652 Necrotizing fasciitis: Is emergent MRI useful to avoid a fatal outcome? M. Rodríguez Alvarez, C. Saborido, J. Leon, P. Rodríguez, J. Mañas; Vigo/ES (marta.rodriguez.alvarez@sergas.es)

Learning Objectives: Necrotizing fasciitis (NF) is a rapidly progressive infection of the soft-tissue fascia with a high mortality rate. Delay in diagnosis and/or treatment correlates with poor outcome. Initial clinical features are not more specific than those of any soft tissue infection. Our objective is to describe the MRI appearance of NF and to show the role that an emergent MRI can play obtaining an early diagnosis and helping in surgical planning.Background: We reviewed the MRI of patients with NF diagnosed of our hospital since 2001. T1-weighted, T2-weighted, STIR and contrast-enhanced T1-weighted and fat saturation images were performed in all cases. The MRI results were cor-related with pathological and surgical findings.Imaging Findings: In NF cases, MRI demonstrated in the fascial tissue: inflam-mation by mean of fluid collections or signal with long relaxation time and contrast enhancement after gadolinium administration; and necrosis as non-enhancing areas after contrast administration and presence of signal void foci due to gas.

Furthermore, some cases showed myonecrosis as non enhancing areas, fluid collections with mild peripheral enhancement or signal void foci due to gas in muscle. One case showed only inflammation and gas affecting subcutaneous fat and superficial fascia (necrotizing cellulitis).Conclusion: MRI allows depicting extention and degree of inflammation, facilitat-ing operative planning. Additionally, can show the presence of gas and adding gadolinium, it demonstrates necrosis areas included in fascia or muscle, useful information in surgical decision making. Treatment should not be delayed by imaging performance, and so NF is an emergent MRI indication.

C-653 Usual and unusual imaging findings of extracranial schwannomas O. Tokuda, Y. Harada, N. Matsunaga; Ube/JP (chinupapa@goo.jp)

Learning Objectives: To assess the usual and unusual imaging findings of ex-tracranial schwannomas.Background: Schwannoma is one of the most common soft-tissue tumors arising from the Schwann cells of the nerve sheath. Spinal schwannoma is common intra-spinal tumor, representing 25-30% of all intraspinal masses. Typical imaging findings of spinal schwannoma include target sign, intratumoral cysts and dumbbel-shaped appearance. Extensive vertebral destruction, growing into vertebral artery foramen and intramedullary schwannoma are rare. In addition, schwannoma infrequently occurs in the mediastinum, retroperitoneum, and extremities.Imaging Findings: 50 patients proven histologically were included in this exhibit. 31 patients had usual and 19 patients had unusual imaging findings. In spinal le-sion, unusual imaging findings included multiple schwannomas, presentation as a cystic mass, intraosseous schwannoma, schwannoma growing into the vertebral artery foramen, and intramedullary schwannoma. Intraosseous schwannoma demonstrated expansive destruction of vertebral body with cortical thinning on CT. Schwannoma growing into the vertebral artery foramen demonstrated dis-placement of the vertebral artery. In extraspinal lesions, unusual imaging findings included schwannoma of iliopsoas compartment, pelvic cavity, brachial plexus, and intercostal region. Ancient schwannoma of the thigh demonstrated hyperintense signal corresponding to the Antoni type B area on T2 weighted images, and multiple punctate enhancements in the lesion. Malignant giant schwannoma of the buttocks demonstrated peripheral enhancement around the iliac bone.Conclusion: Extracranial schwannomas are commonly encountered tumors with typical imaging findings. However, they can demonstrate unusual imaging features. To know unusual presentations of the tumors is important in offering a correct preoperative diagnosis.

C-654 Iiopsoas compartment: Normal anatomy and diverse imaging spectrum of disorders Y. Harada, O. Tokuda, N. Matsunaga; Ube/JP

Learning Objectives: To learn imaging features of normal anatomy and various disorders in the iliopsoas compartment.Background: Disorders in the iliopsoas compartment may include inflamma-tory, hemorrhagic, and neoplastic conditions. The knowledge of detailed normal anatomy and pathological process in the iliopsoas compartment can help improve the diagnostic accuracy.Procedure Details: The iliopsoas compartment is an extraperitoneal space which contains the greater psoas major, psoas minor, and iliacus muscle. Illustrations of gross and cross-sectional anatomy of the compartment are discussed. 112 patients diagnosed clinically or histologically are included in this exhibit. CT (n = 98) and MR (n = 44) imaging features were retrospectively reviewed. Disorders in the ilio-psoas compartment consisted of infection (n = 45), tumor (n = 35), hematoma (n = 25), and others (n = 5). The category of infections included spondylitis, abscess, spreading from intraperitoneal inflammation, and iliopsoas bursitis. The category of hematoma included rupture of abdominal aortic aneurysm, trauma, iatrogenic injury, and unknown etiology. The category of tumors included direct extension of retroperitoneal (colon cancer, liposarcoma, renal cell carcinoma, et al)., pelvic (extraskeletal chondrosarcoma, leiomyosarcoma, et al)., and bone tumors (giant cell tumor, osteosarcoma, and myeloma), direct invasion from adjacent lymph nodes, hematologic spread of malignancies (malignant melanoma, breast cancer, et al)., and primary tumors (schwannoma).Conclusion: There are many disorders which involve the iliopsoas compartment. The knowledge of the detailed normal anatomy and pathological process in the iliopsoas compartment can lead the radiologists to accurate diagnosis.

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C-655 The value of sonographic movie-loops for dynamic assessment of functional musculoskeletal pathologies S. Peer, G. Widmann, H. Gruber; Innsbruck/AT (siegfried.peer@i-med.ac.at)

Learning Objectives: To illustrate the potential of sonographic movie-loops for diag-nosis and documentation in a variety of functional musculoskeletal pathologies.Background: In the sonographic evaluation of orthopedic and trauma patients a variety of functional musculoskeletal pathologies is encountered. As sonography is an interactive modality, they are easily reproduced by functional sonography during a variety of provocative maneuvers. The documentation of these examina-tions traditionally consists of single images at the end-points of such a maneuver. Modern ultrasound equipment however allows for direct acquisition of real time sonographic movie loops.Imaging Findings: By means of selected movie-loops acquired in pathologies such as snapping triceps syndrome, supinator syndrome, wrist impingement, tendon rupture (finger flexors, quadriceps tendon) and other musculoskeletal syndromes, the importance of functional sonographic assessment and real time analysis for diagnosis is demonstrated.Conclusion: Real time documentation with sonographic movie-loops during provocation tests is an important add-on in the tool-box of the modern sonographer that helps in the diagnosis of functional musculoskeletal pathologies, which may otherwise go undetected.

C-656 Magnetic resonance imaging findings of leg musculature in Charcot-Marie-Tooth type 1 A disease: From the beginning to the end E. Gallardo, R. Pellón, G. Blanco, R. García-Barredo, A. García, J.A. Berciano; Santander/ES (egallardo@humv.es)

Learning Objectives: 1. Recognize the different MRI patterns of muscle involve-ment that characterized this disease. 2. Identify the initial patterns of muscle involvement in preclinical phase of the disease.Background: Charcot-Marie-Tooth (CMT) disease is a group of inheritable defects in the proteins of the peripheral nerve myelin sheath, being CMT 1 A, an autosomal dominant polyneuropathy, the most common form of the disease. CMT 1 A hallmark is a peroneal muscular atrophy syndrome of variable severity and marked and dif-fuse slowing of nerve conduction velocity. Symptoms are present during the first decade in over 60% of cases. The clinical course is quiescent especially during the first two decades. MRI helps to evaluate the extent and number of muscles involved, objective identification of the distribution of muscle degeneration and the severity of the process are important in treatment planning.Imaging Findings: We present the main clinical, electrophysiological and MRI findings of this disease structured in the following sections: foot phenotype in asymptomatic patients, leg phenotype in asymptomatic patients, foot phenotype in established disease, and leg phenotype in established disease.Conclusion: MRI is helpful in the early diagnosis of Charcot-Marie-Tooth disease since it provides sensitive and topographic information about initial and even pre-clinical muscle involvement. This information may be useful in clinical practise for different neuromuscular disorders and could be used as an additional tool in the diagnostic algorithm of these entities.

C-657 Pain syndrome of the anatomical snuffbox: Differential diagnosis by high resolution ultrasound E. Gallardo, N. Valle, J. Izquierdo, F. Peñas, R. Landeras, M.A. Fernández Echevarría; Santander/ES (egallardo@humv.es)

Learning Objectives: 1. Study of the normal anatomy and standard technique for anatomical snuffbox sonographic exploration. 2. Diagnosis by means of ultrasound of the most frequent diseases that cause pain in this location.Background: The anatomical snuff box is a triangular space on the radial and dorsal aspect of the hand, at the level of the carpal bones, which is delimited and occupied by different structures (tendons, bones, vessels and nerves). The occurrence of selective pain at the snuffbox is a daily cause of medical consultation.Imaging Findings: Review of the normal sonographic anatomy of the snuffbox components. Description of the diseases that characteristically affects this com-partment: arthropathies: rhizarthrosis, inflammatory arthritis tendon disorders: De Quervain’s tenosynovitis, tendon failure bone lesions: scaphoid occult fracture, pseudoarthrosis soft-tissue masses: ganglia, lipomas, pseudoaneurysms, arterio-venous fistulas, and neuromas.Conclusion: High resolution ultrasound provides useful information about this syndrome and improves significantly clinical diagnosis.

C-658 Radiologic-pathologic correlation of musculoskeletal neurogenic tumors M. Ruiz de Gopegui Andreu, M. Tapia Viñe, C. Martín Hervás, D. Bernabeu Taboada, F. López Barea, E. Alonso Gamarra; Madrid/ES (mgopegui@yahoo.es)

Learning Objectives: To illustrate the spectrum of cross sectional imaging findings for various types of neurogenic tumors with pathologic correlation.Background: Numerous neurogenic tumors can affect the musculoskeletal sys-tem, including traumatic neuroma, Morton neuroma, schwannoma, neurofibroma and malignant peripheral nerve sheath tumors (PNSTs). Neurogenic neoplasms represent approximately 10-12% of all benign soft tissue neoplasms and PNSTs account for 5-10% of soft tissue sarcomas. The traumatic neuroma and Morton neuroma are not true soft tissue tumors but rather represent pseudotumors le-sions of nerve.Imaging Findings: The diagnosis of neurogenic tumors can be suggested from their imaging appearances, including lesion shape and intrinsic imaging characteristics. Radiologic key features of CT, sonography and MR imaging include the relationship to the nerve, fusiform shape, “split fat” sign, fascicular sign, target sign and associ-ated muscle atrophy. Although differentiation of schwannoma from neurofibroma and of benign from malignant PNST is problematic, recognition of the radiologic appearances of neurogenic tumors often helps to suggest diagnosis and improves clinical management of patients. Imaging features that are more suggestive of PNST include large size (greater than 5 cm), recent rapid growth, heterogeneity, significant vascularity, infiltrative margins and increased gadolinium uptake.Conclusion: 1) CT, sonography and MR imaging help in characterization of musculoeskeletal neurogenic tumors. 2) Radiologic imaging detects signs that suggest aggressiveness. 3) Cross sectional imaging depicts location, extension and involvement of surrounding tissues, which are fundamental for optimal patient management.

C-659 Occult groin hernias: Anatomy and techniques S.S. Iyengar, A. Abdellaoui, M. Vouros, A. Raza, A. Davies, A. Gafoor, P. Suresh, P. Hughes; Plymouth/UK (srikanthiye@gmail.com)

Learning Objectives: 1) To illustrate the anatomy of inguinal and femoral regions with ultrasonographic correlation. 2) To demonstrate a systematic sonographic technique for evaluation of inguinal and femoral hernias using MPEG clips.Background: Groin pain from clinically occult hernias represents a challenging differential diagnosis. Ultrasound represents a non-invasive method for investigating patients with a high clinical index of suspicion of groin hernias or a normal pelvic MRI. Ultrasound examination accurately demonstrates the anatomy of the groin and provides a dynamic visualisation of herniation, which cannot be obtained with MRI.Procedure Details: We illustrate our technique of evaluating the groin and demon-strate with video clips (MPEG) the assessment and features of direct/indirect ingui-nal and femoral hernias. We use a Toshiba Aplio™ Ultrasound machine (Toshiba Inc, Japan) with a 12 MHz linear array probe. The examinations are performed by one of the three musculo-skeletal specialists.Conclusion: A pictorial review of the anatomy, technique and appearances of groin hernias is presented with dynamic and static images.

C-660 Imaging of tropical pyomyositis W.C.G. Peh1, H.E.L. Teo1, N. Pattamapaspong2; 1Singapore/SG, 2Chiang Mai/TH (wilfred.peh@gmail.com)

Learning Objectives: To know the clinical features and stages of tropical pyo-myositis. To recognize the imaging appearances, particularly MR imaging, of this disease and its role in staging and patient management.Background: Tropical pyomyositis has a high incidence in the tropics, but it is increasingly seen in temperate countries due to its association with patients in-fected with the human immunodeficiency virus and other predisposing factors. The commonest causative organisms are Staphylococcus aureus and Streptococcus. There are three clinical phases of infection. If untreated, the disease progresses to the third stage where there is generalized toxicity with resultant osteomyelitis, septic arthritis or pyomyositis.Imaging Findings: Radiographs may show underlying osteomyelitis, fat plane obliteration, soft tissue swelling and gas in the soft tissues. Scintigraphy detects multifocal or occult infection. Two sonographic appearances of pyomyositis are related to the first two stages of the disease. CT shows muscle changes in stages 1 and 2, as well as surrounding subcutaneous inflammation, concomitant deep

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vein thrombosis and osteomyelitis. In stage 1 of infection, MR imaging shows an enlarged edematous muscle, with diffuse altered T1- and T2- signal intensity. In stage 2, areas of T2-hyperintense and T1-hypointense signal, with rim enhance-ment, are seen. Differentiation between stages 1 and 2 of the disease helps identify patients who can be treated with antibiotics alone from those who require drainage. MR imaging also shows infective involvement of the surrounding bone.Conclusion: Recognizing the imaging features of tropical pyomyositis and cor-relation with clinical phases help direct patient management.

C-661 Superficial soft-tissue masses of the extremities: Differential considerations on ultrasound N. Kim, S. Hong, J.-Y. Choi, J. Lee, J.-A. Choi, H. Kang; Seoul/KR

Learning Objectives: To illustrate various sonographic findings that help to distinguish superficial soft-tissue masses of the extremities. To describe the char-acteristic features of benign and malignant soft-tissue lesions in establishing the differential diagnosis.Background: Superficial soft-tissue masses are among the most common indi-cations for ultrasound of the extremities. In the cases of some masses, such as superficial lipomas, the imaging characteristics usually enable a definite diagnosis. However, it is said that the imaging features of many other superficial soft-tissue masses may be disappointingly nonspecific.Imaging Findings: A total of 117 patients who underwent sonographic evaluation of a superficial soft-tissue mass followed by percutaneous needle biopsy or excision were retrospectively evaluated. The majority of superficial soft-tissue masses con-sisted of 52 (44%) lipomas, 17 (15%) epidermal cysts, 8 (7%) neurogenic tumors, and 6 (5%) hemangiomas. Other miscellaneous soft-tissue masses were followed and included angiolipoma, angioleiomyoma, Kimura’s disease, endometriosis, ju-vernile xanthogranuloma, sparganosis, palisaded myofibroblastoma of lymph node, dermatofibrosarcoma protuberans, verrucous carcinoma, malignant melanoma, and metastasis. Common superficial soft-tissue masses revealed high diagnostic accuracies. Many of the maliganant lesions showed peripheral hyperechoic halo, skin retraction, indistinct margin, non-parallel shape, and peripheral vascularity.Conclusion: Sonography demonstrates high accuracy in the diagnosis of com-mon superficial soft-tissue masses and considerably specific features in malignant lesions.

C-662 Classification and imaging spectrum of soft tissue vascular malformations: Guide to correct management R. Gupta, M. Gupta, A. Seith; Delhi/IN (rushme89@rediffmail.com)

Learning Objectives: To describe proper classification system of soft tissue vascular malformations and to illustrate imaging spectrum on Doppler ultrasonog-raphy, MRI, MRA and DSA, which are the critical imaging modalities in establishing diagnosis, evaluating the extent and planning appropriate treatment.Background: Vascular malformations cause significant morbidity in all age groups. Radiologists are involved in both imaging and treatment. The nomenclature used is often wrong and confusing. A proper classification system is described, along with illustration of important imaging features, which will help in deciding further management. For instance, hemangiomas involute spontaneously with age and hence require no treatment, whereas high-flow malformation requires early in-tervention.Imaging Findings: Vascular malformations are classified into vascular tumours (hemangiomas) and true vascular malformations. Hemangiomas are further clas-sified into proliferative and involutive stages. True vascular malformations are clas-sified into slow flow, which includes venous, capillary, lymphatic and venolymphatic malformations, and high flow, which includes arteriovenous malformation and arteriovenous fistulas. Knowledge of imaging features of these lesions on USG, Doppler, MRI, MRA and DSA will help in proper classification and thus appropriate treatment. A complete spectrum of all these types, along with imaging of associated syndromes like Klippel trenauny syndrome is illustrated.Conclusion: Vascular malformations pose a difficult challenge, and the first rule for appropriate mamagement is to refer to a proper classification scheme. USG and Doppler are the primary modalities for diagnosis and classification. MRI and MRA are helpful in few difficult cases and for the depiction of the true extent of lesions. DSA is mainly required prior to intervention.

C-663 Role of ultrasound in the evaluation of scapholunate ligament tears: A pictorial review L. Pesquer1, P. Pelissier2, P. Meyer1; 1Merignac/FR, 2Bordeaux/FR (lionelpesquer@gmail.com)

Learning Objectives: 1. To review the normal anatomy and the US modalities to explore the scapholunate ligament. 2. To describe the US appearances of scapholunate ligament injuries. 3. To discuss the strengths and weaknesses of US examination.Background: Scapholunate ligament tears can lead to severe wrist instability and cartilaginous lesions. An adequate technique as well as good knowledge of the anatomy are mandatory for a thorough assessment of the wrist ligaments.Imaging Findings: Scapholunate ligament is a fibrillar structure located between the scaphoid and lunate bones. Loss of fibrillation and hypoechoic disruption are the main signs of lesion. Color Doppler, the use of harmonic mode and dynamic examination are helpful to improve diagnosis.Conclusion: Ultrasound is an excellent and non-invasive modality for evaluation of scapholunate ligament tears.

C-664 Effects of strength training on metabolism of resting skeletal muscle M.-A. Weber1, W. Hildebrandt1, L. Schröder1, R. Kinscherf2, M. Krix1, P. Bachert1, S. Delorme1, M. Essig1, H.-U. Kauczor1, H. Krakowski-Roosen1; 1Heidelberg/DE, 2Mannheim/DE (m.a.weber@dkfz.de)

Purpose: To assess the effects of strength training on metabolism and microcir-culation of resting skeletal muscle.Methods and Materials: Thirty-nine subjects were trained twice a week on an isokinetic system (altogether 16 sessions lasting 50 min, intensity at least 75% of maximum isokinetic and isometric force of knee flexors and extensors). To evaluate success of training, cross-sectional area (CSA) of the quadriceps femoris muscle and its isokinetic and isometric forces were quantified. Muscular fiber size and capil-larization were measured in biopsies of the vastus lateralis muscle. The muscular energy and lipid metabolism was quantified by magnetic resonance spectroscopy and parameters of muscular microcirculation, such as local blood volume, blood flow and velocity by contrast-enhanced ultrasonography.Results: The significant (P 0.001) increase in CSA (60 16 before vs. 64 15 cm2

after training) and in absolute muscle strength (isometric, 146 44 vs. 174 50 Nm; isokinetic, 151 53 vs. 174 62 Nm) demonstrated successful training. Neither capillary density ex vivo (351 75 vs. 326 62) nor ultrasonographic parameters of resting muscle perfusion were significantly different (blood flow, 1.2 1.2 vs. 1.1 1.1 ~ml/min/100 g; blood flow velocity, 0.49 0.44 vs. 0.52 0.74 mm/s). Also, the intensities of high-energy phosphates phosphocreatine and adenosine-triphosphate were not different after training within the skeletal muscle at rest (adenosine-triphosphate/phosphocreatine, 0.29 0.06 vs. 0.28 0.04). However, the intramyocellular -CH3 lipids were elevated after training ([3.49 3.16] ×103 vs. [6.26 6.45] ×103, P=0.009).Conclusion: The training-induced increase in muscle volume and strength is not reflected by elevated microcirculation and phosphate metabolism of resting skeletal muscle, but an elevated concentration of certain intramyocellular lipids.

C-665 Liposarcoma or lipoma: Does cytogenetics change classic criteria?F. Bidault1, D. Vanel1, L.G. Shapeero2, A. Jalaguier1, A. Athanasiou3, S. Bonvalot1, P. Terrier1, F. Pedeutour1, J. Couturier1, C. Dromain1; 1Villejuif/FR, 2Bethesda, MD/US, 3Paris/FR (bidault@igr.fr)

Purpose: Differentiating benign from malignant well-differentiated fatty tumors has always been very difficult for radiologists and pathologists. Cytogenetics allows more accurate diagnoses of soft tissue tumors. Our objective was to analyze the reliability of classic imaging criteria used to differentiate lipoma from liposarcoma, compared to this new reference.Methods and Materials: 19 patients with a fatty tumor (5 benign and 14 malignant) were included. All had CT and/or MRI examination before biopsy or surgery, with histological and cytogenetic analyses.Results: The imaging diagnosis of benign or malignant lesions was accurate in 15 cases, with 4 false positives for malignancy. Erroneous criteria were deep-seated lesions and/or large sizes (3) and a mass that was not purely fatty.Conclusion: Classic imaging criteria may lead to false positives for malignancy. A homogeneous fatty tumor can be a lipoma, even if it is large and deep-seated.

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C-666 Sonographic evaluation of the rotator cuff after surgical repair of humeral diaphyseal fractures A. Hilario, P. Manjon, A. Alcala-Galiano, A. Delgado, P. Martin, R. Garcia-Bogalo; Madrid/ES (amayahilario@yahoo.es)

Purpose: One of the most controversial points related to surgical approach of hu-meral diaphyseal fractures are rotator cuff iatrogenic injuries. The aim of this study is to evaluate either integrity or mobility of the rotator cuff after surgery.Methods and Materials: 18 surgically treated humeral diaphyseal fractures were prospectively included in the study. All patients underwent osteosinthesys with in-tramedullar nail fixation from December 1990 to April 2005. Mean age was 49 years (range 17-81). Sonographic evaluation included assessment of the supraspinatus, infraspinatus and subscapularis tendons, the subacromial-subdeltoid bursa and the biceps tendon and sheath.Results: In 9 patients, integrity of the rotator cuff was observed. All of them pre-sented a hypoechoic area of scarring (3-7 mm) near a bone notch located in the anteromedial face of the humerus, probably related to nail insertion site. 5 patients with advanced age showed various degrees of rotator cuff tears in both shoulders. 4 presented reduced mobility in the operated shoulder as well. Only 1 patient had a completely normal examination. Of the remaining 3 cases, 1 presented calcifica-tion, 1 congenital muscle and tendinous atrophy, and 1 tendinous heterogeneity (tendinopathy).Conclusion: Osteosynthesis with intramedullar nail fixation of humeral diaphyseal fractures produces a scarred appearance of the rotator cuff. As rotator cuff tears were bilateral and occurred in patients of advanced age, they probably are second-ary to rotator cuff chronic wear, instead of postoperative sequelae.

C-667 Regeneration of semitendinosus tendon harvested for ACL reconstruction: Evaluation using MRI, US and US elastography E.E. Drakonaki, G. Kouvidis, S.D. Yarmenitis, A.H. Karantanas, N. Gourtsoyiannis; Iraklion/GR (drakonaki@yahoo.gr)

Purpose: The purpose of this study is to: a) evaluate the morphology of the re-generated semitendinosus tendon after being harvested for ACL reconstruction using ultrasound (US) and MR imaging (MRI) and b) describe its stiffness using real-time freehand comparative ultrasound elastography (USE).Methods and Materials: Nine patients (mean age 29+8.2 years) with ACL recon-struction using semitendinosus tendon were prospectively examined (mean time from surgery 22.3 months). The regenerated and contralateral semitendinosus tendons were examined using US for evaluating the echostucture. The tendon’s cross-sectional area was measured 4 cm above the joint line using US (9/9 patients) and MRI (7/9 patients). Each measurement was performed 3 times. USE of the ten-dons was performed sagittally and the elastograms were presented as colour-coded (blue-soft, green-medium, red-hard) and as greyscale (white-hard, grey-medium, black-hard) images superimposed on the B-mode image. All elastograms were qualitatively evaluated by two radiologists and interpreted by consensus.Results: There was no statistically significant difference in the cross-sectional area of the regenerated and contralateral tendon as measured by US (t-test, 15.7+7.5, 11.4+1.5 mm2, respectively, p=0.213) and MR (t-test, 13.7+6.5 and 10.4+0.9 mm2, respectively, p=0.312). The regenerated tendon had a fibrillar but less uniform echostructure with less distinct edges and was homogenously hard (red/black), whereas the normal tendon was inhomogenous with hard (red/black) and softer (grey-white/green-blue) longitudinal stripes.Conclusion: Although the regenerated tendon in the late postoperative period has similar size and US and MRI appearance to the normal tendon, it presents with a dif-ferent elastographic pattern which might reflect different mechanical properties.

C-668 How to improve performance of US in exploration of Stener’s lesions: A study with anatomic correlation between US, MR and cadaveric findings E. Pluot, H. Guerini, C. Dumontier, A. Feydy, D. Richarme-Barthelet, J.-L. Drape; Paris/FR (e.pluot@voila.fr)

Purpose: Difficulties of ultrasonographic (US) identification of the adductor apo-neurosis and ulnar collateral ligament of the metacarpo-phalangeal joint (UCL) in Gamekeeper’s thumb have prevented its spreading as a reliable pre-therapeutic imaging modality. Performances of US in this setting are evaluated.Methods and Materials: Two undisplaced and four displaced UCL tears were surgically created in six non-embalmed cadaveric hands. Five unaltered hands were used as controls. T1 and T2-weighted MR images of all specimens were ob-tained in axial or coronal plane. A series of static US images was obtained in both

planes. Measurement of the distance between the medial side of the metacarpal head and the adductor aponeurosis (MHA) was performed. A series of dynamic US images with a repeated flexion of the interphalangeal joint of the thumb was also obtained. Hands were frozen and cut through a band saw into anatomic slices in both planes corresponding to the MR images. MR and US images were compared to the anatomic slices. MHA was compared on coronal views between displaced and undisplaced UCL.Results: UCL and adductor aponeurosis were identified on US in all specimens. The correlation between US and anatomic slices was excellent. The position of the UCL with respect to the adductor aponeurosis was correctly diagnosed in all UCL tears. The median MHA value was significantly reduced in case of displaced UCL compared to undisplaced UCL (1.7 mm vs 3.28 mm, p=0.004).Conclusion: Adductor aponeurosis and UCL are perfectly identified on US explora-tion. Diminished MHA is associated with displaced UCL.

C-669 MR imaging of the skin at 3 Tesla: First experience on healthy volunteers C. Casile, S. Aubry, P. Humbert, B. Faivre, E. Delabrousse, P. Sarlieve, B. Kastler; Besancon/FR (radio.aubry@free.fr)

Purpose: To assess skin MR quality at 3 Tesla. To describe skin anatomy at 3 Tesla. To discuss advantages of 3 Tesla MR imaging of the skin.Methods and Materials: A 3 inch customized surface coil was specially designed and elaborated for our 3 Tesla MR system. Thin sections were obtained with a three dimensional Fiesta acquisition sequence and a two dimensional spin echo T1 sequence. Prospective analysis of the cases was performed twice by two ra-diologists independently. 36 healthy volunteers were included and underwent MR examinations on two skin areas: the face and the calf. Image quality was assessed on visibility of skin layers and artefacts quantification.Results: The use of an intense magnetic field, thanks to its increased signal-to-noise ratio, enables to realise images of the skin with a high spatial resolution (Pixel size=8μ), in a satisfactory acquisition time. Image quality was excellent for the calf with a high intra and inter-observer correlation (Pearson coefficient). Motion artifacts resulted in a small loss in quality and reproducibility for the face.Conclusion: Skin MR is a recent imaging modality still in evaluation. Imaging at 3 T magnetic field allows high spatial resolution imaging of the skin. It has the potential to become in the near future the best non invasive technique to analyse skin characteristics and its diseases.

C-670 Bursitis rather than edema is associated with greater trochanteric pain syndrome: MR imaging findings with clinical correlation E.E. Drakonaki, A.H. Karantanas, E. Apostolaki, N. Gourtsoyiannis; Iraklion/GR (drakonaki@yahoo.gr)

Purpose: The purpose of this study is to determine the probable relationship of greater trochanteric bursitis/edema with the presence of lateral hip tender-ness/pain.Methods and Materials: Every hip MR imaging examination performed in our de-partment within a 3 year period was prospectively evaluated for presence of greater trochanteric bursitis or peritrochanteric edema, using a coronal STIR sequence. In every positive case, the maximum craniocaudal diameter of the distended bursa or the edematous area was measured. History of pain was recorded and the patient was clinically evaluated for trochanderic tenderness to palpation. Patients with previous injections at site were excluded. All MR images were evaluated by a single radiologist. Statistical significance was set at p 0.05.Results: In total, 71 hips (60 patients, mean age 63+7.5 years) were included in the study. Edema was present in 40/71 (56.3%) cases and bursitis in 31/71 (43.7%) cases. In the majority of cases, the patient was asymptomatic (56/70, 78.9%). Trochanteric pain was present in 15/71 (21.1%) cases and coexisted with bursitis rather than with edema (10/15, 77% and 5/15, 33%, respectively, ANOVA, p=0.044). The mean diameter of bursitis/edema was larger in patients with pain than in the asymptomatic group (t-test, 4.02+0.75 mm, 3.21+0.79 mm, respectively, p=0.001).Conclusion: Greater trochanteric bursitis/edema is commonly asymptomatic. Pain is associated with bursitis rather than peritrochanderic edema. The extent of soft tissue involvement is associated with the presence of trochanderic pain, both in cases of bursitis and edema. Clinical correlation is mandatory when evaluating imaging findings.

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C-671 Real time freehand elastography of the normal calf muscles E.E. Drakonaki, S.D. Yarmenitis, A.H. Karantanas, N. Gourtsoyiannis; Iraklion/GR (drakonaki@yahoo.gr)

Purpose: Real-time freehand ultrasound elastography (USE) is a means of evaluating tissue elasticity. Limited data exist on the elastic properties of muscle in vivo. We aim to evaluate the feasibility of USE for studying asymptomatic calf muscles (soleus, medial/lateral heads of gastrocnemius) and to describe their elastographic appearances.Methods and Materials: We prospectively examined 34 normal calfs using USE (Siemens Antares). Each muscle complex was examined 3 times axially at the level of the midcalf and the images were stored as cine-loops. The elastograms were presented as colour-coded (blue-soft, green-medium, red-hard) and as greyscale (white-hard, grey-medium, black-hard) images superimposed on the B-mode image and displayed side-by-side to it. All elastogram-B mode image pairs were qualitatively evaluated by two radiologists and interpreted by consensus.Results: The individual muscles could be identified on the elastograms in all cases with accurate matching between the greyscale and color-coded data. Three distinct elastographic patterns were identified: hard (black/red) soleus with softer (gray/green) gastocnemial heads (pattern 1, /34), hard (black/red) soleus and lateral head with softer (gray/green) medial head (pattern 2, /34) and homogenously hard (black/red) soleus and gastrocnemial heads (pattern 3, /34). All muscle borders were presented as soft areas (white/blue).Conclusion: USE appears as a feasible non-invasive method to evaluate muscle stiffness. Our findings confirm the expected variation in muscle elasticity in the healthy population. Further studies are required to evaluate the clinical role of USE for studying muscle biomechanics in health and disease.

C-672 Real time freehand elastography of the normal quadriceps and patella tendons E.E. Drakonaki, S.D. Yarmenitis, A.H. Karantanas, N. Gourtsoyiannis; Iraklion/GR (drakonaki@yahoo.gr)

Purpose: The tendons’ mechanical properties are an important parameter which potentially influences their vulnerability to injury. Real-time freehand elastography (RTE) is a method to assess the mechanical properties (stiffness) of tissue. The purpose of this study is to describe the elastographic appearances of the quadriceps and patella tendons of asymptomatic volunteers.Methods and Materials: We prospectively examined 28 normal quadriceps and patella tendons (mean volunteer age 29+8.2 years) using RTE with a commercially available ultrasound system (Siemens Antares) modified to perform elastography. Each tendon was examined 3 times at its midsection in longitudinal planes and the images were stored as cine-loops. The elastograms were presented as colour-coded (blue-soft, green-medium, red-hard) and as greyscale (white-hard, grey-medium, black-hard) images superimposed on the B-mode image and displayed side by side to it. All elastogram-B mode image pairs were qualitatively evaluated by two radiologists and interpreted by consensus.Results: The tendons were identified on the elastograms in all cases. There was accurate matching between the greyscale and color-coded data. All tendons dem-onstrated a striated appearance. The quadriceps tendons were hard, with thick hard (black/red) longitudinal stripes and only a few scattered softer (white/green) areas. The patella tendons were predominantly soft (white/green), with a few thin hard (black/red) stripes more prominent at the tibial insertion of the tendon.Conclusion: Although the patella and quadriceps tendons act as an anatomical and functional unit, they present with different elastographic appearances, possibly reflecting differences in biomechanical strain.

C-673 MR morphology of alar ligaments in asymptomatic subjects evaluated by 3 Tesla P. Schmidt, H.P. Burmeister, J. Boettcher, H.-J. Mentzel, W.A. Kaiser; Jena/DE (drpschmidt@med.uni-jena.de)

Purpose: As no data of 3 T MR imaging of alar ligament imaging is yet available, the purpose of this study was to assess the variation of the magnetic resonance appearance of the alar ligaments in asymptomatic individuals.Methods and Materials: 104 healthy subjects (53 female, 51 male) with a mean age of 27.6 years (range 18-73 years) underwent MR imaging at 3.0 T scanner using a T2-weighted turbo spin echo 3 D sequence with 0.8 mm isotropical voxels (acquisition time, 461 seconds; acquisition type, 3D; repetition time, 3000 ms; echo time 354 ms; number of averages, 1; number of slices, 176; slice thickness,

0.8 mm; matrix, 256 x 256; field of view, 210 mm; flip angle, 180°). MR findings were analyzed independently by 2 radiologists regarding homogeneity, symmetry, signal intensity, shape and spatial orientation of the alar ligaments, differences were resolved in conference.Results: Alar ligaments could be detected in all subjects. Asymmetry was found in 52%, ligament signal inhomogeneity in 42%, signal intensity variation in 67%, shape differences in 53% and differences in their spatial orientation in 23 %. 2 subjects revealed incidentally a partial rupture of one ligament.Conclusion: 3 Tesla MRI provides excellent visualization of the alar ligaments. Struc-tural alterations of the alar ligaments are frequent findings in asymptomatic individuals. This finding limits the clinical relevance of structural alterations in the identification of the source of neck pain in symptomatic patients after whiplash injury.

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C-674 Chordoma: Radiologic-pathologic correlation - global view and main details P. Diez, R. Cano, L. Ibañez, M. Navallas, R. Navas, P. Manjon; Madrid/ES (patriciadiezm@yahoo.es)

Learning Objectives: To update and review the chordomas from a radiological point of view, with clinical and pathologic correlation. To illustrate the pathological findings and radiological features essential to reach a correct diagnosis.Background: Chordomas are relatively uncommon tumours of low or intermediate malignancy. They are located almost exclusively in the midline and are supposed to originate from embryonic remnants of the primitive notochord. They can be viewed through a simple X-ray (as destruction of the involved bone) and CT (as a centrally located, well-circumscribed, soft-tissue mass with associated bone destruction). Nevertheless, it is the MR image that allows the best characterization, delineation and relation to adjacent structures.Procedure Details: We have evaluated all the cordomas that were diagnosed in our hospital in the last 15 years, including only the ones which have clinic history and evolution, X-ray, CT and MRI (including some of them with arteriography) and pathologic correlation. We present 22 cases with pathologic-radiologic correlation (11 intracraneal, 5 spinal and 6 sacral). Besides the classic chordoma the follow-ing variants showed: condroid chordoma, dedifferentiated chordoma, sarcomatoid chordoma. Having updated and reviewed the international literature about chordo-mas, we provide here the main details and a global view of these tumours (not only depending on the localization or histological type as traditionally are classified).Conclusion: With this exhibit the radiologist will have a complete understanding of chordomas, including histopathology and radiological features.

C-675 Incidental spinal osteosclerotic lesions: A pictorial review T. Nishiguchi, T. Nakayama, K. Mochizuki, Y. Inoue; Osaka/JP (tomokazu-n@med.osaka-cu.ac.jp)

Learning Objectives: 1. To recognize and categorize clinical and imaging mani-festations of incidentally found spinal osteosclerotic lesions (SOL). 2. To discuss the radiological approach and clinical management for these lesions.Background: Recent radiological screening studies have detected various SOL. Although osteosclerotic changes in the spine mostly suggest a lesion with a chronic and dormant clinical course, some lesions need to be differentiated from malignant lesions like osteoblastic metastasis or Hodgkin lymphoma, and neces-sitate appropriate management. This exhibit, describing such SOL in our case records, includes: discovertebral degenerative disease, facet osteoarthritis, osteoid osteomas, osteoma, Paget’s disease, chronic osteomyelitis, idiopathic segmental sclerotic lesion caused by subclinical trauma, benign notochordal cell tumor, osteopetrosis, calcium pyrophosphate deposition disease (CPPD), amyloidosis, seronegative osteoarthritis, nephrogenic osteodystrophy, and diffuse idiopathic skeltal hyperostosis (DISH).Procedure Details: Incidental SOL were categorized and analyzed by epidemiol-ogy, pathogenesis, clinical symptoms, and imaging patterns. The relevance of clinical and imaging manifestations with histopathological findings and clinical outcome were investigated extensively. We also present the case-based review of common to uncommon SOL, utilizing diverse imaging techniques including diffusion-weighted image and fluorodeoxyglucose-positron emission tomography, and discuss image interpretations and clinical management for these lesions.Conclusion: SOL incorporate various etiologies from non-tumoral processes to malignant tumor. Awareness of these imaging and clinical features will enhance the correct diagnosis and appropriate management of SOL.

C-676 Benign bone tumors of the spine: A pictorial review M. Seco1, O. Vaz1, J. Brito2, B. Graça1, A. Peres1, F. Caseiro-Alves1; 1Coimbra/PT, 2Ponta Delgada/PT (migseco@sapo.pt)

Learning Objectives: To review the imaging findings of benign bone tumors of the spine emphasizing their differential diagnosis.Background: Benign tumors of the spine are relatively rare when compared to other entities such as metastases or multiple myeloma. The identification of a solitary spinal bony lesion challenges the differential diagnosis, and imaging is instrumental for clinical decision making. Non-specific back pain is the most com-mon and often sole complaint.

Imaging Findings: Using a multimodality approach, benign tumors of the spine will be discussed enrolling haemangioma, osteoid osteoma, osteoblastoma, aneu-rysmatic bone cyst, giant cell tumor, enostosis, osteochondroma and eosinophilic granuloma.Conclusion: Radiological findings quite often are sufficiently specific to address the correct diagnosis. The combination of cross-sectional modalities (CT/MR) as-sist X-ray techniques in the differential diagnosis and convey staging information including foraminal or spinal extension of the process.

C-677 Destructive spondyloarthropathy in long-term haemodialysed patients: Imaging findings S.J. Theodorou, D.J. Theodorou, D. Resnick; San Diego, CA/US

Learning Objectives: To call attention to an unusual pattern of spondyloarthropathy in patients with chronic renal disease. To illustrate and discuss the distinct spinal alterations of destructive spondyloarthropathy associated with haemodialysis. To improve recognition of the imaging characteristics of destructive spondyloarthropa-thy for the benefit of early diagnosis and appropriate clinical management.Background: Destructive spondyloarthropathy is an unusual complication seen in middle-aged and elderly patients with chronic renal disease who have been undergoing long-term haemodialysis. Although the pathogenesis of destructive spondyloarthropathy remains unclear, the disorder is thought to relate to a hae-modialysis-associated amyloidosis.Imaging Findings: Single or multiple spinal levels reveal rapidly progressive radiographic abnormalities characterized by narrowing or loss of intervertebral disc space, erosion of subchondral bone in adjacent vertebrae, sclerosis, facet involvement with subluxation, and vertebral body compression. Contiguous or distant vertebrae, especially in the cervical or lumbar segment are involved. The findings may resemble infection, neuropathic osteoarthropathy, severe interver-tebral (osteo)chondrosis, or calcium pyrophosphate dihydrate crystal deposition disease. CT images usually reveal osteolytic areas, subchondral bone sclerosis, and minimal osteophytosis. Vertebral subluxation and spinal cord compression may occur. Magnetic resonance imaging may disclose low signal intensity in the involved intervertebral discs and adjacent vertebral endplates on both the T1- and T2-weighted images. Persistence of low signal intensity on T2-weighted images along with the absence of paraspinal mass permits elimination of infection.Conclusion: Knowledge of the variable imaging appearances of destructive spon-dyloarthropathy is important for appropriate clinical assessment of the condition and prevention of neurologic impairment due to compressive myelopathy.

C-678 Role of imaging in the assessment and management of scoliosis S. Ramamurthy, V. Rachapalli, N. Goyal, S. Rashid, S. Singh, I.P. Gunatunga, S. Ahuja, K. Mukerjee; Cardiff/UK (sidi.rashid@yahoo.co.uk)

Learning Objectives: Scoliosis is defined as a lateral deviation from the normally straight appearance of the spine. Diagnostic imaging plays a vital role in evaluating etiology, choice of treatment, and prognosis. Once treatment is instituted, imaging is also critical for monitoring the outcome. The aim of this poster is to provide an overview of the etiology, clinical features and imaging findings of scoliosis.Background: Though scoliosis could be a manifestation of an underlying disease, most cases are idiopathic. Imaging plays an important role in determining underly-ing etiology and monitoring the changes in deformity of the growing spine. Plain radiographs and MRI are most widely used in evaluating scoliosis.Imaging Findings: Plain radiography is vital in investigating scoliosis. Its main role is to assess the extent of curvature of the spine and maturity of the skeleton from the iliac apophysis (Risser index). MRI is paramount in diagnosing any underlying spinal infection or tumour. CT is of limited use, particularly in the young patient with cartilaginous spine. The poster provides an overview of the assessment of the extent of deformity on plain films and the role of MRI in assessing scoliosisConclusion: Beginning with the identification of the underlying pathology, or not, as in cases of “idiopathic” scoliosis, radiology plays a vital part in treatment considerations and decision making. The radiologist needs a good understanding of the nature of the disease and its sequelae in order to help the surgeon achieve the best possible result.

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C-679 MR imaging features of spinal lymphoma L. Zhou, W. Peng, W. Yang, F. Tang; Shanghai/CN (zhoulp-2003@163.com)

Purpose: To analyze MR imaging manifestation of spinal lymphoma in order to deepen the recognition of this rare disease.Methods and Materials: 45 patients with pathologically or clinically proven spinal lymphoma who underwent MRI examination were reviewed. Patients were 17~76 years old (mean = 48); 26 were men and 19 were women. 5 cases were primary non-Hodgkin lymphoma (NHL), 40 cases were secondary with 9 Hodgkin lymphoma (HL) and 31 NHL (27 B-cell type NHL and 4 T-cell type NHL).Results: 27 cases manifested as bone destruction with 23 of them having paraver-tebral soft masses imbedded vertebrae and the extent of soft masses more diffuse than that of bone destruction were founded in 18 cases. 6 cases manifested as soft masses without obvious bone destruction, of which 5 cases had soft masses imbedded vertebrae and communicated paravertebral and epidural spaces through intervertebral foramen. 9 cases of secondary spinal lymphoma had signal intensity changes of bone marrow without obvious cortical bone destruction and soft mass. 3 cases of secondary spinal lymphoma had spinal cord swelling and signal intensity changes. After intravenous injection of contrast media, the soft masses showed mild or moderate enhancement without remarkable cystic degeneration and necrosis.Conclusion: Most of the spinal lymphoma is the secondary B type NHL with com-plex MRI manifestation. Osteolytic lesion with contiguous paravertebral soft mass imbedded vertebrae with a mild or moderate enhancement without remarkable cystic degeneration and necrosis may suggest the diagnosis of this rare disease.

C-680 Depiction characteristics and scan method for extravasation in the sacrum in CT studies following pelvic trauma I. Fujimura, K. Sagara, S. Nishiike, K. Sakashita; Izumisano/JP (fujimura@sccmc.izumisano.osaka.jp)

Purpose: Injury to the middle and lateral sacral arteries and sacral venous plexus is the main cause of retroperitoneal bleeding following pelvic trauma. CT is generally used to detect extravasation, but its diagnostic capabilities are poor compared to angiography. We investigated whether this is due to partial volume effects from the sacrum.Methods and Materials: MPR images were generated in 204 patients who underwent pelvic multislice CT. The angle between the anterior aspect of the sacrum and the slice plane was measured. Age and gender differences were also examined. The effects of slice thickness, angle between the sacrum and the slice plane, and MPR on the diagnosis of extravasation from the lateral sacral artery were investigated.Results: The mean angle between the anterior aspect of the sacrum and the MPR slice plane was 23.9° in women and 25.8° in men (range: 63.4° to 0°). No significant differences due to age were observed. Diagnostic capabilities varied depending on the slice thickness: evaluation was possible at a slice thickness of 3 mm or less, but impossible at 5 mm or more. It was also found that the smaller the angle between the anterior aspect of the sacrum and the slice plane, the poorer the diagnostic capabilities. The diagnostic capabilities of MPR were improved by generating planes perpendicular to the sacrum.Conclusion: In CT following pelvic trauma, since the depiction of extravasation in the sacrum is affected by partial volume effects from the sacrum, a thinner slice thickness and MPR should be used.

C-681 Three-dimensional magnetic resonance imaging of the cervical spine T. Meindl1, S. Wirth1, S. Weckbach1, C. Born1, O. Dietrich1, M. Reiser1, S. Schoenberg2; 1Munich/DE, 2Mannheim/DE (thomas.meindl@med.uni-muenchen.de)

Purpose: To compare a three-dimensional (3D), high-resolution turbo spin echo (TSE) T2w sequence with variable flip angle distribution with conventional two-dimensional (2D) TSE T2w and gradient recalled echo (GRE) T2*w sequences for imaging of the cervical spine.Methods and Materials: The cervical spine of 15 healthy volunteers was exam-ined by means of an isotropic 3D TSE sequence at 1.5 T. The sagittally acquired dataset and its axial reformations were compared to a 2D T2w sequence, scanned in sagittal and axial orientation and an axial 2D GRE T2*w sequence. Spatial resolution of the 3D sequence was 0.9 mm and of the 2D sequences 3.0 mm. Signal-to-noise and contrast-to-noise ratio (SNR, CNR) were evaluated. Two independent readers rated visibility of ten anatomical structures. Artefacts were assessed by a 4- point scale.

Results: Sagittal 3D and 2D TSE T2w yielded similar SNR and CNR values. Three-dimensional T2w provided better delineation of nerve roots, neural foramina and intraforaminal structures (p 0.05). Axial 3D reformations produced superior results in terms of visibility of most anatomical structures compared to axial 2D T2w and comparable results to GRE T2*w concerning the spinal cord, intraspinal nerve roots, intraforaminal strucures and intraforaminal fat. GRE T2*w was superior in depicting cord anatomy (p 0.05). Artefacts were more pronounced in 2D T2w.Conclusion: Acquisition of an isotropic data set using 3D TSE T2w with variable flip angles along the echo train is feasible in the cervical spine in healthy volunteers. Delineation of anatomical structures is superior and SNR and CNR comparable to 2D T2w.

C-682 Spinal CT perfusion: Possible clinical applications N. Valle, J. Izquierdo, E. Marco de Lucas, A. Fernández Flórez, I. Bañales, J. Crespo del Pozo, G. Blanco, M. Pelaz, A. Gutiérrez, A. González Mandly; Santander/ES (radmle@humv.es)

Purpose: To describe the technique and main possible clinical applications of spinal CT perfusion, a new application that provides complimentary functional information about spinal pathology.Methods and Materials: CT perfusion is a technique frequently used in the man-agement of acute strokes. In addition, several other reports have demonstrated its usefulness for the study of other anatomic areas including rectal or cervical lesions. However, there are no reports about its possible application for spinal pathology.Results: CT perfusion can be performed in the evaluation of tumoral lesions in order to obtain important diagnostic information. We have reviewed our experience with 34 cases performed at our hospital, including tumors (metastasis, osteoid os-teomas, chordoma, etc.) where it differentiates between high vascular or avascular lesions and helps to select the better location for a needle biopsy. Other lesions where CTP might be useful are spondylodiskitis, postsurgical complications, etc. In addition, we review the main possible adverse points of this technique including extra radiation dose, imaging artifacts and low spatial resolution.Conclusion: Perfusion CT can provide very useful additional information in the management of different spinal lesions. It is a fast and easy technique with no major side effects.

C-683 Hyperextension spine fractures in ankylosing spondylitis or diffuse idiopathic skeletal hyperostosis: Spectrum of imaging findings at CT-scan and MRI R. Campagna, F. Thevenin, D. Richarme, A. Feydy, H. Guerini, J.-L. Drape; Paris/FR (rcampagna@free.fr)

Purpose: Spinal fractures in ankylosing spondylitis (AS) and diffuse idiopathic skel-etal hyperostosis (DISH) generally occur spontaneously or after low-energy trauma and are difficult to diagnose with plain radiograph. The purpose of our investigation was to describe CT and MRI radiologic features of these fractures.Methods and Materials: We reviewed 10 spinal fractures in 10 patients (8 males, 2 females, mean age 60 year, 2 DISH and 8 AS). MDCT-scan was performed for all patients, 3D volume rendering in 5 cases, and MRI in 4 patients. We compared MDCT, MRI radiologic features, and the multiplanar reformat to improve diagnostic performance.Results: Fractures were located in the lower cervical spine in 4 patients (C5-C6-C7), in the lower thoracic spine in 3 patients (T10-T11-T12), and in the lumbar spine in 3 (L1-L2-L4-L5). For all cases, only one spinal level was involved. Fractures involved both vertebral body and disc (7 patients), or the disc only (3 patients). Posterior arch was involved in all cases. Air in the intervertebral space was noted in 3 cases, fluid-like collection and callus formation was found in 2 patients, mimicking tumor or infection. Sagittal or coronal plane deformity was noted in 2 patients. MRI diagnosed spinal cord injuries in 2 patients.Conclusion: MR or CT-scan imaging shows fractures in AS and DISH that may not be clear or detectable by using radiography. A good knowledge of these unusual spine fracture signs (air, fluid collection, spine deformity, callus formation, etc.) is needed to detect and make a diagnosis of these ankylosed spines.

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Miscellaneous

C-684 Reduction of metal artefacts in musculoskeletal MR imaging J.E. Vandevenne1, K. Butts-Pauly2, P.K. Lang3, P.M. Parizel4, F.M.H.M. Vanhoenacker5; 1Genk/BE, 2Stanford, CA/US, 3Boston, MA/US, 4Antwerp/BE, 5Duffel/BE (vdvennej@hotmail.com)

Learning Objectives: 1. To illustrate reduction of metal artefacts in musculoskeletal MR imaging. 2. To provide a brief theoretical understanding of the cause of metal artefacts. 3. To demonstrate effects of readily adjustable parameters for metal artefact reduction including use of appropriate sequences, imaging parameters, patient positioning, and view angle tilting.Background: Metallic hardware is frequently encountered in postoperative mus-culoskeletal MR imaging, causing susceptibility artefacts and impairing evaluation of adjacent structures. Effects of adjustable parameters are demonstrated both in a volunteer with a titanium screw and a saline bag attached to the shoulder and in an in vitro experiment using a hip prosthesis.Imaging Findings: Positioning of the patient with the long axis of the metallic hardware parallel to B0, use of fast spin echo sequences, use of inversion recovery fat suppression, swapping phase and frequency encoding direction, use of view angle tilting, increasing the read-out bandwidth, and decreasing voxel size all are beneficial to reduce metal artefact. Increased image noise when increasing the gradients is a trade-off. Fat suppression should be done using inversion recovery (STIR) technique only to avoid unintentional water suppression near metallic hardware as seen with spectral fat suppression.Conclusion: Knowledge of the presence and position of metallic hardware position within the musculoskeletal system is the key to anticipate how to deal with metal artefacts. Adjusting patient position, use of fast spine echo and STIR sequences, increasing all imaging gradients and applying view angle tilting are very useful to reduce metal artefact.

C-685 Imaging findings in deep and generalized morphea (localized scleroderma) M.S. Horger, G. Fierlbeck, J. Fritz, M. Vogel, C.D. Claussen; Tübingen/DE

Learning Objectives: To illustrate the spectrum of MR-findings in morphea.Background: Morphea refers to a number of different autoimmune conditions characterized by skin thickening with increased collagen deposition. In morphea, the lesions are usually limited to the skin and subcutaneous fatty tissue, but they can extend over muscular fascia, muscle tissue, tendons, joint synovia and even bone marrow.Imaging Findings: MR-imaging findings in the inflammatory stage of this disorder consist of thickening of dermis and infiltration of subcutaneous fatty tissue with increase signal intensity on T2-weighted of the adult and contrast enhanced T1-weighted images. Collagen tissue involves fascia and musculature demonstrating different degrees of infiltration expressed similarly by increased signal intensity on T2-weighted and contrast enhanced T1-weighted images. In time, the bone becomes involved showing particular MR-imaging features. Intense signal is seen on T2-weighted and contrast enhanced T1-weighted images usually following the subcortical bone. Following skin induration and contractures, misalignment of the fingers and toes occur. Mild joint and tendon sheath synovitis is usually found in these patients. Despite generalized synovial inflammation, bone erosions are not expected in patients with morphea. Cutaneous, muscular, fascial and even osse-ous changes are in part reversible in patients with favourable response to therapy, e.g. following chemotherapy with subsequent autologous hematopoietic stem cell transplantation (HSCT).Conclusion: Imaging features in morphea are not specific but they reflect patho-morphological changes of this rare disorder and enable a complete assessment of the disease extent including depth infiltration and activity.

C-686 Diffusion-weighted MR imaging in the musculoskeletal pathology: Is it useful? E. Balliu, I. Peláez, J. Vilanova, A. Gelabert, M. Boada, J. Puig, S. Remollo, J. Barceló, S. Pedraza; Girona/ES (mariaboada0805@hotmail.com)

Learning Objectives: To show the usefulness and limitations of the Diffusion-Weighted MR Imaging (DWI) when applied to the main musculoskeletal system entities, such as, infectious, traumatic, degenerative or tumoral pathologies.Background: Diffusion sequences provide dynamic and microscopic information in addition to the static and macroscopic information provided by conventional

sequences. The potential role of DWI in the musculoskeletal system is still being investigated. Since June 2005, we are including a DWI sequence in our musculo-skeletal protocols. Qualitative and quantitative information using ADC (Apparent Diffusion Coefficient) values can be obtained using DWI.Procedure Details: Diffusion images were acquired using a fat-suppression spin-echo-type multishot echo-planar imaging sequence (b=500 s/mm2). We present and illustrate in the exhibit our results from our series of 40 patients between October 2005 and November 2006. The series was used to study the differentiation on DWI between malignant and benign spine bone marrow lesions. We also illustrate the usefulness of this sequence in: 1. The evaluation of lumbar degenerative disease. 2. The evaluation of post-therapeutic changes and monitoring of treatment of malignant pathology. 3. The addition of useful information to the differential diagnosis of soft tissue tumors. 4. The inclusion in a whole body imaging protocol.Conclusion: DWI allows a qualitative and quantitative assessment in the musculo-skeletal system pathologies, adding complementary information to the conventional sequences. DWI plays a promising role in the evaluation of musculoskeletal pathol-ogy and could be included in the routine MR imaging protocol.

C-687 Neurocristopathies: Several soft tissue and musculoskeletal tumors derived from neural crest S. Gonzalez Ortiz, A.I. Garcia, M.S. Prevedoni, B. Paño, S. Puig; Barcelona/ES (aifosgeo@yahoo.es)

Learning Objectives: 1. To review cases of musculoskeletal (MS) and soft tis-sue tumors derived of neural crest (NC) originated cells. 2. To describe the term “Neurocristopathy” as an unifying concept to describe pathology arising for neural crest. 3. To illustrate “simple” and “complex” neoplastic neurocristopathies (NCP) of soft tissue and MS system.Background: The NC differentiates into a wide variety of cellular types: different neurons of periferic system, glial cells, chondrocytes, osteocytes, melanocytes, chromaffin cells, odontoblasts, Merkell cells, parafollicular cells of thyroid, skeletal and smooth muscle cells. The defective NC development gives rises to a wide number of alterations. The term “NEUROCRISTOPATHY” references disorders resulting from aberrations in the growth and development of NC structures. It can be “simple” (unifocal pathology) or “complex” (multifocal association). Typically, there are two major categories, neoplastic and dysgenetic.Imaging Findings: We present RX, CT AND MR images of simple and com-plex NCP with MS and soft tissue tumors (neurofibroma, neurofibrosarcoma, schwannoma, malignant schawannoma, rhabdomyosarcoma, chondrosarcoma, ostheosarcoma, ameduloblastoma, melanoma, leiomioma and leiomiosarcoma).Conclusion: Understanding the concept of NCP helps us to remind of the possibility of a NCP in a patient with neural crest tumors. Radiologist can be aware, therefore, of the potential existence of other tumors of the same origin.

C-688 Metartarsalgia: An ultrasound atlas H. Guerini, G. Morvan, A. Feydy, R. Campagna, F. Thevenin, D. Richarme, A. Chevrot, J.-L. Drapé; Paris/FR (henri.guerini@cch.aphp.fr)

Learning Objectives: Purpose an atlas of ultrasound in metatarsalgia.Background: Metatarsalgia is explained as localized or more diffuse tenderness beneath the metatarsal heads. The pain may be attributed to various etiologies.Procedure Details: Many disorders produce discomfort in the metatarsal region of the forefoot. These disorders include traumatic lesions of the soft tissues and bones (plantar plate disruption, stress fracture), Freiberg infraction, arthritis, non neoplastic soft-tissue masses (ganglion cyst, bursitis, Morton neuroma). However, ultrasound imaging has proved useful in detecting the numerous soft-tissue and early articular disease that occur in this portion of the foot. Frequently, ultrasound imaging allows a specific diagnosis based on the location and morphologic features of the abnormality.Conclusion: Consequently, ultrasound imaging is increasingly being used to evalu-ate patients with forefoot complaints.

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C-689 3.0 T MRI findings of heel pain causative lesions L. Guimaraes1, A.S.R. Preto2, M. Pimenta2, A. Silva2, A. Vieira2; 1Viseu/PT, 2Porto/PT (sofiapreto@hotmail.com)

Learning Objectives: To illustrate the MR imaging (3.0 Tesla) characteristics of hindfoot pain causative lesions.Background: Hell pain is a common orthopaedic clinical scenario. It is often difficult to elicit a clear history of related trauma. Accurate and fast diagnosis of hindfoot le-sions can significantly improve clinical outcome with reduced complication rates.Imaging Findings: Imaging findings of a patient with hindfoot pain are as numer-ous as its causative lesions. The disorders include plantar fascial lesions (fasciitis, rupture, fibromatosis, xanthoma), tendinous lesions (tendinitis, tenosynovitis), osseous lesions (fractures, bone bruises, osteomyelitis, tumors), bursal lesions (retrocalcaneal bursitis, retroachilleal bursitis), tarsal tunnel syndrome, and heel plantar fat pad abnormalities. With its superior soft-tissue contrast resolution and multiplanar capability, magnetic resonance imaging (especially with 3.0 Tesla equipment and its higher signal-to-noise ratio) can help determine the cause of heel pain and help assess the extent and severity of the disease in ambiguous or clinically equivocal cases.Conclusion: In conclusion, MRI provides all the necessary diagnostic information for evaluation of the complex anatomy of the hindfoot. Thanks to its high spatial and contrast resolution and multiplanar imaging capabilities, accurate evaluation with MRI is mandatory in order to provide early diagnosis and to determine the most appropriate management.

C-690 Hybrid angio and dynamic contrast-enhanced MR for musculoskeletal evaluation X. Merino-Casabiel, R. Dominguez-Oronoz, S. Gispert-Herrero, V. Pineda-Sánchez, R. Monmany-Badia, G. Garrido; Barcelona/ES (xavier.merino@idi-cat.org)

Learning Objectives: 1) To describe the basic principles and the imaging technique (sequence parameters, imaging plane, etc.) of the Hybrid-MRA. 2) To review and illustrate the clinically useful information provided by the Hybrid-MRA in different clinical settings.Background: The local anatomic relationships, specifically vascular arterial and venous, are of critical importance for the musculoskeletal (MSK) tumor treatment strategy design. In addition, dynamic contrast-enhanced MRI provides clinically useful information for soft tissue and bone tumors evaluation (tissue vascularization-perfusion, capillary permeability, etc.) Recent technical developments have greatly accelerated MR image acquisition, improving the temporal resolution of CE MRA. The information provided with this time-resolved technique can be evaluated for “conventional/time-resolved” MRA or for dynamic tumor behaviour evaluation.Procedure Details: This exhibit describes and illustrates the technique and some of the clinical scenarios in which high temporal resolution imaging can improve its diagnostic value. 1-Time-resolved MRA: basic principles. 2-Dynamic contrast-enhanced MRI: basic principles. 3-Hybrid dynamic MRA: 3.1-basic principles, 3.2-technique. 4-Clinical applications: 4.1-anatomic vascular information (map for surgery), 4.2-tumoral tissue characterization: identification and evaluation of highly-vascular viable areas of tumor (biopsy area-selection, pre-surgery emboliza-tion, response monitorization to preoperative chemoteraphy, etc.), 4.3-detection of residual/recurrent tumor after therapy.Conclusion: Time-resolved imaging is a helpful tool for MSK tumor evaluation because with the same data anatomic vascular information (morphologic) and “time-resolved” (dynamic) vascular and tumoral information is provided.

C-691 Imaging of the nailbed and peronychium: MRI atlas T. Piedra Velasco, J. Arnáiz García, A. Canga Villegas, R. García Barredo, A. García Bolado, M. Pelaz Esteban; Santander/ES (tatianapiedra@yahoo.es)

Learning Objectives: To review the most characteristic MRI findings of nail and per-onychium pathology with special emphasis on tumors and soft tissue masses.Background: This exhibit presents the normal appearance and main pathologic conditions of nail and peronychium imaged with MR. MRI can help to accurately define the location and limits of nail pathology before treatment. Ultrasound may also be a complementary tool in nail evaluation.Imaging Findings: A. Normal anatomy of the nail plate. B. MRI atlas of the nail and perionychium. C.MRI appearance of common benign and malignant nail tumors (glomus tumor, mucoid and inclusion cysts…). D. Inflammatory and infectious dis-eases affecting the nail unit. E. Uncommon nail pathology. F. “Syndromes involving

the nails” (nail-patella syndrome and other genetic disorders affecting the nails). G. MRI versus ultrasound, which one depicts nail pathology best?.Conclusion: MRI is the most appropriate imaging technique to depict nail pathol-ogy, especially in the case of tumors and soft-tissue masses.

C-692 Update on radiologic evaluation of musculoskeletal infections in immunocompromised patients C. Vázquez Olmos, M. Martínez Fernández, A. Blanco Barrio, C. Ordoñez González, J. Plasencia Martínez, C. Ortiz Morales; Murcia/ES (ca.olmos@yahoo.es)

Learning Objectives: To show the different musculoskeletal infections that can affect immunocompromised patients and the characteristic appearances on different imaging modalities. To describe the potential applications of the imaging techniques in the diagnosis and management of each pathological condition.Background: Musculoskeletal infections are common in clinical practice. The immunocompromised patient is susceptible to opportunistic and nonopportunistic infections. Although not as common as complications involving other systems, such as pulmonary and central nervous system abnormalities, musculoskeletal infections affecting the skin, underlying soft tissues, bones and joints are the most frequent complications in these patients.Procedure Details: We present 31 cases with secondary inmunosuppression (alcoholism, tuberculosis, human immunodeficiency virus infection, diabetes mellitus and cancer) that developed muskuloskeletal infections including cellulitis, abscess, necrotizing fascitiis, tenosynovitis, septic bursitis, osteomyelitis, septic arthritis and spondylodiscitis.We review recent literature and describe the appearance of these pathologies in radiographs, ultrasound, computed tomography and magnetic resonance examina-tions. We show representative examples from our own findings and also analyze the clinical presentation, associated risk factors and implicated microorganisms.Conclusion: Currently, amongst immunocompromised patients, there is a high prevalence of musculoskeletal infections. Musculoskeletal imaging plays an im-portant role in early diagnosis and appropriate treatment. Although biopsy is often necessary for the final diagnosis, it is important for the radiologist to be familiar with the different types of musculoskeletal infections so that an adequate differential diagnosis can be made.

C-693 Musculoskeletal TB: The return of the great pretender N. Karunanithy; London/UK (nara121@doctors.org.uk)

Learning Objectives: Illustrate the imaging features of musculoskeletal tubercu-losis (TB) on plain film, ultrasound, CT and MRI with emphasis on some of the more atypical presentations.Background: It is estimated that worldwide, 2 million people die of TB every year. There has been a steady increase in the incidence of TB in the UK since the mid - 1980s and London has seen a large increase in the last decade. Despite this, the musculoskeletal manifestations of TB are rarely encountered in day-to-day practice. The clinical presentation in these patients is often non-specific and of insidious onset. TB could therefore be overlooked as a potential diagnosis.Imaging Findings: We present examples of arthritis, osteomyelitis, tenosyno-vitis and soft tissue infections proven to be due to TB. Due to the nature of the initial presentation in these cases, TB had initially not been thought to be a likely diagnosis.Conclusion: Familiarity with the appearances of musculoskeletal TB and knowl-edge of high-risk patient groups will help in the prompt diagnosis and treatment of this condition.

C-694 Imaging of bone and joint tuberculosis W.C.G. Peh1, H.E.L. Teo1, N. Pattamapaspong2; 1Singapore/SG, 2Chiang Mai/TH (wilfred.peh@gmail.com)

Learning Objectives: To appreciate, using imaging, the pathogenesis of tuber-culosis of the joints, long bones and spine, highlighting the differences between children and adults. To review the usefulness of various imaging modalities in the diagnosis of tuberculosis of the bone and joints.Background: There is an increasing incidence of tuberculosis worldwide, with bone and joint involvement accounting for up to 30% of cases of extra-pulmonary tuber-culosis. The most common manifestations of skeletal tuberculosis are spondylitis, arthropathy and osteomyelitis. Its clinical features may be non-specific and often mimic a variety of other diseases. Imaging has an important role in the diagnosis of tuberculosis of the bones and joints.

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Imaging Findings: Skeletal tuberculosis may spread hematogeneously from a primary pulmonary lesion or a quiescent pulmonary or extra-pulmonary site, result from reactivation of a previous infective focus, or be directly innoculated. Tuberculous spondylitis involves the intervertebral disc only late in the disease. Subligamentous spread of the infection frequently leads to multiple levels of contiguous vertebral body involvement. Extension of the disease into the paravertebral or extra-dural space may occur. Tuberculous arthritis usually occurs from spreading to the joint from an adjacent osteomyelitic focus. Tuberculous osteomyelitis may appear as destructive or cystic well-defined lesions, with varying amounts of sclerosis and periostitis. Bone expansion with exuberant periosteal new bone formation produces spina ventosa or dactylitis.Conclusion: Knowing the pathogenesis of tuberculosis and its imaging appear-ances in the skeletal system would aid in its early diagnosis.

C-695 Musculoskeletal non-oncological imaging with PET J.P. Mazzie1, S. Smith1, P. Gerard2, B. Dasgeb1, L.M. Fayad1, S. Shankman2; 1Baltimore, MD/US, 2Brooklyn, NY/US (jmazzie@gmail.com)

Learning Objectives: The purpose of this presentation is to present a variety of non-oncological musculoskeletal (MSK) findings that we have encountered in our practice on PET CT to alert the radiologist to the presence and appearance of such entities.Background: Currently PET is the gold standard for imaging in the oncological setting; however, often radiologists come across lesions that are non-malignant and often incidental. It is imperative that the interpreting radiologist does not mistake these benign conditions as it can have significant consequence on patient care.Procedure Details: The wide array of cases that we will present include: benign muscular uptake related to glucose levels and recent exercise, rotator cuff pathology such as tears and calcific tendinosis, and meniscal pathology. Additionally, benign soft tissue lesions such as sebaceous cysts, lipomas and other skin conditions will be discussed. Benign osseous lesions will also be reviewed including degenera-tive and non-degenerative arthropathies, fractures and osteomyelitis. Cases will be correlated with a wide array of other imaging modalities, including CT and MRI as appropriate.Conclusion: There are many non-oncological MSK findings on PET imaging today, which the radiologist should be aware of to avoid a possible inaccurate diagnosis.

C-697 Unusual sites in primary extranodal involvement of non-Hodgkin lymphoma: Spectrum of imaging findings G.E. Daskalogiannakis, N.A. Courcoutsakis, A. Anastasiadis, A.G. Spanoudaki, K. Tsatalas, P.K. Prassopoulos; Alexandroupolis/GR

Learning Objectives: To illustrate the spectrum of imaging findings in unusual sites of extranodal involvement of non-Hodgkin lymphoma (NHL). To discuss differentials from other neoplasms or non-neoplastic conditions.Background: Although there have been described cases of lymphomas in nearly all organ systems, the proportion is variable, with some sites being very common and others unusual. The gastrointestinal tract, spleen and Waldayer ring are the most common extra-nodal sites of NHL. In this exhibit, we present the imaging findings (on CT, MRI, US) of primary lymphomatous localization in uncommon sites. Head and neck (maxillary sinus, orbit), skeletal system (iliac bones, tibia, tarsal and shoulder bones), thorax (lungs, pleura), CNS (brain), and genitourinary system (testis) as primary areas of involvement are demonstrated.Imaging Findings: The imaging appearance of extranodal NHL was unspecific, masquerading a broad spectrum of signs. Head and neck lymphomas revealed as homogenous masses affecting regional anatomic areas. Osseous lymphomas were imaged as a soft tissue mass with cortical destruction. Intrathoracic involvement was usually manifested as nodular lesions or mass with consolidation and pleural effusion. CNS lymphomas were revealed as an enhancing brain mass. Primary testicular lymphoma was seen on US as a focal area of hypoechogenicity.Conclusion: The imaging findings of extranodal involvement of NHL are greatly diverse and may mimic a variety of neoplastic and non-neoplastic conditions, depending upon the site of involvement. The radiologist should include NHL in the differential diagnosis of a lesion even in sites of unusual abnormal lymphomatous involvement.

C-698 Imaging spectrum of motorcycle injuries from head to toe S.E. Smith, J.P. Mazzie, M.D. Setton, S. Mirvis; Baltimore, MD/US (sesmd@yahoo.com)

Learning Objectives: The purpose of this educational exhibit is to present a variety of motorcycle-related injuries, that we have encountered over the past 5 years, from head to toe.Background: Maryland’s R.Adam Cowley Shock Trauma center is one of the larg-est level-one trauma centers in the USA, which sees a vast array of trauma victims from the entire eastern coast, the majority being those involved in motorcycle col-lisions. According to a recent national study (Am J Epid 2007) from the National Center for Injury Prevention and Control, CDC, fatal traffic injury rates are highest for motorcyclists, pedestrians and bicyclists. Motorcycle injuries also constitute the highest number of nonfatal traffic injuries.Imaging Findings: Examples of cases to be presented include devastating trau-matic brain and spinal injuries as well as complicated fracture-dislocations, utilizing a variety of imaging modalities from plain radiographs, including Lodox images (an innovative new low-dose full body imaging device currently at our institution) to CT and MRI. Additional cases to be presented include traumatic vascular, intra-abdominal and deforming/disfiguring, degloving injuries. The mechanism of these injuries will also be reviewed as will the current recommendations on imaging algorithms of trauma patients.Conclusion: With motorcycle injuries constituting the most fatal and nonfatal injuries in the USA, awareness of these types of injuries and their appearances on multiple different modalities as shown in this exhibit will help the radiologist to identify important findings and to suggest further ancillary studies.

C-699 Orthopaedic metallic implants: A pictorial review A. Kraus, E. Buschmann, D.P. Deva; Stoke-on-Trent/UK (boletus@gmx.net)

Learning Objectives: To give an overview of the different metallic implants en-countered in orthopaedic radiology as well as their function and appearance on X-ray and to highlight possible problems and complications.Background: Orthopaedic metallic implants are often encountered on X-rays. Although they usually cannot be overlooked, their exact name, their purpose and possible complications are not necessarily obvious.Imaging Findings: We give a short history of orthopaedic metallic implants from Kuntscher’s pin and Charnley’s total hip replacement to modern osteosynthesis materials. We present different implants with their radiological appearance, their function and potential complications, which a radiologist should know about.Conclusion: Metallic implants are frequently seen on musculo-skeletal X-rays. Therefore a radiologist should know the different types as well as their function and potential complications, which we have presented here.

C-700 Minimising radiation dose in MR arthrography L. Manavalan; Belfast/UK (lathanambi@yahoo.com)

Purpose: The aim of this study was to reduce radiation dose by optimising fluoro-scopic technique for MR Arthrograms (MRA).Methods and Materials: We performed a retrospective review of fluoroscopic dose data of shoulder and hip MRA done over a year. It showed that approximately one third of the Dose Area Product (DAP) reading originated from Digital Radiology (DR) exposures. It was decided that fluoroscopy image store adequately demonstrated intra-articular access; hence DR exposures were abandoned and the use of optimum fluoroscopy technique was reinforced among the departmental staff. The dose data was again reviewed for a one year period to assess any change.Results: The first phase of the study included 42 shoulder and 23 hip MRA. The mean DAP for shoulder MRA was 24 μGym2, mean fluoroscopy time (FT) was 44 seconds, and on an average 1.5 digital radiology (DR) exposures were performed. For hip MRA, the mean DAP was 58 μGym2, mean FT was 36 seconds and on an average 1.8 DR exposures were performed. The second phase of the study included 25 hip and 56 shoulder MRA. For shoulder MRA, the mean DAP was 11.2 μGym2 and FT was 49 seconds. For hip MRA, the mean DAP was 14.7 μGym2 and FT was 46 seconds. No digital exposures were performed.Conclusion: Significant dose reduction (53% for shoulder MRA and 75% for hip MRA) was achieved by the use of fluoroscopic image store.

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C-701 Estimation of bone mineral density and bone strength-muscle strength relationship in elderly postmenopausal hemodialysis women using peripheral quantitative computed tomography (pQCT) A. Balanika, T. Spyridopoulos, C. Baltas, O. Papakonstantinoy, I. Mouchtouri, A. Kelekis, G. Skarantavos, D. Vlachakos, A. Gouliamos; Athens/GR (mpaltas@hotmail.com)

Purpose: The aim of this study was the evaluation of bone mineral density and relation between bone strength and muscle force in elderly postmenopausal he-modialysis females by peripheral Quantitative Computed Tomography (pQCT) as a means of predicting fracture occurrence in these patients.Methods and Materials: Trabecular and cortical bone mineral density (TBD and CBD) strength-strain index (SSI) cortical area (CA), bone cross-sectional area (BCA), muscle cross-sectional area (MCA), fat cross-sectional area (FCA) and BCA/MCA ratio were estimated in 12 elderly postmenopausal hemodialysis women (mean age 72.5) by pQCT at the tibia of the no dominant lower leg.Results: Compared with 18 healthy women, matched for age and body mass index (BMI), cortical and trabecular bone densities, strength-strain index, cortical area, bone cross-sectional area and BCA/MCA ratio were significantly reduced in postmenopausal hemodialysis females. There is no significant difference in muscle cross-sectional area although fat cross-sectional area was significantly increased in postmenopausal hemodialysis patients.Conclusion: Elderly postmenopausal hemodialysis women showed low quality (low TBD, CBD) and fragile bones (low BCA, SSI). The reduced SSI and BCA/MCA ratio indicate a musculoskeletal imbalance and increase the appendicular fracture risk in these patients.

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C-702 Cerebral CT venography using 64-slice MDCT: A new door is open H. Patel, M. Doctor, A.J. Shah, G. Tomar, M. Patel; Ahmedabad/IN (hemantmri@gmail.com)

Learning Objectives: To provide anatomy of cerebral veins and dural venous sinuses using MDCT. To gain familiarity with postprocessing for intracranial venous system. To demonstrate CT venography appearances of cortical and dural venous sinus thrombosis. To evaluate advantages and limitations in comparison with MR venography.Background: Dural venous sinus thrombosis has always remained an underdiag-nosed clinical condition. MR venography has remained the main tool for evaluation of cerebral venous pathology. However in certain cases of nondominent transverse sinus or sluggish flow, it is difficult to do precise diagnosis with MR venography. CT venography using MDCT with isotropic resolution can demonstrate dural sinus and cortical venous thrombosis very efficiently. In this exhibit, we will describe anatomy and variants of cerebral veins, techniques of CT venography - MIP-mathed mask bone elimination (MMBE) - SSD, and the advantages of CT venography over MR venography. Between January 2007 and August 2007, 36 patients suspected with dural venous thrombosis underwent CT venography. Clinical cases, variants, mimicks and MRV correlation are described and illustrated.Imaging Findings: CT venography demonstrated all dural sinuses. In cases of venous thrombosis, major imaging findings were: 1. filling defect 2. empty delta sign 3. collateral venous drainage. All images were artifacts free as a result of fast scan-ning with 64 slice CT scanner. It was possible to demonstrate thrombosis in cases where slow flow status and nondominance of transverse sinuses were present.Conclusion: Cerebral CT venography is a fast and reliable method for evaluation of cortical and dural venous sinus thrombosis. CT venography with 64 slice MDCT, using proper technical parameters and postprocessing techniques, is a viable al-ternative to MR venography and DSA. In certain situations cerebral CT venography overscores MR venography.

C-703 Sinus vein thrombosis: Review and need-to-know principles M. Martinez Galdamez, J. Hernanz Padial, G. Saucedo Diaz, B. Brea Alvarez, A. Vega Astudillo, P. Ruiz García; Madrid/ES (mariomgaldamez@hotmail.com)

Learning Objectives: To demonstrate the role of the multidetector CT, MRI and cerebral arteriography in the diagnosis and management of sinus vein thrombosis. To pictorially review the main imaging features describing and comparing with the literature.Background: Sinus vein thrombosis is an infrequent entity with a nonspecific presenta-tion and numerous predisposing causes. Multidetector CT and MRI are two necessary non invasive techniques for a complete and good evaluation with high correlation with cerebral arteriography. An accurate evaluation and knowledge of the differential diag-nosis by the radiologist can identify them easily. In this exhibit, we review the literature and present several cases of sinus vein thrombosis from our database.Imaging Findings: We have reviewed image studies performed in our hospital during the last five years. We describe the main imaging findings of sinus vein thrombosis on unenhanced CT multidetector, intravenous contrast-enhanced CT multidetector CT, MRI sequences and cerebral arteriography. Multidetector CT and MRI are two complementary non-invasive excellent modalities for the diagnosis. The high resolution of the CT multidetector and the possibility of multiplanar re-constructions allow an excellent identification.Conclusion: This exhibit provides an overview of the sinus vein thrombosis. Multidetector CT has an important role in the emergency room for its availability, speed, high resolution and the possibility of multiplanar reconstructions having good correlation with MRI and arteriography.

C-704 Diffusion, tensor and spectroscopic MR imaging manfiestations of intracranial tuberculous abscesses R.M.S.V. Vadapalli1, R. Hn2, J. Akkaraju3, G. Sreeram2, P. Pradhan2, M. Bhandari2, S. Prasanna2; 1Colombo/LK, 2Bangalore/IN, 3Hyderabad/IN (rammohanvsv@yahoo.com)

Learning Objectives: 1. To understand the morphological characteristics of intracranial tuberculous abscesses and to differentiate tuberculomas, NCC, other bacterial abscesses and metastases, Necrotic GBM. 2. To highlight diffusion im-aging and MR spectroscopy findings of abscesses in general and tuberculous abscesses in specific.

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Background: Abscesses result from varied etiologies and pathogens. Tuberculous, pyogenic and parasitic abscesses constitute the important categories. MR spectros-copy further interrogates these lesions adding characterization info to differentiate them from necrotic neoplasms by a normal choline creatine ratio, aminoacid and lactate and lipid peaks on MRS. The importance of acetate, succinate peaks will be discussed. The DWI spectrum of findings in tuberculous abscesses will be discussed with ADC value comparision.Imaging Findings: Infective granulomatous abscesses pose day to day diag-nostic imaging challenges with varied appearances. Comprehensive protocol for an intracranial abscess includes diffusion and tensor imaging and ADC, T1 post contrast, MR spectroscopy to highlight lipid lactate, aminoacid peaks (succinate and acetate) and normal or low choline/creatine ratio. Tensor imaging further adds characterization indices like FA value Tumor vs abscess and necrotic neoplasm dilemmas will be illustrated with examples by highlighting DWI ADC and DTI and spectroscopy findings. Importance of acetate, succinate and pyruvate peaks will be discussed. The DWI spectrum of findings in tuberculous abscesses will be dis-cussed with ADC value comparision metastases; GBM can be thus differentiated with opimal diagnostic yield.Conclusion: DWI with ADC, MR spectroscopy, DTI indices are very useful adjunct tools in addition to the conventional pre and post contrast brain imaging for charac-terization of intracranial typical and atypical tuberculous abscesses.

C-705 Cortical laminar necrosis: What, when and why C. Andreu, I. Hernandez, M. Manzano, B. Lopez-Botet, L. Fernandez Fresno, R. Manzanares; Madrid/ES (carlotaandreuarasa@yahoo.com)

Learning Objectives: To review the usual and unusual pathologic processes that present cortical laminar necrosis as an imaging finding. To explain these findings from a histological point of view.Background: Laminar cortical necrosis (LCN), neuropathologically characterized by delayed selective neuronal necrosis of the cerebral cortex, is a well-known consequence of encephalopathy, hypoglycaemic encephalopathy, cerebrovascular diseases, or status epilepticus. LCN has been reported in Marchiafava-Bignami encephalopathy as a gliosis-necrosis of the third layer of the cortex, as well as it has been related to cluster breathing after a subaracnoid hemorrage, and also in patients with hepatic encephalopathy, translating pseudolaminar spongy degenera-tion. LCN has been described in survivors of intracranial germ cell tumors, after radiation, and in kidney trasplant patients treated with tacrolimus.Imaging Findings: MRI studies have reported that cortical laminar necrosis is visualized as high-intensity areas on T1-weighted image and FLAIR, not due to hemorragic transformation (normal T2*); the T2-weighted image shows low or high intensity, and diffusion-weighted MRI shows high intensity of the cortical area. LCN is a pannecrosis of cerebral cortex (neurones, glia cells and vessels), due to a high vulnerability of the cortex to oxygen and glucose deplection. Even though it is an anatomopathologiccal concept, it has an MRI transcription.Conclusion: This poster presents the vast spectrum of processes, checking over each, both usual and unusual ones, that show laminar cortical necrosis as one of their imaging findings and explains their pathological correlation.

C-706 Hyperdense hemorrhage, hematoma, and thrombus on plain CT: signs for critical pathology H. Odani, J. Matsumoto, S. Nakaji, Y. Minowa, Y. Nakajima; Kawasaki/JP (hirokoo@maple.ocn.ne.jp)

Learning Objectives: 1) To learn the significance and importance of hyperdense hemorrhage, hematoma, and thrombus on plain CT, which can indicate acute hemorrhagic or ischemic disorders (including infarction). 2) To discuss the potential pitfalls in diagnosis with thsese findings.Background: Acute hemorrhagic diseases and ischemic disorders (including infarction) are often nonspecific on clinical and imaging findings. Hyperdense hem-orrhage, hematoma and thrombus on plain CT can be key findings in diagnosing these diseases, but these features are often very difficult to identify on contrast-enhanced CT or plain CT, unless a careful observation is made.Imaging Findings: The exhibit consists of the following: 1) Density of hemorrhage, hematoma and thrombus on plain CT, 2) differential diagnosis for hematoma seen as a high-attenuating area on plain CT, 3) significance of plain CT for diseases with acute hemorrhage and thrombus, 4) high-attenuating areas due to hemorrhage, hematoma, and thrombus in various diseases including hyperacute cerebral infarc-tion, cerebral sinus thrombosis, pulmonary embolism, alveolar hemorrhage, aortic dissection, impending rupture of the aortic aneurysm, gastrointestinal bleeding, bowel ischemia from various causes, ovarian hemorrhage, rupture of ectopic pregnancy, ovarian torsion, and trauma.

Conclusion: Because hyperdense hemorrhage, hematoma, and thrombus can be key findings in hemorrhagic and ischemic diseases, radiologists should be aware of the significance of these findings. Diagnosis of these critical diseases is likely to be easier and more accurate if an initial plain CT scan is performed, even in cases in which a contrast-enhanced CT scan is required.

C-707 Pericerebral fluid collections in children: Differential diagnosis using ultrasonography, computed tomography and magnetic resonance imaging J.E. Vazquez, N. Mayolas, I. Barber, S. Boronat, M. Roig, G. Enriquez; Barcelona/ES (evazquezjimenez@gmail.com)

Learning Objectives: Our aim is to stablish adequate radiological differential diagnosis between the diverse extracerebral fluid collections in children and to rule out subdural hematoma secondary to non-accidental trauma.Background: Extracerebral fluid collections in children are a common finding in daily practice and include benign enlargement of subarachnoid spaces (BESS), subdural hygromas, subdural or epidural hematomas, and subdural or epidural empyemas. These fluid collections may have different pathophysiologycal mecha-nisms. The modern imaging advances used in US, CT and MR may help to improve differential diagnosis with relevant implications in therapy and prognosis.Procedure Details: We retrospectively reviewed 646 pediatric patients with peric-erebral fluid collections, who were seen in a big tertiary children’s hospital over the last 10 years. Diagnosis was made based on the clinical and imaging findings by Doppler US, CT and MR, including diffusion imaging (DI). BESS was found in 36.07%, epidural hematomas in 30.19%, subdural hematomas or hygromas in 30.65% and empyemas in 3.09%. Representative cases are presented with emphasis on the most relevant imaging signs on US, CT and MR.Conclusion: Colour Doppler helps to identify the cortical veins within the sub-arachnoid space in infants, being particularly useful to differentiate between BESS and subdural collections. Nevertheless, subdural hematomas can appear in asymptomatic children with BESS, due to stretching of the bridging veins. MRI and diffusion imaging has been found particularly valuable for detecting small subdural collections, such as empyemas; the diverse chronology with retinal hemorrhage assess non-accidental trauma.

C-708 Brain poisoning: Accidental and intentional exposure (a review) A. Domingo1, M. Andreu1, J. Vives1, A. Camins2, E. Salvadó1, A. Ramos1, A. Saurí1; 1Tarragona/ES, 2Barcelona/ES (angelsdc@yahoo.com)

Learning Objectives: 1. To review some of the most common types of brain poisoning such as alcohol (acute and chronic toxicity), methanol, CO, radiation and chemotherapy, recreational drugs, myelinolysis, hepatocerebral degeneration, and heavy metals. 2. To describe some characteristic imaging features that may be helpful in identifying the underlying etiology.Background: Some recreational drugs and other types of brain poisoning, such as environmental and industrial chemicals (methanol, carbon monoxide, etc.), therapeutic drugs (chemotherapy, immunosuppressive agents) or metals (lead, mercury, etc.) can cause acute or permanent brain damage, due to intentional or accidental exposure. At the clinical onset, the causative agent is frequently unknown and neuroimaging may represent a helpful tool.Imaging Findings: Neuroimaging plays a major role in the diagnoses of brain poisoning. The white matter is often diffusely and symmetrically involved, and also frequently the basal ganglia and brain stem. MRI shows T2 prolongation of these lesions although these findings are usually non-specific. However, there are some characteristic imaging features that may be useful to identify the underlying etiology and to assess the clinical management. The use of diffusion-weighted and perfusion imaging can help to understand the physiopathology of such entities.Conclusion: It is usually difficult to attribute a specific clinical syndrome to a particular brain toxin. The causative agent is frequently unknown at the clinical outcome. Moreover, patients frequently show polydrug abuse, which makes diag-noses even more difficult. MRI and use of DW and perfusion imaging can help to identify the underlying etiology.

C-709 Controversies of the MR based diffusion-perfusion mismatch concept for selecting acute stroke patients for thrombolytic therapy A. Rovira1, A. Rovira2, J. Munuera1, A. Carvajal2, G. Garrido1, A. León1, L. Frascheri1, C. Auger1; 1Barcelona/ES, 2Sabadell/ES (alex.rovira@idi-cat.org)

Learning Objectives: To present a critical overview of the use of diffusion-perfusion mismatch (DPM) concept for selecting patients for thrombolytic therapy. To suggest novel approaches to identify salvageable ischemic tissue in these patients.

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Background: In clinical decision making and clinical trial enrollment, perfusion-weighted imaging (PWI) sequences are considered mandatory for proper selection of ischemic stroke patients who may benefit from thrombolytic therapy. However, PWI is a complex, time consuming, and not well standardized technique, which limits the use of MRI for this purpose.Procedure Details: The advantages and drawbacks of the DPM concept are analyzed on the basis of a literature review and on our experience with multimodal MR imaging in more than 250 patients who were candidates for thrombolytic therapy. Patient selection based on the presence of diffusion-weighted imaging (DWI)-MR angiography mismatch has shown very high sensitivity for detecting patients with a DPM, simply by combined analysis of the extension of the DW signal abnormality and the presence and location of the relevant arterial occlusion by MR angiography.Conclusion: Prior to the use of multimodal MRI for selecting acute stroke patients for thrombolytic therapy, the drawbacks of the DPM concept must be known. Ef-forts should be made to design a simplified, well-standardized method to select patients for this purpose with MRI as this will probably lead to an increase in the number of patients treated.

C-710 Neurosurgical application of diffusion tensor imaging with 3D fiber tractography S.S. Gupta, Z.M. Patel, B.K. Misra; Mumbai/IN (drsantoshg@rediffmail.com)

Learning Objectives: To provide a pictorial review of Diffusion Tensor Imaging (DTI) with 3D fiber tractography so as to: (1) delineate the anatomy of white mat-ter tracts pre-operatively in intra-axial cerebral lesions and to depict the relation of these lesions to the eloquent cortex /white matter tract; (2) as an aid in planning surgical approach; and (3) for post-surgical evaluation of the tracts.Background: DTI is a rapidly evolving noninvasive MR technique which is widely being used for imaging the anatomy and has been proposed as a technique suitable for neurosurgical planning, which we have tried to evaluate in a series of patients with intra-axial focal mass lesions.Imaging Findings: We evaluated 20 patients with intra-axial cerebral focal mass lesions, all of whom were operated, along with post-operative MR in 4 patients for evaluation of various tracts. The sequences obtained were axial T2, 3D-SPGR and DTI (in 25 directions). Images were post processed using the GE research software devised for tractography. The maps obtained were: (1) fractional-anisotropy maps, (2) directionally encoded color maps and (3) 3D fiber tractography maps. The information provided on all the 3 maps were used in conjunction and the results were categorized as displaced/uninvolved tracts and involved/infiltrated tracts. The DTI information was correlated with pre and post-operative neurological findings with good results.Conclusion: DTI helps to establish relationship between white matter tracts and focal mass lesions, thereby improving the accuracy of surgical risk assessments, preoperatively, and allowing safe radical excision as well as for post-operative follow-up.

C-711 Diffusion tensor imaging and T2 relaxometry in medial temporal lobe epilepsy on 3 T MRI R.K. Rima Kumari, B. Guglani, R. Gupta, N. Gupta; Delhi/IN (rimarohit@gmail.com)

Learning Objectives: To illustrate the utility of T2 relaxometry and diffusion tensor imaging versus visual assessment in the evaluation of mesial temporal sclerosis on 3 T MRI. To describe the comparative results of these methods based on a study of 25 patients.Background: Quantitative apparent diffusion coefficients and fractional anisotropy have emerged from being primarily research tools to methods enabling valuable clinical applications. Increased T2 relaxation times in the ipsilateral hippocampus are present in patients with hippocampal sclerosis. This study was undertaken to assess the changes of T2 relaxation times and diffusion indices (MD, FA values) of hippo-campal formation (HF) in patients with medial temporal lobe epilepsy (MTLE).Imaging Findings: Fifteen patients with MTLE and 10 healthy controls were evalu-ated on a 3-T General Electric Signa HDX unit using conventional MR imaging, 3D SPGR sequence, coronal T2 maps and 3D EPI sequence for DTI. T2 relaxation times were measured in the hippocampus. Mean diffusivity (MD) and fractional anisotropy (FA) maps were constructed and the symmetrical voxel sampling regions of the anterior HF were calculated. The MD and FA values were compared in epileptic patients and normal controls and were correlated with subjective evaluation.Conclusion: DTI and T2 relaxometry help in the diagnosis of mesial temporal sclerosis with bilateral symmetrical involvement and in borderline or doubtful cases. This indicates the high precision of T2 relaxometry and DTI at 3 T and may serve as a useful tool for preoperative assessment of seizure focus in patients with MTLE.

C-712 The many MR imaging faces of glioblastoma multiforme: A pictorial assay of typical and atypical features R.M.S.V. Vadapalli1, S. Perera1, F. Perera1, R. Hn2, C. Kishore2, S.K.V. Bommana2, R. Lakshmi2; 1Colombo/LK, 2Bangalore/IN (rammohanvsv@yahoo.com)

Learning Objectives: To Illustrate the typical MR morphological features of GBM. To highlight the atypical MR features glioblastoma and elucidate their importance and potential mimics. To show some eye opening cases and discuss the differential diagnosis of GBM.Background: GBM is often termed as a terminator among all primary brain neoplasms as it carries a very poor prognosis and surgical outcomes. Hence it is important to overview its many imaging facets on MRI and improve early diagnosis. In this exhibit, typical features of GBM on DWI, perfusion and MRS are illustrated followed by its atypical features.Imaging Findings: The classical features of callosal and hemispheric glioblastomas on DWI, ADC, DTI perfusion and MR spectroscopy will be discussed with illustra-tive examples. The atypical and overlap features are classified in these following categories: A) GBM mimicking an abscess B) GBM mimicking a granuloma C) GBM mimicking a lymphoma D) GBM minicking intracerebral haemorrhage E) GBM mimicking a metastasis F) GBM mimicking a tumefactive demyelination.Conclusion: Present day comprehensive tumor protocol including diffusion and perfusion imaging and tractography and MR spectroscopy features adds diagnostic characterization information that can be a problem solving diagnostic tool in GBM early diagnosis and follow-up.

C-713 Not so rare: Imaging findings of leptomeningeal carcinomatosis M. Martinez Galdamez, G. Saucedo Diaz, B. Brea Alvarez, S. Cornide Santos, C. García Roch, L. Nombela Cano; Madrid/ES (mariomgaldamez@hotmail.com)

Learning Objectives: To illustrate characteristic imaging findings of leptomeningeal carcinomatosis. To review and become familiar with the differential diagnosis. To demonstrate the role of the Multidetector CT and MRI in the diagnosis and man-agement of the leptomeningeal carcinomatosis.Background: Leptomeningeal carcinomatosis is a serious and infrequent com-plication of cancer that carries substantial rates of morbidity and mortality, which is increasing during the last years. Imaging plays a key role in the diagnosis and management of leptomeningeal metastases because the cytology of CSF is often falsely negative. In this exhibit, we review the literature and present several cases of leptomeningeal carcinomatosis from our database.Procedure Details: A retrospective review from our hospital was performed in patients with various causes of leptomeningeal carcinomatosis describing and comparing the main imaging findings. Intravenous contrast-enhanced CT and es-pecially MRI sequences and gadolinium enhancement on T1W allow the radiologist to reach the specific diagnosis in a majority of cases. MRI is the imaging study of choice and slightly more sensitive than CT.Conclusion: This exhibit provides an overview of the leptomenigeal carcinomatosis which can help the radiologist to better recognize this entity. CT and especially MRI are two complementary non-invasive excellent modalities for this purpose.

C-714 Neuroradiological findings in epilepsy patients with hemispheric syndromes N. Bargalló, A. Radosevic, M. Carreño, A. Donaire, J. Setoain, M. Squarzia, S. Capurro, F. Calaf, N. Sigritz; Barcelona/ES (bargallo@clinic.ub.es)

Learning Objectives: To illustrate the neuroradiological findings observed in epileptic patients associated to hemispheric syndromes.Background: There are several diseases that are associated to refractory epilepsy characterized for continuous focal seizures originated in the pathological hemisphere. These diseases are: Rassmussen syndrome; focal sclerodermia with neurological involvement; Perry Romberg syndrome; neurocutaneous syndromes such as Stuger-Weber syndrome and tuberous sclerosis; congenital malforma-tion as hemimegancephaly and migration disorders and residual lesions related to vascular or infection injuries. We review the neuroimaging features of each disease and the usefulness of different neuroimaging technique in the manage-ment of these patients.Imaging Findings: Similar neuroradiological findings are observed in some of these diseases such as Rassmussen Sd, Perry Rombert Sd or focal esclerodermia. Differential diagnosis has to be done with congenital infectious or previous vascular injuries. Other diseases such hemimegancephaly or Stuger Weber have very typical findings. Functional studies such fMRI or SISCOM can help to evaluate eloquent areas involved and to delimitate the epileptogenic zone.

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Conclusion: Neuroradiological studies are an important tool for identify underlying structural causes in epileptic patients with hemispherical syndromes. Neurofunc-tional imaging has an essential role, both in surgery planning and in identification of the functional regions involved.

C-715 Central nervous system tuberculosis: Spectrum of imaging findings at 3 Tesla MRI B. Guglani, R. Kumari, N. Gupta, P. Sarin; New Delhi/IN (bhuvnesh1@gmail.com)

Learning Objectives: To describe and illustrate the spectrum of findings in central nervous system tuberculosis at 3 Tesla MRI.Background: A retrospective study of MR findings in 41 patients (including 3 AIDS patients) with proven CNS tuberculosis was carried out.Imaging Findings: The following abnormalities were seen on MRI brain scans - solitary or multiple brain tuberculomas, basal exudative leptomeningitis, focal cerebritis, pachymeningitis, hydrocephalus, vasculitis and acute infarcts, ventricu-litis and choroid plexitis. The basal exudative leptomeningitis and hypointensity on T2W with conglomerate ring like enhancement of focal tuberculous lesions were most commonly observed patterns of intracranial tuberculosis. The majority of tuberculomas (~90% cases) appeared predominantly hypointense or isointense on T2W images with presence of nodular and ring pattern of enhancement. A lipid resonance at 0.9-1.3 ppm was noted in all of 11 intracranial tuberculomas evaluated by in vivo proton MR spectroscopy. T1-weighted magnetization transfer (MT) imaging was useful in characterization of the tuberculomas as well as of tuberculous meningitis. The spinal abnormalities included arachnoiditis, myelitis, intramedullary tuberculoma, and epidural abscess and cord compression associ-ated with spondylitis. The common abnormalities in spinal arachnoiditis were CSF loculations, enhancement of meninges, nerve roots or cord, clumping of cauda equina nerve roots, cord edema and cord cavitation.Conclusion: MRI with gadolinium enhancement plays an important role in dem-onstrating the extent and patterns of CNS tuberculosis. Proton MR spectroscopy and T1W magnetization transfer imaging are useful in better lesion characteriza-tion and discrimination of intracranial tuberculous lesions from other inflammatory granulomas and mitotic pathology.

C-716 Imaging gallery of diseases involving the bilateral thalamus T.-C. Wu, Y.-K. Tsui, T.-C. Wu, T.-Y. Chen, W.-S. Tzeng; Tainan/CN (porthoswu@yahoo.com.tw)

Learning Objectives: The distribution or involvement of specific anatomic sites by symmetric lesions can point to certain disease group and even imply the diagnosis of the disease. The purpose of this presentation is to investigate the imaging findings and to discuss the possible differential diagnosis of the diseases involving bilateral thalamus in different categories.Background: The thalamus acts as a “bridge” for the various pathways in the mo-tor, sensory and consciousness systems. Clinical presentation of thalamic lesions might be vague and confusing. In such circumstance, imaging studies such as CT and MR imaging could play an important role in the localization of the lesion and diagnosis of the disease.Imaging Findings: Four categories, including vascular (embolic events via the artery of Percheron, hypoxic-ischemic encephalopathy, venous thrombosis, pseudotumor cerebri secondary to dural AV fistua), neoplasm (gliomatosis cerebri, bilateral thalamic astrocytoma, neurofibromatosis type I, intraventricular lymphoma), metabolic/toxic (Wilson disease, Wernicke’s encephalopathy) and infection/inflammation (Japanese encephalitis, acute necrotizing encephalitis, posterior reversible encephalopathy syndrome) are reviewed and the differential diagnosis discussed.Conclusion: Being familiar with imaging findings and the clinical presentation of diseases involving the bilateral thalamus would be helpful in the differential diagnosis.

C-717 Osmotic demyelination: A pictorial essay of MRI findings S.K.V. Bommana1, U.D. Patil1, R.M.S.V. Vadapalli2, B.Y.T. Arya1, R.H.N. Hanasoge1; 1Bangalore/IN, 2Colombo/LK (bommanasubhash@yahoo.com)

Learning Objectives: 1. To understand the etiology of osmotic demyelination. 2. To discuss the special imaging features of osmotic demyelination on MRI. 3. To review the classical MRI protocols in a case of osmotic demyelination.Background: Osmotic demyelination (or myelinolysis) occurs in cases of severe electrolyte imbalance in some clinical settings. The findings may be mistaken for other causes of aquired demyelinations. However, awareness of the classical im-

aging findings of this condition helps one to arrive at an accurate diagnosis. This exhibit focuses on the etiology and characteristic imaging features and discusses the classical MRI protocols in such cases.Imaging Findings: 1. The distribution of lesions in osmotic demyelination and their clinical settings will be discussed. 2. Their spectrum of MRI imaging features will be highlighted.Conclusion: At the end, the reader will be able to understand the etiology, distribu-tion and imaging findings of osmotic demyelination and the classical MRI protocols to be followed in these cases.

C-718 MR imaging of radiation therapy- and chemotherapy-induced injury of the brain L. Pruzincova, V. Belan, J. Moczova, E. Boljesikova, M. Chorvat, B. Rychly, I. Makaiova, J. Steno; Bratislava/SK (lubicap7@gmail.com)

Learning Objectives: To describe magnetic resonance imaging spectrum of late-delayed, therapy-induced injuries of the brain (LDTI), with particular emphasis on radiation necrosis. To demonstrate the value of perfusion MRI, diffusion-weighted (DW) imaging and proton MR spectroscopy included in the MR protocol.Background: The incidence of LDTI is 5-37% and may develop from several months to years after therapy. Differentiation from tumor recurrence may be difficult with conventional MR imaging, since both have a similar radiologic appearance. At our institution, a complex examination with perfusion MRI, DW imaging and MR spectroscopy is used. Presented images were selected from 127 patients examined between 2004 and 2007. Diagnosis was established by histology or PET. The results, advantages and the limits of this techniques are described and illustrated.Imaging Findings: The typical appearance of tumor recurrence and LDTI is an expansive enhancing mass surrounded by edema. LDTI should be suspected if perfusion MR demonstrates reduced blood volume in contrast to neoplastic lesions and MR spectroscopy shows low ratios of Cho/Cr and Cho/NAA. Also, a lipid peak is detected and decreasing or unchanging cholin is observed in follow-up studies. In our study on DW imaging, ring enhancing lesions of radiation necrosis have very low ADC values in the central nonenhancing part compared with such types of lesions consistent with TU recurrence.Conclusion: Beyond morphologic information provided by conventional MR imaging, DW imaging, perfusion MRI and MR spectroscopy can offer additional information for the differentiation of neoplastic and nonneoplastic brain lesions after treatment.

C-719 Meningeal enhancement: Causes and radiological findings M. Navallas, A. Martãnez de Aragãn, L. Ibaãez, P. Dãez, R. Cano, P. Orenes; Madrid/ES (mnavallas@gmail.com)

Learning Objectives: 1. To describe the meningeal normal appearance on MRI as well as the imaging findings in both patterns of contrast enhancement: lepto-meningeal and pachymeningeal. 2. To review the different pathologic processes that produce each pattern of meningeal enhacement.Background: There are many diseases that produce pachymeningeal enhance-ment (leak of CSF, hypertrophic idiopatic pachymeningitis, intracranial hypotension, infections, inflammatory diseases, metastases, SAH) and leptomeningeal (CVA, infections, inflammatory diseases, metastases).Imaging Findings: Both types of meningeal pathologies can be easily distinguished by the pattern of contrast enhancement on MRI. Leptomeningeal enhancement extends into the subarachnoid spaces of the sulci and cisterns. Pachymeningeal enhancement is well seen in the dural reflections of the falx cerebri, tentorium cer-ebelli, falx cerebelli and against the cortical bone of the inner table of the skull. It is thick and can be lineal or nodular and does not involve the sulci or the cisterns.Conclusion: A detailed study of the pattern of contrast enhancement with MRI and gadolinium-based contrast agents enables a more precise etiologic diagnosis of the different pathologies that involve the meninges.

C-720 A guide to diagnosis of acute hydrocephalus in children and importance of radiological imaging in assessment following surgical treatment R.C. Murphy, O. Kirmi, G. Quaghebeur; Oxford/UK

Learning Objectives: A pathway for the diagnosis of acute hydrocephalus, high-lighting clinical and radiological findings. Pitfalls are addressed. To assess role of imaging following treatment for evaluation of complications.Background: Untreated hydrocephalus can result in death. Early diagnosis is essential.

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Imaging Findings: Increasing head circumference, widened sutures, tense fontanelle (unfused sutures), headache, vomiting, visual disturbance and papilloe-dema raise the suspicion of hydrocephalus. Before fusion of sutures, transcranial ultrasound is first choice, assessing for ventriculomegaly, haemorrhage or masses. Following closure of sutures, CT is first line investigation. Ventriculomegaly, rounding of the 3rd ventricle, sulcal effacement, periventricular low attenuation, narrowing of the ventricular angle, widening of the frontal horn radius indicate hydrocephalus. Causes and complications can be assessed by imaging. Pitfalls include differen-tiation from white matter atrophy. The most reliable signs for this are rounding of the 3rd ventricle, increase in anterior and posterior recesses and commensurate dilatation of the temporal horns with the bodies of the lateral ventricles. In children with temporal lobe atrophy, temporal horn enlargement is not reliable. Periventricu-lar oedema is not seen in young children due to masking by high cerebral water content. Post treatment imaging assesses shunt position, ventricular size, subdural haematoma and ventriculitis. MR is the study of choice for third ventriculostomies. CT is the standard for shunt malfunction. Contrast enhancement is essential for assessment of ventriculitis.Conclusion: Acute hydrocephalus is difficult to diagnose. Clinical and radiological findings assess the rapidity of onset, severity and cause, allowing for prompt referral and post-operative assessment.

C-721 Surface anatomy of inferior parietal lobule in high resolution three-dimensional MRI I. Kiriyama, H. Miki, Y. Hiratsuka, K. Kikuchi, T. Mochizuki; Toon city/JP (ikukosan@m.ehime-u.ac.jp)

Learning Objectives: To know optimal sequences and display methods of high resolution (HR) 3D-MRI of brain. To learn topography of inferior parietal lobule on HR volume rendering images and anatomic specimens.Background: In recent studies by functional MRI, it has been revealed that the inferior parietal lobule supports an extensive range of sensory and cognitive func-tions. The surface anatomy of the brain is strongly correlated to specific neurologic function, and it is important to understand anatomy of the inferior parietal lobule. However, it is extremely difficult to identify sulci or gyri of parietal lobe in two-dimensional trans-axial images. 3D images are essential to understand normal structures of inferior parietal lobule.Procedure Details: Forty healthy volunteers were examined with a 1.5 T MRI. All volunteers had informed consent. MRI was performed by 3D-SPGR with HR matrix, and volume rendering (VR) images of brain surface were generated. Clas-sification of structural pattern of inferior parietal lobule according to the published literature of Naidich et al. (1995) was performed with VR images and MPR images on a monitor. In addition, 20 human specimens were classified visually. Variability of the gyral pattern of the inferior parietal lobule in MR study was similar to those in past reports and those in anatomic specimens.Conclusion: Gyri and sulci of the inferior parietal lobule were clearly depicted on VR image with appropriate display method. The individual components of the inferior parietal lobule show variable morphology and right-left asymmetry.

C-722 Persistent trigeminal artery: Imaging by CTA and MRA with depiction of additional anatomical variations in intracerebral arterial vasculature A. Ghandi, H.L.J. Tanghe, D.W.J. Dippel, A. van der Lugt; Rotterdam/NL (aghandi78@gmail.com)

Learning Objectives: 1. To illustrate a rare pathway variant of the persistent trigeminal artery (PTA) observed with CTA. 2. To discuss anatomic variations in intracerebral vasculature related to the presence of the PTA.Background: 1. Introduction. 2. Anatomy of the PTA, description of the most com-mon pathways. 3. Association of anatomic variations in intracerebral vasculature with the PTA.Imaging Findings: 1. Most commonly used imaging methods are discussed. 2. CTA images of the PTA and the intracerebral vessel variations are displayed.Conclusion: The major teaching point of this exhibit is: knowledge of the varying courses of the PTA and its associations with other intracerebral anatomic vessel variations.

C-723 Neurological emergencies in HIV: A pictorial review R. Siripurapu, D.R. Vummidi, I.W. Turnbull; Manchester/UK (rekhasiripurapu@gmail.com)

Learning Objectives: To illustrate the spectrum of neurological emergencies and their imaging features in adult patients with HIV with emphasis on the non infectious and non neoplastic causes.Background: In the current global HIV epidemic of 40 million affected people, it is estimated that one third develops neurological manifestations. They can present acutely with sudden onset headache, seizures, hemiparesis, blindness, cranial nerve deficits and Parkinsonian syndromes. The imaging in these patients not only reveals the well documented infectious and neoplastic causes, but also discloses other causes such as various types of intracranial hemorrhage, infarction and inflammation, many of which are neurological emergencies.Procedure Details: Neurological emergencies in HIV can be broadly categorized as vascular, inflammatory, infectious and neoplastic complications. The vascular complications include acute extra-axial hemorrhage, subarachnoid hemorrhage, intracerebral hemorrhage, venous sinus thrombosis, vasculitis (resulting in ischemia and infarction) and syndromes like Posterior Reversible Encephalopathy Syndrome (PRES). The inflammatory complications include Immune Reconstitution Inflamma-tory Syndrome (IRIS) and its related effects on TB, PML and lymphoma; tumefactive demyelination; hyperacute hemorrhagic demyelination; HIV encephalopathy (HIVE). An acute Parkinsonian syndrome went unrecognized as being caused by HIV for over ten years. Most of these emergencies are encountered in everyday practice and in many instances the presentation is to general physicians or neurologists who are unaware of the patients’ immune status.Conclusion: It is therefore important to recognize the imaging features of neu-rological emergencies in HIV as it has significant implications on diagnosis and management.

C-724 Central nervous system involvement in systemic diseases: Spectrum of MRI findings A. Vendrely, F. Bonneville, D. Galanaud, J.-C. Piette, D. Dormont, J. Chiras; Paris/FR (aurelie.vendrely@free.fr)

Learning Objectives: To review the pathophysiology and illustrate MRI findings of CNS lesions in patients with systemic disease.Background: The diagnosis of systemic diseases is still based on clinical features and laboratory findings. CNS involvement in systemic diseases is unusual and MRI features of such lesions unfamiliar to most radiologists. From our experience based on almost 200 cases, we here describe and illustrate the spectrum of CNS lesions encountered in systemic diseases.Imaging Findings: The most characteristic MRI findings are: micronodular lepto-meningeal enhancement, dentate nucleus, brain stem and suprasellar lesions in Langerhans cell histiocytosis, association between meningeal, orbital and facial bone involvement in Erdheim-Chester disease, contiguous invasion by an extracra-nial granuloma in Wegener, pontine veinulous lesions and cerebral thrombophlebitis in Behçet, supratentorial microvascular lesions in lupus, antiphospholipid and Gougerot-Sjögren syndromes.Conclusion: This study provides a detailed description of MRI findings of CNS lesions occurring in systemic diseases.

C-725 Primary central nervous system lymphoma: A great pretender C.H. Besada, D. Santa Cruz, J. Funes, R. García Mónaco; Buenos Aires/AR (crisbesada@gmail.com)

Learning Objectives: To present examples of various manifestations of Primary Central Nervous System Lymphoma (PCNSL) and discuss the underlying patho-physiology and multiple differential diagnoses. To evaluate the role of advanced MR techniques.Background: PCNSL is a tumor that has increased its prevalence in the last decades. It is currently a neoplasm frequently considered between the differential diagnosis of brain tumors. It may appear in immunocompetent as well as in im-munosuppressed patients. Depending on the clinical and immunological set, the radiologist may face different diagnosis: glial tumors, metastasis, abscesses, etc.Imaging Findings: There are no patognomonic imaging findings of PCNSL. Conventional imaging: CT and MRI depend on topography and contrast enhance-ment to suggest the diagnosis. There are some patterns described: parenchymal enhancement, meningeal enhancement and cranial nerves enhancement. In some occasions associated perivascular spaces enhancement may be seen. Advanced

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functional images may help in this issue. DWI shows restriction with low ADC values and perfusion shows lower rTBV compared to primary non-lymphomatous neoplasms. Typical MRS features include elevated lipid, lactate and cholina and reduced NAA signal.Conclusion: Radiologists must be aware of the various patterns of presentation of the PCNSL and its differential diagnosis depending on clinical set. They may also be aware of current MR advanced techniques that may be useful in these cases.

C-726 Diffusion-weighted imaging evaluation of subtle cerebral microstructural changes in intrauterine fetal hydrocephalus G. Erdem, O. Celik, S. Hascalik, H. Karakas, A. Alkan, A. Firat; Malatya/TR (gerdem@inonu.edu.tr)

Purpose: Hydrocephalus is an important etiological factor in neurological decline. Microstructural changes changes may theoretically be revealed by diffusion-weighted magnetic resonance imaging (DW-MRI). Our preliminary findings of DW-MRI on the hydrocephalic fetuses are presented.Methods and Materials: Twelve fetuses with fetal USG diagnosis of hydrocephalus were investigated using a 1.5-T MR scanner. In addition to conventional techniques, DWI was performed. It was obtained using a single-shot echo-planar imaging se-quence. Apparent diffusion coefficient (ADC) values were measured in the white matter of the periventricular frontal and occipital lobes, basal ganglia, thalamus, centrum semiovale and cerebrospinal fluid in the lateral ventricle.Results: All fetuses had moderate or severe bilateral hydrocephalus. On con-ventional T1- and T2-weighted imaging, cerebral parenchyma had normal signal pattern and ADC values were significantly lower than those reported for fetuses with normal brain. These values were lower in hydrocephalic fetuses with statistical significance (P .05-.01).Conclusion: DWI is a sensitive technique to investigate cerebral microstructure. The reduction in cerebral blood flow and alterations in cerebral energy metabolism in cases with hydrocephalus have been shown before. Changes in cerebral blood flow and energy metabolism, as a consequence of cerebral compression, may oc-cur in hydrocephalus. Elevated ventricular pressure may cause cerebral ischemia. The anaerobic glycolysis seen in the hydrocephalic brain tissue by increasing the lactate concentration and intracellular fluid flux may be the reason for the reduced ADC values in hydrocephalic fetuses. However, long-term prospective trials on the correlation of ADC values and neurological outcome are necessary.

C-727 Resting-state networks in healthy young, elderly and cognitive impaired individuals T. Meindl, C. Born, S. Mueller, S. Teipel, A. Bokde, M. Reiser; Munich/DE (thomas.meindl@med.uni-muenchen.de)

Purpose: To detect cortical connectivity patterns in a resting-state condition in healthy young and elderly subjects as well as patients with mild cognitive impair-ment (MCI).Methods and Materials: Resting-state functional magnetic resonance imaging at 3.0 T was performed in 15 healthy young individuals (mean age, 24.0 years), 15 healthy elderly individuals (mean age, 67.6 years) and 15 MCI patients (mean age, 69.7 years). Grouping of subjects was done by neuropsychological and genetic test-ing. Data preprocessing and statistical analysis was performed using BrainVoyager QX 1.9. Preprocessing of functional data consisted of spatial smoothing, 3D motion correction and slice-scan-time correction. Individual networks were identified by a first level single-subject independent component analysis (ICA). Group statistics were done using self-organizing group-level ICA.Results: In healthy young subjects connections between the anterior and pos-terior cingulate gyrus (ACC and PCC), the middle temporal gyrus bilaterally and the hippocampus were found. In healthy elderly individuals, activation of the ACC decreased but connectivity patterns persisted. However, no hippocampal activa-tion was detectable. In MCI, activated clusters were found in the precuneus and in the PCC. However no connection to the temporal lobe, ACC or hippocampus was found.Conclusion: Functional MRI identified changes in resting state networks during healthy and pathologic aging. This method may function as a useful approach for further understanding the pathophysiological changes associated with dementia.

C-728 Characterization and pre-surgical assessment of the corticospinal tract in patients with brain tumors using combined diffusion tensor tractography and fMRI Z. Chen, J. Xu, X. Feng, D. Geng; Shanghai/CN (chenzengai@hotmail.com)

Purpose: We used the combination of fMRI and diffusion tensor tractography to explore the spatial relationship between the corticospinal tract (CST) and the brain tumors, and to evaluate the usefulness of this modality to guide neurosurgery.Methods and Materials: 14 subjects were imaged including 12 patients with brain tumors and 2 healthy volunteers. FMRI analysis was performed with the software of SPM99, and fiber-tracking with DTV-II. DT tractography of CSTs was initiated from seed ROI based on functional MRI activations.The target ROI was placed in the cerebral peduncle. Fractional anisotropy (FA) of both CSTs at the affected side and the contralesional side were analyzed.Results: In 10 patients, the FA value in CSTs was decreased compared to healthy tissue. By contrast, a significant increase of FA was found in CSTs displaced by the tumors in 2 cases. All the subjects succeeded in the tractography of CSTs using the method of fMRI-based seed ROI placement. Displacement or disruption of CSTs can be seen, and the anatomical relationship among the lesions and the CSTs were clearly revealed. In 2 patients who performed finger and foot tapping, the hand and foot fibers could be distinguished.Conclusion: The combined use of DT tractography and fMRI is helpful for identifying the relationship among the tumors, the CSTs and the eloquent cortical areas, but this information cannot be obtained from conventional DT tractography based on anatomic landmarks. It is also an important technique to aid surgical resections.

C-729 Amyotrophic lateral sclerosis: Correlation of fractional anisotropy values with clinical and neurophysiologic findings T. Gerukis, C. Hatzigeorgiou, A. Petridis, P. Sidira, V. Kimiskidis, S. Papagianopoulos, V. Kalpakidis, P. Palladas; Thessaloniki/GR (gerukis@yahoo.gr)

Purpose: To investigate the correlation between amyotrophic lateral sclerosis functional rating scale (ALSFRS), central motor conduction time (CMCT) and fractional anisotropy (FA) values in MRI, in patients with ALS.Methods and Materials: We studied 13 patients with E1 escorial definite, prob-able, or possible ALS from 51 to 75 years old. All patients were evaluated clinically according to ALSFRS. We assessed CMCT subtracting the cervical-muscle latency from motor cortex-muscle latency using transcranial magnetic stimulation. Diffusion tensor imaging (DTI) was performed and was followed by post-processing of data with generation of fractional anisotropy maps, tractography of corticospinal tracts (CST) and corticobulbar tracts (CBT) and measurement of FA values. Statistical analysis was performed by means of “Kendall’s tau_b” and “Spearman’s rho” cor-relation coefficient.Results: The statistical analysis showed a significant correlation of ALSFRS with CMCT (p=0.000), CST FA-values in the pontine (p=0.017) and basal ganglia (p=0.001) but no significant correlation with CST-FA in the corona radiata (p=0.244) and CBT-FA in the pontine (p=0.323). There was also a significant correlation of CMCT values with the values of CST-FA in the pontine (p=0.009) and posterior limb of the internal capsule (p=0.001), but no significant correlation with CST-FA in the corona radiata (p=0.121) and CBT-FA in the pontine (p=0.652).Conclusion: DTI with measurements of FA in the CST is a reliable method which can contribute to the evaluation of the severity and the progress of ALS. The results are preliminary considering the small number of subjects in the study.

C-730 The anterior pontomesencephalic-anterior medullary venous system and its bridging veins communicating to the dural sinuses: Normal anatomy and drainage routes from dural arteriovenous fistulas H. Kiyosue, S. Tanoue, Y. Sagara, J. Kashiwagi, Y. Hori, M. Okahara, Y. Kondo, S. Matsumoto, H. Mori; Oita/JP (hkiyosue@med.oita-u.ac.jp)

Purpose: We evaluate the normal venous anatomy of the anterior medullary/an-terior phontomesencephalic venous system (MAMV/APMV) and its bridging veins connected to the dural sinuses by using MRI and demonstrate cases of DAVFs with the bridging venous drainage.Methods and Materials: MR venography using 3D gradient echo sequence in 70 patients was reviewed to evaluate the normal anatomy of the MAMV/APMV system and the bridging veins. MR images and/or DSA in cases with DAVFs were reviewed to evaluate the bridging venous drainage from DAVFs.

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Results: MR venography could clearly depict MAMV/APMV in 35 cases. Direct connection between MAMV and APMV was found in 15 cases, and indirect com-munication via the transverse pontine vein or the bridging vein was found in 15 cases. In the remaining 5 cases, the MAMV and/or APMV end to the bridging vein or the transverse pontine vein. The bridging vein was identified in 34 cases, which connected to the cavernous sinus in 33, to the suboccipital cavernous sinus in 11, and to the inferior petrosal sinus in 5. In the cases of DAVF, cavernous sinus DAVFs were often drained via the bridging vein to the brain stem. Cervical spinal DAVFs could also be drained via the bridging vein and MAMV/APMV system.Conclusion: This paper demonstrated several anatomic variations of the MAMV/APMV and the bridging veins which frequently connected to the cavernous sinus. The knowledge of this venous anatomy would be helpful for diagnosis and intra-vascular treatment of DAVFs.

C-731 Fractional anisotropy of early degenerative pyramidal tract predicting outcome of motor function after ischemic stroke C. Yu, K. Li; Beijing/CN (chunshuiyu@yahoo.cn)

Purpose: To investigate whether fractional anisotropy (FA) of the early Wallerian degenerative pyramidal tract due to ischemic stroke can predict the motor deficit at the third month from onset using diffusion tensor imaging (DTI).Methods and Materials: DTI was performed in 15 patients (13 males and 2 females) with acute ischemic stroke involved in the internal capsule at the second week from onset. National Institutes of Health Stroke Scale (NIHSS), Bathel index (BI), modified Rankin scale (mRS) and Motricity index (MI) were assessed for each patient at the second week and the third month from onset. The correlations between these clinical scales and the FA of the degenerative pyramidal tract at the level of the superior slice of the cerebral peduncle (CPSFA) were evaluated.Results: At the second week from onset, we found positive correlations between CPSFA and BI (r = 0.530, P = 0.042) and between CPSFA and MI (r = 0.543, P = 0.036), and a negative correlation between CPSFA and NIHSS (r = -0.613, P = 0.015). At the third month from onset, the MI was positively correlated with the CPSFA at the second week from onset (r = 0.565, P = 0.028), and the mRS was negatively correlated with the CPSFA at the second week from onset (r = -0.600, P = 0.018).Conclusion: Measurement of the FA of the early degenerative pyramidal tract has the potential to predict the outcome of the motor function after ischemic stroke.

C-732 Hippocampal volumetry: A review S.K.V. Bommana1, U.D. Patil1, R.M.S.V. Vadapalli2, B.Y.T. Arya1, R.H.N. Hanasoge1; 1Bangalore/IN, 2Colombo/LK (bommanasubhash@yahoo.com)

Purpose: 1. To discuss the various disorders associated with hippocampal vol-ume reduction. 2. To understand the usefulness of hippocampal volumetry in the diagnosis of these disorders. 3. To discuss the various methods of hippocampal volumetry.Methods and Materials: Patients undergoing MRI evaluation of epilepsy and de-mentia were selected retrospectively and volumetric analysis of the hippocampus was done and correlated with the clinical scenario. This poster will highlight the most useful methods of hippocampal volumetry.Results: Hippocampal atrophy is seen in most cases of mesial temporal sclerosis and in Alzheimer’s dementia and correlates with clinical scenario and possible outcome better than other disease specific features like T2 hyperintensities in mesial temporal sclerosis.Conclusion: Hippocampal sclerosis and Alzheimer’s dementia are characterized by hippocampal volume reduction which correlates best with clinical outcomes. This poster focuses on the various hippocampal volumetric analysis methods.

C-733 Human lymphotropic virus type I associated myelopathy/tropical spastic paraparesis: Diffusion tensor imaging evaluation of brain lesions E.L. Gasparetto, L.C.H. da Cruz Jr, F. Palma, T. Doring, G. Taboada, M.T. de Freitas, R.C. Domingues, R.C. Domingues; Rio de Janeiro/BR (celsohygino@hotmail.com)

Purpose: To evaluate the diffusion tensor imaging (DTI) abnormalities in the brain lesions of patients with HTLV I associated myelopathy/tropical spastic paraparesis (HAM/TSP).Methods and Materials: We studied 11 cases of HAM/TSP and an age- and gen-der-matched control group. All patients underwent brain MRI at 1.5 T scanner, with conventional protocol and DTI (64 directions). The DTI data were post-processed and fractional anisotropy (FA) maps calculated. The FA values were measured in

ROIs positioned in the white matter lesions, normal-appearing white matter (NAWM) around the lesions, as well as NAWM more than 1 cm distant from the lesions and contralateral. In the control group, the ROIs were placed in regions similar to the lesions of the study group. The FA values were compared between the groups, and the statistical treatment was performed with the Mann-Whitney U test.Results: The FA values were significantly reduced in the white matter lesions (mean FA= 0.285) and in the NAWM around the lesions (mean FA= 0.386) compared with controls (mean FA= 0.662) (p0.05).Conclusion: The DTI allows accurate evaluation of the white matter lesions in patients with HAM/TSP. Our results demonstrated reduced FA values in the lesions and NAWM around them, but no significant abnormalities in the NAWM distant from the lesions or contralateral.

C-734 Diagnosis of brain death: Underestimated role of MSCT angiography? E. Czekajska-Chehab, J. Bicki, S. Uhlig, G. Staskiewicz, J. Wojczal, S. Rudzki, A. Drop; Lublin/PL (uhlig.s@eranet.pl)

Purpose: Diagnosis of brain death bases upon demonstrating the lack of brain-stem function. Arrest of cerebral circulation revealed by radiological examinations is one of the factors confirming brain death. The aim of the study was to describe the changes in the brain and its vascularization detected by MSCT angiography in patients with clinical diagnosis of brain death.Methods and Materials: We evaluated MSCT angiography examinations of 23 patients with features of post-traumatic or stroke-induced brain damage, in whom brain death was confirmed using binding clinical examinations. The examinations were conducted using native axial scanning followed by the intravenous contrast medium bolus (collimation 1.2 or 0.6; 80 or 100 ml of contrast medium, 370 mgI/ml). Axial scans, MPR projections with MIP option and volume rendering protocols were used to evaluate cerebral and vascular changes.Results: The analysis of CT scans revealed the following changes in all patients: severe brain oedema without visible sulci, compression of brain ventricles, no delineation between white and gray matter, homogeneity and hypodensity of brain tissue. In 18 patients, MSCT angiography revealed the arrest of circulation in internal carotid and vertebral arteries enabling the diagnosis of lack of cerebral circulation with preserved flow in the branches of external carotid artery. In 5 cases, slight contrast filling of all or single intracranial arteries was noticeable.Conclusion: MSCT angiography may be a useful diagnostic tool confirming cerebral circulation arrest and vestigial contrast filling of intracranial arteries do not exclude brain death. Moreover, it gives opportunity of precise evaluation of brain lesions.

C-735 Performance evaluation of radiologists with artificial neural network for differential diagnosis of intra-axial brain tumors on MR images K. Yamashita, T. Yoshiura, H. Arimura, Y. Yamashita, F. Mihara, T. Noguchi, A. Hiwatashi, O. Togao, Y. Higashida, H. Honda; Fukuoka/JP (yamakou@radiol.med.kyushu-u.ac.jp)

Purpose: Our purpose in this study was to apply an artificial neural network (ANN) for differential diagnosis of intracranial brain tumors on magnetic resonance (MR) images and evaluate the effect of ANN outputs on radiologists’ diagnostic performance.Methods and Materials: We collected 126 cases of intra-axial cerebral tumors (58 high grade gliomas, 37 low grade gliomas, 19 malignant lymphomas, and 12 metastatic tumors). We used a single three-layer feed-forward ANN with a Levenberg Marquardt algorithm. The ANN was designed to differentiate four tumor categories [high grade gliomas (grade III or IV), low grade gliomas (grade I or II), malignant lymphomas, and metastasis] by using two clinical parameters and 13 radiological findings in MR images. Thus, the ANN consisted of 15 input units and four output units. Subjective ratings for the 13 radiological findings were provided independently by two attending radiologists. All 126 cases were used for training and testing of the ANN based on a leave-one-out-by-patient method. In the observer test, MR images were viewed by nine radiologists first without and then with ANN outputs. Radiologists’ performance was evaluated by using a receiver operating characteristic (ROC) analysis on a continuous rating scale.Results: Averaged area under the ROC curve for ANN alone was 0.949. The diag-nostic performance of nine radiologists increased from 0.899 to 0.946 (P 0.001) when they used ANN outputs.Conclusion: The ANN can provide useful output as a second opinion to improve radiologists’ diagnostic performance in the differential diagnosis of intra-axial cerebral tumors seen on MRI.

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C-736 Perfusion MRI: Does it beat pathology? A. Hilario, A. Ramos, P. Gonzalez, A. Perez, S. Jimenez, A. Alcala-Galiano; Madrid/ES (amayahilario@yahoo.es)

Purpose: To investigate the efficiency of perfusion MRI in discrimination of high- and low-grade gliomas as a method complementary to biopsy and surgery. To compare baseline relative cerebral blood volume (rCBV) with histopathology and tumor progression in order to provide a second reference standard in the manage-ment of gliomas.Methods and Materials: Determinations of maximal rCBV were performed in 78 subjects with histopathologically confirmed gliomas. Comparison and difference of rCBV between high- and low-grade gliomas were obtained. To avoid potential diagnostic error with biopsy samples, we studied the differences of rCBV in patients grouped in clinical response categories. Correlation was also established between rCBV and histopathological criteria for malignancy.Results: In high- and low-grade gliomas, rCBV value was measured as 3.80 1.69 and 2.26 1.47 (mean SD), respectively (p=0.002). Differences are higher 3.73 1.7 vs 1.73 0.86 (p 0.001) if we consider patients in different response categories (complete or stable response vs progressive or death). Other gliomas (e.g. oligo-dendrogliomas) have high rCBV regardless of grade. No relation was demonstrated between rCBV value and cellular atypia. Mytotic activity was associated to a mean rCBV value of 3.55 (p=0.01). Mean rCBV value for gliomas with microvascular proliferation was 4.02 (p=0.01). Gliomas with tumoral necrosis demonstrated a mean rCBV value of 3.80 (p=0.018).Conclusion: In low grade gliomas, rCBV is more accurate in predicting tumor progression than histological data obtained by brain biopsy. rCBV value dem-onstrates a strong correlation with tumoral clinical behaviour, even better than histopathological criteria.

C-737 Diffusion changes in peritumoral tissue after surgery for glioblastoma: Possible prediction of radiotherapy response J. Qu, T. Jiang, L. Ai, S. Li, J. Dai; Beijing/CN (qjryq@yahoo.com.cn)

Purpose: Changes in apparent diffusion coefficient (ADC) peritumoral tissue on patients during treatment of newly diagnosed glioblastoma before and middle radia-tion therapy were evaluated, and then the therapeutic efficacy of ADC measurement was assessed. Special emphasis has been given to these imaging technologies as tools to potentially anticipate disease progression, as progression-free survival is frequently used as a surrogate endpoint.Methods and Materials: In 28 glioblastomas after surgery, diffusion-weighted imaging within 1 week before and 3 weeks after radiation therapy was performed. The nADCs were compared with the change in tumor size of 4 and 16 weeks after radiation therapy. Classical criteria on tumor size variation and clinical parameters were used to set the disease progression date.Results: The nADC of the peritumorals was significantly higher 3 weeks after radiation therapy compared with that before radiation therapy. A significant differ-ence in the nADC at 3 weeks after radiation therapy was observed between the responder and nonresponder groups.Conclusion: Changes in nADC as measured by diffusion-weighted imaging can predict the response of glioblastoma after surgery to radiation therapy.

C-738 Relationship between CT perfusion and brain tissue oxygen tension in head trauma patients: Preliminary results M.J. Picado, J. Pérez-Bárcena, A. Mas, A. Moll, J. Ibañez, J.A. Llompart, M. Brell; Palma de Mallorca/ES (mjpicado@hsd.es)

Purpose: Monitoring of intraparenchymal brain tissue oxygen tension (PbrO2) is an emerging tool in neurocritical care. Current intraparenchymal monitors provide focal measurements of PbrO2 and their target are the white matter of one hemisphere. The use of CT perfusion (CTP) has not been thoroughly evaluated in traumatic brain injured (TBI) patients where tissular hypoxia is due to multiple causes. The purpose of this study is to determine if there is a relationship between CTP imaging parameters (MTT, CBV, CBF) and PbrO2 values.Methods and Materials: 9 patients underwent continuous PbrO2 monitoring with catheters placed into the white matter of frontal lobes. The ROI selected was sur-rounding the oxygen probe. CTP analysis software was used to measure the MTT, CBF and CBV in the ROI described previously. For correlation, PbrO2 levels and other physiologic parameters were recorded at the time of CTP.Results: PbrO2 minimum and maximum values at the time of CTP were: 11-113 mmHg; MTT were 2.3-10 seconds; CBV were 1.1-7.7 ml/100 g; and CBF was

13.9-98.5 ml/100 g/m. PbrO2 was correlated with CBF (r=0.83; p=0.05). MTT or CBV were not correlated with PbrO2. PbrO2 also correlated with the CBF of the ROI located at the anterior cerebral artery region (r=0.73; p=0.02) but not with the middle and posterior cerebral arteries.Conclusion: CTP assessment of ROI surrounding an oxygen probe in the pa-renchymal brain tissue is feasible and showed a significant correlation between PbrO2 and CBF.

C-739 Treatment of intracranial aneurysms with Leo stent: A long-term follow-up study J.M. Pumar, L. Lopez-Carreira, S. Baleato, C. Ruibal, M. Blanco, F. Vazquez; Santiago de Compostela/ES (mrpumar@usc.es)

Purpose: The preliminary experience with the Leo microstent in combination with detachable coils for the treatment of patients with cerebral aneurysms is reported, and the technical complications and recommendations for optimum placement and deployment are discussed. We present a long-term follow-up data.Methods and Materials: 32 patients identified as harboring wide-necked aneu-rysm were selected for stent-assisted coiling. Aneurysms were paraophthalmic in 10 cases, 14 were located at the cavernous segment of the internal carotid artery, and 8 at the posterior communicating artery. After appropriate antiplatelet therapy, the Leo stent was delivered to the aneurysm site and positioned without difficulty. Angiographic follow-up was undertaken at six-months in 32 patients, at one year in 27 patients, and at two years in 20 patients.Results: Stent placement in the desired position with complete or near complete occlusion of the aneurysm was feasible in all patients. In one patient, the stent was slightly displaced during microwire manipulation for aneurysm microcatheterization through the stent mesh. Two-year angiography in 20 patients showed 18 complete occlusions and 2 aneurysms with a minimal residual neck.Conclusion: The Leo stent represents a significant advancement in the vascular treatment of intracranial aneurysms providing high radial force and an easy delivery system i.e., it is a feasible, secure and effective system.

C-740 3D diffusion weighted whole body imaging in patients with solitary brain metastases M.B. Dolgushin, L.M. Fadeeva, A.Y. Zaitceva, I.N. Pronin, P.V. Rodionov, V.N. Kornienko; Moscow/RU (mdolgushin@mail.ru)

Purpose: To evaluate informativity of 3D DWI whole body imaging in detecting metastatic lesions expansion in patients with solitary brain metastasis.Methods and Materials: 12 patients with solitary metastatic lesions detected by standard MRI imaging (T1, T2, T1 Gd) were investigated. 3D DWI whole body imag-ing (TR=7000mc, b=1000c/mm2, thickness=5 mm, voxel=0.23x0.23x0.5, TA=4 min) was conducted for all patients during the same acquisition. DWI data (120-150 axial scans on two levels) were processed off-line (MIP or MPR with gray scale inversion) and PET-like 3D image was built. PET (18FDG) was used as a control method. The detection of metastatic expansion was determined by low intensity areas on 3D DWI PET-like images. The numbers of lesions were evaluated on MRI and PET images. The histological verification was made in all cases.Results: 3D DWI whole body imaging allows to suspect the primary cancer source: breast (4 cases), lung (3), melanoma (3), kidney (1) and colon (1). Tumor nodes were seen as dark areas on PET-like DWI and PET images. 3D DWI data were characterized by high false positive predictive values (28%) in comparison with PET in the areas containing fluid in thoracic/abdominal sinuses, in colon and edematous parenchymal organs. However all metastases, detected by PET, were characterized by high diffusivity on whole body 3D DWI.Conclusion: 3D DWI whole body imaging allows for evaluating the expansion of cancer process in patients with brain metastasis. 3D DWI PET-like images give additional information about the sources of cancer in whole body. In short, the diagnostic time and may be used as screening method.

C-741 Proton magnetic resonance spectroscopy (MRS) in the evaluation of diffuse axonal injury W.B. Zheng, Y.L. Guo, H.D. Zhang; Shantou/CN (hwenb@21cn.com)

Purpose: To determine whether proton magnetic resonance spectroscopy (MRS) would be useful in the evaluation prognosis of the patients resulting from diffuse axonal injury.

Methods and Materials: 41 victims of traumatic brain injury who were in the coma state immediate and prolonged unconsciousness between 1 day and 21 days after

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injury underwent MRI and MRS studies. Convention MR imaging consisted of spin-echo T1-weighted imaging, T2-weighted imaging, fluid-attenuated inversion recovery and T2*-weighted gradient-echo sequences. The N-acetyl aspartate to creatine (NAA:Cr) and choline to creatine (Cho:Cr) ratios were obtained for each patient. The proton occipital lobe MRS and the corpus callosum MRS studies of 41 patients were compared with ten healthy volunteers.Results: Twenty-one patients with normal-appearing and twenty patients with visibly-injured corpus callosum, and all patients with normal-appearing in occipital lobe on convention MR imaging. A significant decrease in N-acetylaspartate (NAA)/creatine (Cr) and increase in choline (Cho)/Cr (evidence of DAI) was observed in the corpus callosum (P 0.05) and in occipital lobe (P 0.001) compared with controls. In normal-appearing brain, NAA/Cr decreased more in patients with poor outcomes (1.32 0.5) than in those with good outcomes (1.81 0.5, P =0.01) or control subjects (2.16 0.1, P =0.00). In predicting outcomes, ratios from visibly-injured, normal-appearing in corpus callosum and in occipital lobe were 57, 81 and 87% accurate, respectively.

Conclusion: MRS depicts injuries in brain that appear normal on imaging are more accurate for predicting long-term outcomes than those that appear unnormal

on imaging.

C-742 Proton MR spectroscopy in the evaluation of axonal injury: Correlation with clinical outcome after traumatic brain injury W.B. Zheng, R.W. Chen, C.L. Ma; Shantou/CN (hwenb@21cn.com)

Purpose: To evaluate the utility of proton MR spectroscopy in identifying patients with neuronal injury after TBI.Methods and Materials: Thirty-nine patients with diffuse axonal injury, aged 17-51 years; admission Glasgow coma scale scores 3-14, were studied on a 1.5-T system with MR spectroscopy of the splenium. Scans were obtained 7 to 21 days after injury (median, 11 days). Proton MR spectroscopy was used to calculate the N-acetylaspartate (NAA)/creatine (Cr) ratio of the splenium. NAA/creatine (Cr) in the splenium in patients compared with normal control volunteers.Results: Compared with normal control volunteers, decreased NAA/Cr radios were identified in 39 patients in the posterior commissure of the corpus callosum. In 20 patients with a GCS of 3 to 8, the mean NAA/Cr was 1.23 0.27; In 19 patients with a GCS of 9-14, the mean NAA/Cr was 1.89 0.31 (P 0.05); NAA/Cr ratios were lower in the group of patients who remained in a persistent coma state than in the group of patients who regained awareness after being in the coma state (p 0.001).

NAA/Cr in splenium was also correlated with coma duration of the patients.Conclusion: MR spectroscopy can quantify damage after TBI, NAA /Cr in splenium correlated significantly with length of coma duration (as a possible surrogate marker for short-term outcome). NAA/Cr in splenium may be a sensitive indicator of the neuronal damage that results in a worse clinical outcome.

C-743 Non-invasive assessment of brain masses using susceptibility weighted imaging L. Guan, S. Li, K. Xu; Shenyang/CN (guanlm@sohu.com)

Purpose: To evaluate the characteristics of brain masses using susceptibility weighted imaging (SWI).Methods and Materials: A series of 34 patients (16 males and 18 females, 13-83 years old, mean age=47 years) with brain masses (39 lesions) had both CT and MR imaging (MRI) scans with SWI. SWI is a new high-resolution, fully velocity-compensated gradient-echo sequence that amplifies phase to enhance the magnitude contrast.Results: In SWI, the signal intensity of tumor parenchyma which showed contrast enhancement on T1 postcontrast images was similar to that of gray matter and that of other part and edema was similar or higher than that of white matter. SWI displayed distinctly venous vasculature and microhemorrhage within the tumors that could not be seen with conventional MRI and CT. The venous vasculature was more irregular and hemorrhage was more visualized in high-grade gliomas (3/7) and 14 metastases. 4 untreated metastases showed homogeneously low signal and others, which had achieved chemo- and/or radio therapy before, showed heterogeneous signal. AVM and cavernous angioma (14/39) were visualized well in SWI, better than conventional MRI and CT, especially small lesions. For 2 old lesions, one could not display abnormal signal in SWI while high signal in T1-weighted images and high density on unenhanced CT, the other showed low signal in most regions in SWI.Conclusion: SWI could demonstrate the architecture and component of brain masses and provide special information for diagnosis and treatment. SWI could be used for diagnosis of small metastases and vascular malformation.

C-744 Functional connectivity analysis for paranoid schizophrenic patients in resting state and digital 2-back task Q. Zhang, Y. Zhang, W. Li, H. Ren; Tianjin/CN (zhangquan0912@163.com)

Purpose: To examine the differences of functional connectivity between paranoid schizophrenic patients and normal subjects in resting state and digital 2-back working memory task, and to detect the functional disintegration in paranoid schizophrenic patients.Methods and Materials: This study included nine patients with paranoid schizo-phrenia (6 male, 3 female; age range 20-50, average 33.6 11.3; course of disease, 1-9 years; diagnosed according to DSM-IV) and nine matched healthy subjects. Informed consent was obtained from all subjects and patients. Block-designed fMRI was acquired by using GE Twinspeed 1.5 T MR scanner with GRE-EPI sequence (TR/TE, 2000/60 ms; Matrix, 64×64; thickness, 5 mm; slice gap, 1 mm). Resting state and digital 2-back working memory task were adopted. The fMRI data were processed with the software of AFNI and Matlab. Based on seed voxels method, we analyzed the time course correlation between DMPFC (BA 6, 66, 15) and the other brain areas, and the cross-correlogram was obtained as the output. The cor-relation between differences of functional connectivity and behavior performance were also analyzed.Results: A wide abnormal functional connectivity network occurred in limbic system which included the brain areas around lateral fissure, paracentral lobule, anterior nuclei of thalamus and in prefrontal and parietal cortex-thalamus-cerebel-lum circuit.Conclusion: The results indicated that the paranoid schizophrenic patients pres-ent with wide conversion deficits in functional connectivity and entirely disrupted functional integration.

C-745 Working memory in mild cognitive impaired subjects in comparison with healthy young and elderly controls T. Meindl, C. Born, S. Hoehler, A. Bokde, S. Teipel, M. Reiser; Munich/DE (thomas.meindl@med.uni-muenchen.de)

Purpose: The purpose of this study was to evaluate differences in brain activation in patients with mild cognitive impairment (MCI) in comparison with young and elderly controls in a working memory task.Methods and Materials: Ten healthy young individuals (mean age: 28 years, m:f = 5:2), 10 healthy elderly subjects (mean age: 70.1 years, m:f = 5:2, MMSE=29.3) and 10 MCI patients (mean age: 69.7 years, m:f = 4:3, MMSE=27.1) underwent a functional magnetic resonance imaging (fMRI) visual working memory task at 1.5 T. Data processing and statistical analysis was done by BrainVoyager QX 1.7.4. Task performance was recorded. Group statistics and group differences were evaluated by a random effects model.Results: Task performance did not differ among the groups. In the young controls, activations were observed in the hippocampal and parahippocampal region, the prefrontal cortex right-sided and the fusiforme gyrus. The healthy elderly controls showed a similar activation pattern with additional activations within the left parietal cortex. The MCI group exhibited a loss of prefrontal hemispheric lateralization with activations of the prefrontal cortex bilaterally and increased bilateral parietal activation. Neither the elderly control group nor the MCI patients showed hippo-campal activation.Conclusion: Activation patterns and hemispheric lateralization in working memory remain stable during aging. However, elderly individuals recruit additional cortical areas. In contrast, mild cognitive impaired patients show a clear loss of hemispheric lateralization and the utilization of additional cortical areas and networks to maintain memory function.

C-746 MRS thalamus metabolic changes and clinical test correlation in schizophrenic patients with and without auditory hallucinations B. Martínez-Granados1, M.C. Martínez-Bisbal1, J. Sanjuan2, O. Brotons2, L. Martí-Bonmatí2, B. Celda1; 1Burjassot (Valencia)/ES, 2Valencia/ES (m.beatriz.martinez@uv.es)

Purpose: To study if schizophrenic patients with auditory hallucinations may show thalamus metabolic alterations in comparison with those patients without auditory hallucinations and control subjects.Methods and Materials: MRS studies (1.5 T unit) were performed in 44 male and 5 female schizophrenic patients (31 hallucinators and 18 not hallucinators, 41 11 years) and 31 controls (31 8 years). A 1H MRS imaging with 2 transversal slices (TR/TE 2700/272 ms, region of interest 110x100x23 mm) was acquired. In the

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quantitative analysis four elements of volume (9.2x9.2x23x4 mm), added into one spectrum representative of each thalamus, were chosen in the lower slice. The areas of metabolites were integrated with jMRUI program. SPSS 14.0 program was used for statistical analysis.Results: A significant reduction of NAA/Cho value was observed in right thalamus in schizophrenics vs. controls. Cho/Cr value at the right thalamus was higher in hallucinators followed by not hallucinators and controls. Moreover, NAA/Cr in schizophrenics was lower than in controls in both, right and left thalamus although without statistical difference. In all groups, bilateral statistical differences were found in right vs. left hemispheres metabolites ratios. In addition, there was a significant correlation between several metabolite ratios and clinical test (BPRS, PANSS and PSYRATS) and chlorpromazine equivalent dose of medication.Conclusion: Thalamus has been considered as an implicated region in schizophrenia and alterations in this structure or function have been previously described. Cho and NAA ratios in our study reflect a differential thalamic metabolism pattern in schizo-phrenics particularly in those with auditory hallucinations compared with controls.

C-747 Understanding in-vitro poor cerebrospinal fluid suppression on gadolinium-enhanced FLAIR images L. Roccatagliata1, L. Bonzano1, F. Levrero1, G.L. Mancardi1, F. Sardanelli2, G. Cornalba2; 1Genova/IT, 2Milan/IT

Purpose: Blood-brain barrier disruption with extravasation of Gadolinium (Gd)-based agents into CSF can shorten T1 relaxation times and reduce fluid suppres-sion on FLAIR sequences. Gd extravasation could be detected by FLAIR even at low concentration. We investigated in-vitro reduced fluid suppression on FLAIR images in presence of Gd.Methods and Materials: We mixed Gd-DTPA (Magnevist-Schering) with artificial CSF. Solutions with Gd-DTPA concentrations (microM) of 0, 0.61, 1.22, 2.44, 4.88, 9.77, 19.53, 39.06, 78.13, 156.25, 312.50, 625, 1250, 2500 were placed in tubes and studied by MR at 1.5 T with FLAIR (TR/TE/TI 9002/128.52/2200 msec). To calculate T1 and T2 relaxation times, spin-echo images were acquired at multiple TRs (60, 120, 240, 500, 750, 1000, 2000 msec) and fixed TE (16 msec) or at multiple TEs (50, 100, 150, 175, 200, 350, 525, 700 msec) and fixed TR (2000 msec). T1 and T2 maps were obtained. Mean signal intensity (SI) of each tube was calculated on FLAIR images.Results: SI on FLAIR images increases with Gd concentration reaching a peak at 312.50 microM, then progressively decreases until a value close to that of pure artificial CSF at a concentration of about 2.250 microM. Increasing agent concentration, T1 values progressively reduce from 3740 to 110 msec. T2 values progressively decrease becoming the principal determinant of SI drop at higher Gd-DTPA concentrations.Conclusion: Low Gd-DTPA concentrations impair fluid suppression efficacy of FLAIR imaging in association with progressively reduced T1 values. At higher concentrations, the prevalent T2 effect can explain progressive SI reduction.

C-748 Regional fiber degeneration in the corpus callosum monitored by fractional anisotropy correlates to FLAIR hypodensities and black holes in MS patients B. Bellenberg1, C. Lukas1, A. Haghikia1, M. Fischer1, J. Klein2, H.K. Hahn2, C. Beste1, M. Hausmann1, O. Köster1, S. Schimrigk1; 1Bochum/DE, 2Bremen/DE (B.Bellenberg@elis-stiftung.de)

Purpose: Corpus callosum (CC) white matter fiber integrity in Multiple Sclerosis (MS) can be monitored by Diffusion Tensor Imaging (DTI). T1 hypointense lesions represent chronical tissue damage, while FLAIR hyperdense areas in the CC are seen already in early MS. In this study correlations between DTI results, FLAIR hyperdense areas and black holes are assessed in 7 functional different callosal segments.Methods and Materials: For 14 patients with secondary progressive MS (age: 32- 59 years, mean: 46 years) and 16 matched healthy controls, axial EPI DTI datasets (6 gradient directions, 10 repetitions) and thin sliced sagittal T1 weighted and FLAIR images were acquired at 1.5 T and postprocessed using the MeVisLab© software. CC was subdivided into 7 segments to evaluate local fractional anisotropy (FA), mean diffusivity (MD), black holes and FLAIR hyperdensities. The segments correspond to the cortical regions: 1, 2, 3 - frontal / prefrontal, 4, 5 - sensorimotoric, and 6, 7 - parietal/midtemporal/occipital areas. Correlations between conventional and DTI based quantitative results were assessed.Results: In all segments, age-corrected values of FA were significantly reduced (respectively increased) in MD in patients compared to controls. FLAIR lesions were frequently found in all segments, compared to fewer black holes. Significant

negative resp. positive correlations were shown between FA resp. MD and the relative areas of FLAIR hyperintensity in sections 2, 3, 4, 6, 7. In segments 2, 3 black holes were significantly correlated to abnormal DTI results.Conclusion: Hyperintense areas seen in FLAIR images are better predictors for abnormal regional FA and MD results than T1 hypointense lesions.

C-749 Regional quantification of brain cerebral blood volume maps using the Talairach proportional grid system J. Guzman, S. Reig, J. Olazaran, I. Cruz, E. Navarro, D. Ezpeleta, J.M. Mateos, V. García, M. Desco; Madrid/ES (jguzman.hgugm@salud.madrid.org)

Purpose: We propose a new method for regional quantification of brain Cerebral Blood Volume (CBV) maps obtained by MR perfusion weighted images using structural MRI images and the Talairach proportional grid system.Methods and Materials: The anatomical information from the MRI is used to build a Talairach grid system, and a co-registered CVB map image is superimposed on the grid for a complete regional measurement of brain CVB. Our implementation of the Talairach method followed three steps: 1) brain extraction of the MRI; 2) registration of CVB maps and MRI for each subject; and 3) construction of the Talairach grid on each brain and quantification of its regional CVB. The Talairach grid system allowed us to define brain regions of interest (ROI) as sets of 3D volume grid cells. Using this method we were able to obtain volume and CBV data for the whole brain and for the frontal, parietal, occipital and temporal lobes, for each hemisphere.Results: To illustrate the method for neurological research, we applied our technique to compare CBV maps from 19 Alzheimer patients classified into two degrees of cogni-tive impairment: mild (CDR=0.5) and very mild (CDR=1). Patients with mild dementia (n=11) showed significantly lower CBV values in the temporal lobe (p 0.001).Conclusion: This semiautomatic technique allows detailed regional measurements of CBV for the GM only or the whole brain tissue. The results obtained suggest that we can distinguish between different degrees of cognitive impairment in the early onset of AD.

C-750 Non local means filter enhances fMRI signal detection J.J. Lull, J.V. Manjón, G. García-Martí, L. Martí-Bonmatí, M. Robles; Valencia/ES (jmanjon@fis.upv.es)

Purpose: The Non Local Means (NL-Means) filter, already applied to structural MR images, has not yet been applied to the fMRI preprocessing. The purpose is to show how the well-known NLM filter can recover the original signal in the fMRI data better than the nowadays methods do.Methods and Materials: An fMRI phantom was created with the mean of three EPI volumes. Afterwards, the phantom was replicated 100 times and the ideal hemo-dynamic response function and rician noise were added. Three filtering methods were compared: NL-means, Gaussian and adaptive bilateral filtering. Comparisons were carried out by measuring the functional Signal-to-Noise-Ratio (fSNR) and Root-Mean-Square-Error (RMSE). NL-Means was applied with a search window of 7x7x7 voxels and a similarity window of 3 x 3 x 3 voxels. The adaptive bilateral and Gaussian kernels were of 7x7x7 voxels.Results: The NLM filter resulted in both a reduced RMSE and increased fSNR compared to both the Gaussian filtering and the adaptive bilateral filtering. RMSE was 95.37 (fSNR 22.26) for NL-means while 121.92 (fSNR 2.031) for Gaussian filtering, for an image with noise added 5% and hemodynamic signal 5%.Conclusion: By using NL-means instead of other basic fMRI filtering techniques (i.e. the most common ones: Gaussian filtering and bilateral filtering), we can obtain a much better signal. fSNR can be enhanced even up to ten times compared to bilateral or Gaussian filtering (in the example image, an increase of four times was obtained). NL-means is a very promising method that should be applied to fMRI.

C-751 Artifacts during MRI of the brain at 3 Tesla: Types and remedies M. Spirovski1, K.M. Koprivsek1, M.A. Lucic1, V. Zlokolica2, D. Kozic1, P.M. Parizel3; 1Sremska Kamenica/RS, 2Novi Sad/RS, 3Antwerp/BE (medenica2000@yahoo.com)

Purpose: Artifacts are commonly encountered during MRI of the brain at 3 T. The purpose of this presentation is to present an inventory of artifacts and to propose ways to avoid them.Methods and Materials: During a period of 6 months, 1260 MR examinations of the brain were performed using a 3 T system (Magnetom-Siemens-Trio-TIM). Artifacts were assessed in consensus by 2 independent reviewers and were found in 78.3% of all studies.

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Results: Artifacts were categorized as: pulsatile-flow artifacts (along the phase-encoding direction) in 89% of the patients, chemical shift (in the frequency-encoding direction) 22.7%, susceptibility (near the skull base) 34.3%, metal artifacts 35.6%, and a group of other less frequent artifacts in 3%. Flow artifacts, found in most of the cases, caused by pulsatile-motion of blood or CSF, were predominantly localized at the craniocervical junction, in the preopontine cistern, near the circle of Willis and adjacent to the foramina of Monro. Chemical shift artifacts were com-monly encountered near the sella turcica, but rarely caused diagnostic problems. Susceptibility artifacts are more pronounced at 3 T than at 1.5 T and are especially found near the air-containing structures of the skull base; they are more prevalent on GRE sequences, and can be reduced by using TSE sequences and parallel imaging techniques.Conclusion: For the intrinsically higher SNR at 3 T, we need to pay a price: a higher prevalence of artifacts. In this presentation, we have presented an over-view of the different types of artifacts, and we have suggested ways to avoid or decrease them.

C-752 Functional imaging with MR T1 contrast: A feasibility study with blood-pool contrast agent A. Majos1, P. Bogorodzki2, E. Piatkowska-Janko2, T. Wolak2, R. Kurjata2, L. Stefanczyk1; 1Lodz/PL, 2 Warsaw/PL (egnys@poczta.onet.pl)

Purpose: The standard method for fMRI, using the BOLD effect suffers from poor image quality due to signal dropout near susceptibility boundaries. Additionally, single-shot EPI- typically used causes image distortion and blurring. The aim of this study was to proof the concept of using blood-pool agent T1 contrast as a new functional imaging method and to compare activation maps with BOLD T2* technique.Methods and Materials: For each of the 10 healthy subjects, two functional ‘runs’ were acquired on 1.5 T scanner with block type stimuli with 15 finger tapings in 30 s length ‘on’ periods. Reference run with typical T2* EPI sequence (TR=3 s/TE=40 ms/FA=90 deg) as well as the second run with T1 sensitive 3D GR sequence (TR=8.5 ms/TE=3.14 ms/FA=10 deg) after intravenous administration (0.03 mmol/kg) of VASOVIST (Schering) were carried out. SPM5 software was used for statistical analysis.Results: Maximum activation of run1 (peak Z score=5.5) was localized in the left postcentral gyrus. The cluster (size 3449 voxels, threshold p 0.001) was spread over Brodmann area 1 (BA1) -1.59% of volume size, BA2-4.87%, BA3-10.44%, BA4=10.44%, BA6-7.94%, BA40-3.77%. Data of run 2 did not show any statisti-cally significant results, but for 6 subjects from 10 statistically significant activation foci (peak Z score ranged from 3.78 down to 2.5) smaller than (average value 400 voxels), but overlapping with those in run1 were found.Conclusion: A new functional imaging method with smaller image artifacts was proposed and verified. The blood-pool agents with high spatial resolution T1 se-quence are promising perspective for fMRI examinations in nervous areas sensitive to susceptibility artefacts.

C-753 Fifteen years follow-up with MRI in very low birth-weight children C. Wang, O. Flodmark, P.-O. Gaddlin, P.-O. Gaddlin; Stockholm/SE (chen.wang@karolinska.se)

Purpose: To present the results of cerebral MRI studies on a population-based group of children with very low birth-weight (VLBW 1500 gram) and related to the results of their ultrasonography (US) at earlier postnatal time.Methods and Materials: The study was designed to include all VLBW-children born alive in a period between 1987-02-01 and 1988-04-30 in southeast Sweden. Totally, 86 children, 47 boys and 39 girls were included with an average gestation age 30.6 2.5 weeks and average birth weight 1191 216 grams. 60 VLBW-children were examined with MRI at 15 years of age, with imaging protocol consisting of T1, T2, T2-FLAIR and T1-IR images. Infantile US reports of these children archived in the local hospitals were reviewed.Results: 30% (18/60) patients had abnormal MRI findings, including astrogliosis, loss of deep cerebral white matter and porencephaly. One patient showed cortical malformation. US records were found in 85 VLBW-children, 38.8% (33/85) with records of US abnormalities at least with one examinations, 54.5% (18/33) were found within the first week of life and 90.9% (30/33) were found during the newborn period. 59 children had both MRI and early US records. 26 had abnormalities with US and 17 with MRI, but only 10 had abnormalities with both US and MRI.Conclusion: In this population-based VLBW-children group, 38.8% had US abnor-malities during infancy and 30% with MRI changes at 15 years. Only 16.9% subjects had persistent abnormalities with both infantile US and follow-up MRI.

C-754 Nociception in men and women using 3 Tesla MR spectroscopy P. Schmidt, A. Gussew, R. Rzanny, J.R. Reichenbach, W.A. Kaiser; Jena/DE (drpschmidt@med.uni-jena.de)

Purpose: The purpose of this study was to asses whether there are detectable differences in the change of neurotransmitter concentrations in men and woman during nociception by means of (1)H MRS.Methods and Materials: 6 healthy right handed subjects (3 men, 3 woman, mean age 22.5 years) underwent cerebral (1)H-CSI-MR spectroscopy (PRESS, TR/TE=2000/30 ms, SL 10 mm, FOV 240x160 mm2, TA=9.5 min) using a 3 Tesla scanner (Trio, Siemens) before and during induced ischemia of the left lower arm. Ischemia was induced by the inflation of an air cuff placed at the left upper arm until the cuff pressure exceeded the systolic blood pressure of the subject. The glutamate concentration was measured on both sides of the cerebrum in the area of the thalamus, the rostral insular cortex and the anterior cingula cortex. The glutamate concentrations in the areas were calculated with the LC-model.Results: There were no statistically significant changes of the glutamate concen-tration in the male and female subgroups in all sampled areas of the cerebrum, although strong interindividual differences were detected. This result maybe due to a glutamate concentration compensation-mechanism during the relatively long acquisition time, but could also be due to the small number of subjects included in the study. Studying a larger group of individuals with the use of a short acquisition time could resolve significant differences in the nocipetion between the male and female subgroups.Conclusion: Cerebral changes of the glutamate concentration during nociception are detectable by (1)H-MRS in men and woman.

C-755 Elevated choline/cratine ratio in central nervous system arterial infarction: Frequency, timing, extent and the effect of echo time M.B. Vardar, G. Akansel, N. Inan, H.T. Sarisoy, A.S. Arslan, E. Ciftci, A. Demirci; Kocaeli/TR (gakansel@superonline.com)

Purpose: To evaluate the frequency, timing and extent of the elevation of choline/creatine ratio on MRS in patients with arterial infarcts and determine if MRS pattern in subacute infarcts is sufficiently different from that of a neoplasm.Methods and Materials: Twenty nine patients with arterial infarcts were evaluated with single voxel proton MRS using PRESS sequence at TE 136 and 272, between 6 hours and 93 days after the onset of symptoms. Seventeen normal volunteers served as controls. Choline/creatine, N-acetyl aspartate/creatine and lactate/cre-atine ratios were calculated. Differences between data points were measured using Mann-Whitney U test. Correlation between metabolite ratios and infarct stage was tested using Pearson’s test. Differences between measurements made using dif-ferent echo times were tested with Wilcoxon’s test.Results: Choline/creatine ratio exceeded 1.8 in 38% of the spectra at TE 136 and 24% of the spectra at TE 272. Only choline/creatine ratios correlated significantly with infarct stage. Correlation was better at TE 272 (p .01) than at TE 136 (p .05). Cho/Cr was significantly (p .05) greater in patients in late subacute and chronic stages than controls. In the subacute stage, lactate/creatine was significantly greater at TE 272 than TE 136 (p .05).Conclusion: Significant elevations occur in Cho/Cr subacute during late subacute and chronic stages of arterial CNS infarction. MRS alone may be misleading in dif-ferentiating subacute infarct from tumor when choline/creatine ratio is the criterion. Echo time of MRS may significantly alter metabolite ratios measured.

C-756 Listening to Mozart piano concert K. 491 in C-minor, part II Larghetto facilitates a visually driven complex motor task during bold fMRI in females, but not in males G. Akansel, B. Gulleroglu, H.T. Sarisoy, Y. Anik, A.S. Arslan, A. Demirci; Kocaeli/TR (gakansel@superonline.com)

Purpose: To evaluate the effects of classical music and noise on the BOLD fMRI activation patterns in females and males.Methods and Materials: 24 volunteers (12 females, 12 males, range: 19-39, mean: 29) were evaluated. During the active blocks, the subjects were shown numbers from 1 to 4 and were asked to oppose their thumbs with predetermined fingers for each number shown. Three sets of data were acquired; the first with scanner noise alone, the second with the subject listening to a 93 decibel vacuum cleaner noise, and the third set with 73 decibel classical music (Wolfgang Amadeus Mozart Piano Concert K. 491 in C-minor). Active pixels in different brain regions were counted by two radiologists and the average number for each region was recorded.

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Results: Significantly greater number of pixels were activated while listening to music in males than females in the right cerebellar hemisphere and right sensory cortex. In females, significant decreases in the amount of activation were found in the right cerebellar hemisphere from basal to additional music, left cerebellar hemisphere from basal to additional music, right sensory cortex from basal to additional music and left sensory cortex from basal to additional music. In males, no significant change was noted for any of the locations between any two of the test conditions.Conclusion: The “Mozart effect” as evidenced by facilitation of a visually driven complex motor task is demonstrable by fMRI using the above described design in females, but not in males.

C-757 Fusion of MRI and SPECT images as the method of planning spectroscopy in order to assess hot spots of brain tumors P. Grzelak, A. Majos, M. Górska-Chrzastek, J. Kusmierek, M. Olszycki, W. Gajewicz, L. Stefanczyk; Lodz/PL (piotr.grzelak@insrad.am.lodz.pl)

Purpose: Most essential modalities for morphological imaging of the brain are mag-netic resonance imaging (MRI) and, for metabolic imaging, single photon emission tomography (SPECT). By using image fusion of different modalities, the location of areas exhibiting functional changes can be more easily identified. This study compares the results of iodine-131-alpha-methyl-tyrosine SPECT (IMT-SPECT) with MRI in brain tumor detection. We used fusion images as the method of planning 1H-MRS and verifying the metabolic content of the regions.Methods and Materials: We investigated pre-therapeutically 41 patients with the clinical diagnosis of brain tumor: 15 primary and 26 recurrent tumors. IMT-SPECT and MRI were performed during the same week. 131-IMT is a marker of brain tu-mors. Fusion of the images was done in a three-dimensional technique using a PC work-station; the technique was based on statistical analysis of three-dimensional distribution of the voxels, using maximization of the statistical resemblance. Regions of the highest accumulation of the 131-IMT were found by using subtraction method. In the result these areas were then subject to 1H-MRS.Results: In all patients with recurrent tumor suspected and in 10 patients with primary tumor the MRI images demonstrated presence of polymorphic lesions and planning the 1H-MRS was difficult. The concentration of IMT within brain tumors was heterogeneous and the delineation of the highest metabolic area was possible. This area allowed planning H1-MRS. In 36 patients a good quality of 1H-MRS spectra were obtained.Conclusion: The fusion images optimize selection of a site for spectroscopy investigation in recurrent tumors.

C-758 Volumetric measurement of human red nucleus with 3D fast spin echo T2-weighted sequence MR imaging E. Rahimian1, M.R. Tahsini1, A. Vossough2, B. Ohadi1; 1Tehran/IR, 2Boston, MA/US (info@elhamrahimian.com)

Purpose: The human red nuclei are a pair of globular, iron-containing structures located in the mid brain. Our purpose was to assess the feasibility of red nucleus volume measurements by three-dimensional fast spin-echo MRI sequence in healthy volunteers to establish a normative baseline in order to assess its volume changes during the aging process and neurodegenerative disorders.Methods and Materials: 20 healthy volunteers, 20 to 40 years old (10 men, age 27 3.27 years (mean standard deviation) and 10 women, age 28.1 4.7 years) were examined with a 3D FSE T2-weighted MR sequence using a 1.5-Tesla magnet.

The scanning parameters were 2800/80/1 (repetition time/echo time/number of excitations), acquisition matrix size of 192 x 256, and a slice thickness of 1.5 mm. The 3D acquired images were transferred to an offline dedicated workstation and red nucleus volumes were manually quantified.Results: The volume of the red nuclei were 265.28 45.07 mm3/259.87 48.68 mm3 (right/left) in men and 238.24 36.96 mm3/242.59 32.01 mm3 (right/left) in women. There was no statistically significant difference between volume of right and left nuclei in either gender (P 0.05). Also, the measured red nucleus volumes showed no statistically significant difference between men and women (P 0.05). The volume of the red nuclei was relatively constant between the ages of 20 to 40 years in both genders.Conclusion: To our knowledge, no study to date has measured red nucleus vol-umes for providing normative data. We attempted to define a feasible quantitative method for red nucleus volumetric measurements.

C-759 Prevalence of subependymal giant cell tumors in a large cohort of patients with tuberous sclerosis complex and preliminary results of a non-invasive treatment M.E.A.P. Adriaensen1, D.A.C. Duyndam2, B.A. Zonnenberg3, M. Prokop3; 1Amersfoort/NL, 2Amsterdam/NL, 3Utrecht/NL (miraude@gmail.com)

Purpose: To investigate the prevalence of subependymal giant cell tumors (SGCT) in patients with tuberous sclerosis complex (TSC) and to report our first experience with rapamycine for treatment of SGCT.Methods and Materials: Our institution, a referral center for TSC, followed 285 individuals. We included all TSC-patients who had received a contrast-enhanced CT scan of the brain. The most recent scan was evaluated for SGCT and the pres-ence of hydrocephalus. We used two sample t-test and ²-test. In addition, two patients with symptomatic SGCT were experimentally treated with rapamycine. We measured tumor size before and 4-6 months after beginning treatment.Results: CT showed radiological evidence of SGCT in 43 out of 214 included TSC-patients (20%). SGCT was found in 23 of 105 men (22%) and 20 of 109 women (18%; p=0.52). Patients with SGCT (mean, 31 years; range, 16 to 58 years) were on average younger than patients without SGCT (mean, 37 years; range, 10 to 72 years; p=0.007). Maximum tumor diameter in the axial plane varied from 4 mm to 29 mm (mean, 11.4 mm). Nine patients had bilateral SGCT (7 men, 2 women; p=0.10). Hydrocephalus was present in 6 of the 43 patients (14%). In the two patients (three SGCT) treated with rapamycine, the enhancing part of all tumors showed a decrease in maximum axial diameter.Conclusion: CT demonstrated radiological evidence of subependymal giant cell tumors in 20% of TSC-patients. Complicating hydrocephalus was seen in 14% of SGCT-patients. In our initial patients treated with rapamycine, tumor regression could be shown.

C-760 Detection and characterization of intracranial aneurysms with volume CT digital subtraction angiography: Comparison with conventional DSA and CTA F. Lv1, T. Luo1, J. Liao2, Y. Shen2, K. Chen2, J. Li2; 1Chongqing/CN, 2Beijing/CN

Purpose: To evaluate the usability of Volume CT Digital Subtraction Angiography (VCTDSA) in the detection and characterization of intracranial aneurysms through comparing with conventional DSA and CTA.Methods and Materials: Thirty-two patients with intracranial aneurysms under-went 64-slice CT (GE, LightSpeed VCT) and conventional DSA examination. CT examination included non-enhanced helical scan (80 kV) and contrast-enhanced helical scan (120 kV) at the same region for digital subtraction (bone removal). The contrast-enhanced series was used for conventional CTA and the subtrac-tion images from the two series were used for VCTDSA. Both conventional CTA and VCTDSA were reformatted and displayed with 3D volume rendering (3D VR) and compared with conventional DSA for the detection and characterization of intracranial aneurysms.Results: 35 aneurysms were found with conventional DSA and 36 aneurysms were found with conventional CTA. In addition, conventional CTA was better than conventional DSA in depicting the shape, direction and location of aneurysms (34/36). But conventional CTA was often useless to some intracranial aneurysms, which are adjacent to bony structure. A total 39 aneurysms were found with VCTDSA that could remove bony structure fast and clear and it was superior to conventional DSA and conventional CTA in all 39 aneurysms.Conclusion: VCTDSA is a non-invasive diagnostic method and can remove bony structure that interferes with the detection of intracranial aneurysms. Dual energy scan (80 kV/120 kV) is good for bone removal and radiation dose reduction. VCTDSA is superior to conventional DSA and conventional CTA in the detection and characterization of intracranial aneurysms.

C-761 Autopsy imaging (Ai), a new imaging horizon in pathology by using multidetector computed tomography (MDCT) S. Yamamoto, K. Motoori, R. Shimofusa, T. Horikosi, T. Kazama; Chiba/JP (seikichi@faculty.chiba-u.jp)

Purpose: In recent years, a new procedure termed “Autopsy imaging (Ai)” has been developed as an application in the field of pathology in Japan. We have been performing postmortem computed tomography (PMCT) study using MDCT prior to autopsy since last year and systematized CT examination prior to autopsy at our hospital. We explain this process and methods.Methods and Materials: We did performed the above procedures with 1 mm slice thickness and an imaging range from the head to a knee, and performed 3D imaging by using MDCT.

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Results: First we reviewed the major findings with a monitor and made a report prior to the autopsy. When new evidence was found on CT imaging, the pathological method may change because of this information. It is rare to perform dissection of the head by normal dissection in Japan. Therefore, using this laboratory method to confirm that the head does not have a lesion beforehand is useful. A macro-specimen and 3D image correlation is possible.Conclusion: The following three roles of Ai are considered in emergency medicine, forensic medicine and pathology: 1) screening to detect the cause of death, 2) screening to select cases in which autopsy is required, and 3) use as an autopsy guideline. To anatomize that accurately preserves lesion specifies cause of death, it is useful to perform a CT or MRI before autopsy.

C-762 Postmortem study of patients with dementia: Radiological and histological findings in the hippocampus T. Cabada, C. Echávarri, C. Caballero, T. Tuñón, C. Bacaicoa, I. Insausti; Pamplona/ES (tcabadag@cfnavarra.es)

Purpose: To describe the findings in the hippocampus in MRI studies of post-mortem brains of patients with dementia and its relationship with the histological diagnosis.Methods and Materials: 56 brains were scanned in a 1.5 T MRI unit (Siemens Avanto). 35 were patients with dementia from the brain bank of Navarra and the other 21 were controls from autopsy studies. The signal intensity and hippocampus volume were recorded in each patient. These measures were made in a T2-weighted flair sequence (TI=2200/TR=6000/TE=353). Data of leukoaraiosis, infarcts and hemorrhage were assessed in MRI and pathological analysis. Vascular risk factors, age and gender were obtained from clinical history.Results: Six brains were excluded (1 lobar hematoma, 2 acute ischemia and 3 chronic isquemia in temporal lobe). The anatomopathological diagnosis was: 12 Alzheimer disease (AD), 3 vascular dementia (VD), 12 mixed dementia and 8 other causes (Creutzfeldt-Jakob disease, Huntngton corea, frontotemporal dementia, Lewy bodies disease and progressive supranuclear paralysis). A statistically signifi-cant difference of the hippocampal volume was found between controls (31.30 cm3) and patients with dementia and between AD patients (21.90 cm3) and patients with dementia no AD (26.84 cm3). There was a significant, but weak, correlation between hippocampus signal intensity and volume. Also the signal intensity presented a significant difference between controls and patients with dementia.Conclusion: The hippocampal volume is a good marker of Alzheimer disease in postmortem brain. The hippocampal volume and signal intensity can help to dif-ferentiate between patients with and without dementia.

C-763 Evaluation of CT perfusion parameters in thrombolytic therapy (intravenous rt-PA injection) for acute cerebral infarction K. Yuba, Y. Yoshimoto, D. Yamana, H. Ohkawa, K. Wada, K. Ono, K. Suzuki; Meguro-ku, Tokyo/JP (mishuku-CT@mishuku.gr.jp)

Purpose: At our hospital, a CT Perfusion study (CTP) is performed before the intravenous injection of the thrombolytic agent rt-PA (alteplase) in patients with acute cerebral infarction (within 3 hours after the onset of symptoms). In the present study, the usefulness of the CTP parameters CBF, CBV, and MTT for assessing the patient’s prognosis was evaluated.Methods and Materials: The subjects were 42 patients (mean age: 75.2 years) who had undergone CTP before the intravenous injection of rt-PA. CBF, CBV, and MTT were measured in the left and right MCA, and the patients were classified into two groups based on their NIH Stroke Scale (NIHSS) scores: those with scores of 5 points or more (19 patients) and those with scores of 4 points or less (23 patients). The two groups were then compared using the Mann-Whitney test.Results: A significant difference was seen in CBV: 2.9 4 for NIHSS scores of 5 or more and 1.6 0.48 for NIHSS scores of 4 or less (p 0.05). For CBF, the results were 15.4 6.9 for NIHSS scores of 5 or more and 12.6 8.9 for NIHSS scores of 4 or less, and for MTT, 10.0 2.6 for NIHSS scores of 5 or more and 11.2 3.1 for NIHSS scores of 4 or less (no significant difference for either parameter). The therapeutic effect could be estimated by comparing CBV values between healthy and affected areas.Conclusion: CBV is a useful parameter in CTP studies to evaluate the therapeutic effect of intravenous rt-PA injection.

C-764 Correlation of PET hypo- and hypermetabolism with surgical outcome in refractory epilepsy R. Talanow, G. Wu; Cleveland, OH/US (roland@talanow.info)

Purpose: The value of PET imaging in patients with refractory epilepsy who dem-onstrate frequent spiking activity on EEG and ictal activity shortly after injection of FDG is unknown. The purpose of this study was to evaluate PET findings in this population in relation to surgical outcome.Methods and Materials: 294 patients (142 female, 152 male; age 1 day-64 years) with refractory epilepsy underwent PET imaging for presurgical workup for seizure focus removal. Surgical outcome was measured as seizure free, improved and failed. EEG was classified as true interictal (normal), interictal with frequent spikes and ictal (clinical seizure present). PET findings were defined as hypermetabolism, normal and hypometabolism in the resected area.Results: 260 (88%) patients had true interictal PET imaging, 14 (5%) ictal and 20 (7%) had interictal but frequent spiking activity. 95% with true interictal PET dem-onstrated hypometabolism, with 85% seizure free or improved. 5% demonstrated normal metabolism with 83% seizure free. 9 (45%) patients with interictal but frequent spiking activity demonstrated hypermetabolism, 9 (45%) hypometabolism and 2 (10%) normal metabolism. 6 (43%) showed hypermetabolism and 8 (57%) hypometabolism with ictal PET. 92% with frequent interictal spikes or ictal EEG with hypermetabolism were seizure free. Patients with frequent spikes or ictal EEG with hypometabolism and patients with normal EEG had a 100% seizure free rate.Conclusion: Both PET hypermetabolism and hypometabolism in patients with frequent spiking activity and ictal state correlated well with surgical outcome. Surgical outcome in refractory epilepsy can be predicted by PET imaging even in patients with frequent seizures or spiking activity.

C-765 Investigation of optimal volume rendering image in brain surface with high resolution three-dimensional MRI I. Kiriyama, H. Miki, Y. Hiratsuka, K. Kikuchi, T. Mochizuki; Toon City/JP (ikukosan@m.ehime-u.ac.jp)

Purpose: To investigate optimal volume rendering (VR) image for brain surface with high resolution three-dimensional (HR-3D) MRI. To evaluate usefulness of optimal VR image in the pre-surgical planning of glioma.Methods and Materials: Five patients with glioma were examined with 1.5 T MRI. 3D-MRI was performed by SPGR with a matrix of 512, a slab of 0.8x256 mm, TR/TE/FA;25/2.5/20, and ASSET factor 2.0. VR images were generated on a worksta-tion. The following items were investigated about VR image: 1. color or black-white shading; 2. type of opacity curve; 3. lower and higher thresholds of opacity curve; and 4. maximum opacity: opacity of higher threshold is assumed to be maximum opacity. In addition, utility of the VR image generated basing the above investiga-tions in the pre-surgical planning was examined.Results: The following results were optimal for VR image of brain surface: 1. black-white shading; 2. linear type: the opacity of the voxel with a value that is between lower and higher thresholds increases linear within the range from transparent to maximum opacity; 3. the lower threshold of the opacity curve was 0 and the higher threshold of that was twice the maximum value of white matter; and 4. maximum opacity was low value (0.3). The contrast between normal cortex and tumor were better, and it was easy to identify the sulci and gyri when maximum opacity was low value (0.3).Conclusion: VR image generated from HR-3D MRI data with lower maximum opacity of the brain surface is useful for pre-surgical planning.

C-766 Diffusion-weighted images in the evaluation of meningiomas: Radiopathologic correlation T. Cabada, I. Insausti, C. Caballero, T. Tuñón, C. Bacaicoa, J. Olier; Pamplona/ES (tcabadag@cfnavarra.es)

Purpose: To study the meningiomas appearance on diffusion-weighted images and its correlation with histopathologic findings.Methods and Materials: Patients with meningiomas operated in the last two years in our hospital were prospectively included in this series. All patients were studied in a 1.5 T MR (Siemens Avanto) before surgical intervention, including diffusion-weighted images (DWI). The signal intensity (SI) of the meningiomas was assessed on T2-weighted images, DWI (b=1000) and ADC maps, within the tumor and in the white-matter of the parietal lobe as reference. All tumors were completely resected. In the histopathologic examination the cellularity, proliferation rate, histologic grade, and brain invasion were analysed.

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Results: 30 meningiomas in 28 patients (12 women and 6 men) between 32 and 84 years (average age 56) were studied. 21 meningiomas were World Hearth Organization (WHO) grade I and 7 were atypical (WHO grade II). Meningiomas showed similar or less SI to the white-matter in 17/30 and slightly higher in the remainder. The SI in the DWI (b=1000) was associated with the SI in the T2-weighted images, but not with the SI in the ADC maps, interpreted as a T2 shining through artifact. The SI in the ADC map had a statistically significant association with tumor cellularity in the pathological analysis but not with the proliferation rate or the WHO histologic grade.Conclusion: Meningiomas show a moderate restricted diffusion. The SI in the ADC map is associated with the cellularity tumor but it is not useful to predict the WHO histologic grade.

C-767 Evaluation of subtracted cerebral 3D-CT angiography at lower tube voltage T. Gomi1, M. Hasegawa1, A. Kato1, M. Nagamoto1, E. Kohda1, M. Tsunoo2, H. Terada2; 1Tokyo-Meguro/JP, 2Chiba/JP (gomi@oha.toho-u.ac.jp)

Purpose: It is known that the CT value of contrast media is elevated at lower tube voltages, but at the same time, the CT value of the skull is elevated. The purpose of this study was to evaluate the efficacy of subtracted cerebral CT angiography at lower tube voltages.Methods and Materials: Fifteen patients known or suspected with intracranial aneurysm or cerebral infarction were enrolled. The patients were divided into three groups by flow rate and tube voltage, Group A 4 ml/sec (Iopamidol 370 mgI/ml), 120 kVp and 150 mAs, group B 4 ml/sec, 80 kVp and 300 mAs, and group C 3 ml/sec, 80 kVp and 300 mAs. The fixed duration of contrast media injection was 15 seconds, and 30 ml of saline was injected after contrast media injection. Nonenhanced volume data was subtracted from the enhanced volume data. The CT value of the internal carotid artery and the signal-to-noise ratio (SNR) was measured. Two radiologists estimated qualitative evaluation of arterial contrast enhancement and the visibility of small vessels. Statistical analysis was evaluated using Student’s t-test.Results: The CT value of the internal carotid artery was significantly higher in group B than in group A (p 0.05), but no statistical difference was present between groups A and C. There were no statistically significant differences in the measurements of SNR among all of the groups. Qualitative evaluation showed a significant difference between groups A and B (p 0.05).Conclusion: For subtracted cerebral CT angiography, superior image quality was seen in 80 kVp. These results suggest that using lower tube voltages can reduce flow rate.

C-768 The effect of ethyl alcohol on the central nervous (CNS) system determined with the HMRS technique A. Urbanik, B. Sobiecka, J. Kozub; Krakow/PL (aurbanik@mp.pl)

Purpose: The aim was to assess the effect of ethyl alcohol on the CNS with the HMRS technique.Methods and Materials: The research, performed with the HMRS Signa Excite 1.5 T (GEMS) system, covered 14 healthy male volunteers aged 22 to 55 (aver. 34.8), occasionally consuming alcohol. The experiment consisted of four sessions in different time intervals. The volunteers were examined before the first meal of the day in the first session prior to drinking alcohol (150 ml of vodka) and after 0.5 h, 1 h, 2 h.Results: We notice after drinking alkohol: 1.2 ppm (Eth) peak in all the locations of the brain, increase in Lip/Cr (up to 53%), Lac/Cr (up to 76%), Glc1/Cr (up to 26%) and Glc2/Cr (up to 24%), decrease in GABA/Cr (up to 23%), Glx1/Cr (up to 14%), Glc1/Cr (up to 37%), Glx2/Cr (up to 27%), all in the following sessions. No significant changes were noticed related to the proportions of NAA/Cr, Cho/Cr, mI/Cr in the examined locations.Conclusion: HMRS is a non-invasive, neurochemical method, which enables as-sessment of the effect of ethyl alcohol on the CNS. On the basis of the conducted research, the following were found out: 1. Presence of ethyl alcohol in cerebral tissue on the basis of the visible peak 1.2 ppm, absent in the spectra from the first session prior to drinking alcohol. 2. The changes in maintaining the relative proportions in concentrations, especially for Lip/Cr, Lac/Cr, Glc/Cr, GABA/Cr and Glx/Cr.

C-769 The use of DYNA-CT in neuroradiology A. Urbanik, T. Turski, T.J. Popiela, P. Brzegowy; Krakow/PL (aurbanik@mp.pl)

Purpose: DynaCT enables to perform CT-like images with the use of C-arm angi-ography system. The study evaluates the value of DynaCT option for neuroradiology and interventional neuroradiology.Methods and Materials: A group of 118 patients were qualified to DynaCT per-formed using single plane Axiom Artis (Siemens) DSA system. The parameters of the examination were: 512x512 image matrix, 20 sec rotation time, 0.4 degree increment, 220 degree rotation angle, approximately 15-30 frames/seconds, and number of projections - 538.Results: In the patients with highly vascularized tumors, DynaCT allowed accurate localization of the lesions for planning neurosurgical procedure. In all cases where cerebral bleeding occurred there was possibility to visualize this complication. The method was helpful at the final stage embolisation of brain aneurysms and AVMs. When the clinical condition of the patient deteriorated, the use of DynaCT performed during the procedure eliminated the need for transporting the patient for CT lab and allowed immediately administered treatment. DynaCT allowed for better visualisation than in conventional DSA, intracranial coils and stents locali-sation, particularly its structures and their relationships to the arterial wall as well as aneurysmal sac.Conclusion: DynaCT is supplementing DSA neuroangiography by allowing spatial localization of brain vascular pathologies. During neurointervention procedures ensures that the coils or stents are placed correctly. Additionally, it may be used instead of standard CT of the head as a control examination to detect suspect haemorrhage as a complication of above procedures, which reduce the need for transporting patients to CT labs.

C-770 The appearance of decussation of superior cerebellar peduncle in DTI Y. Dou1, H. Han2, S. Guo1, Y. Feng2, J. Pi3; 1Lanzhou/CN, 2Peking/CN, 3Changzhi/CN (dydouyu621@126.com)

Purpose: To summarize the appearance of decussation of superior cerebellar peduncle on MR diffusion tensor imaging (DTI) with different parameter of scan-ning and reconstruction.Methods and Materials: Ten healthy volunteers were examined on SIEMENS 3.0 T MRI DTI (b=0, 1000 s/ mm2), post processing was made in SIEMENS Leonardo workstation using SIEMENS Standar 6 dirs software to reconstruct the white matter fibers with different fractional anisotropy (FA) threshold value (0.04-0.12), angle threshold value (20°-89°) and voxel size (1.2 mm×1.2 mm×3 mm-1.6 mm×1.6 mm×5 mm).Results: There were five kinds of MR fiber tracking appearances at the level of decussation of superior cerebellar peduncle (SCP). The fiber crossed to the op-posite red nucleus in anterior-posterior and superior-inferior styles. There were significant differences between the number of crossing fiber with FA 0.06 and those with FA 0.08 (p 0.05). There were significant differences between the number of crossing fiber with angle 60° and those with angle 80° (p 0.05). There were no significant differences between the number of crossing fiber at voxel sizes (p 0.05). No crossing fiber demonstrated in all cases. The single main bundle fiber after decussation was found in FA 0.10. All cases showed missing fiber sign, which mainly locate in the center of the decussation.Conclusion: DTI fiber tracking can show the descussation of SCP in most health volunteers with five typical appearances. The lesser FA 0.08 and the bigger angle 80° show the crossing fiber of SCP was recommended for manifestation.

C-771 Optimisation of hypercapnia paradigms using cued breath holding at 1.5 T and 3.0 T D. Bos, A. van der Lugt, M. Smits; Rotterdam/NL (marion.smits@erasmusmc.nl)

Purpose: Hypercapnia may be used to noninvasively measure the brain’s global blood oxygenation level dependent (BOLD) responsivity, which can be induced with breath-holding. The purpose of this study was to determine the minimum breath-hold duration for the BOLD signal change to become detectable, both at 1.5 T and 3.0 T.Methods and Materials: In each of 6 healthy volunteers, 5 experiments were per-formed at 1.5 T and 3.0 T, each experiment consisting of cycles of breath-holding alternated with periods (40s) of normal breathing. Breath-hold durations of 5s, 10s, 15s, 20s and 30s were tested. A BOLD-sensitive T2*w gradient-echo EPI sequence was used. Data analysis consisted of spatial pre-processing and of single subject and first-level group analyses.

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Results: Subjects were aged 19-25 years, 3 male, all right-handed. All but 1 subject showed significant BOLD signal changes for 15s, 20s and 30s breath-hold dura-tions at both field strengths, and for the 10s duration at 3.0 T. For the 5s duration, no BOLD signal change was seen in any of the subjects. The largest BOLD signal change was observed in the deep grey nuclei, followed by the cortical grey matter in the frontal and parietal lobes. BOLD signal change at 3.0 T was more extensive than at 1.5 T for all breath-hold durations.Conclusion: A 10s (3.0 T) to 15s (1.5 T) breath-hold duration seems sufficient for detection of BOLD signal changes induced by hypercapnia. This simple experiment can easily be incorporated in BOLD fMRI experiments to obtain a baseline measure of BOLD responsivity, which would be of great value in certain populations.

C-772 Multidetector-row CT angiography for evaluation of arterial dissection of the anterior cerebral artery I. Matsuda, I. Shirouzu, S. Amemiya, J. Kazaoka, H. Akai, M. Noda, T. Machida; Tokyo/JP

Purpose: Arterial dissection of the anterior cerebral artery (ACA) is a rare entity which may cause cerebral infarction and subarachnoidal hemorrhage. The purpose of the present study is to evaluate the usefulness of multidetector-row CT angiog-raphy (CTA) in patients with ACA dissection retrospectively.Methods and Materials: Imaging findings of 29 CTA studies of 7 patients with ACA dissection which were diagnosed with conventional angiography during a 6-year period were retrospectively evaluated. Follow-up CTA images were also reviewed to evaluate the long term changes of ACA dissection lesions.Results: The mean patient age was 56 10.7 years (range: 47-76 years) at the onset. Cerebral infarction was diagnosed with magnetic resonance imaging and magnetic resonance angiography in all cases. Six patients underwent CTA in acute phase. Those CTA studies showed double lumen sign in 2 cases, tapering and narrowing with peripheral hyperdensity in 2, dilation with stenosis in 1 and stenosis in 1. Follow-up CTA images illustrated subsequent progression of steno-sis. Although the ACA dissection lesions have resolved gradually, their irregular luminal surface remained.Conclusion: CTA is feasible to demonstrate the ACA dissection lesions in acute phase. Because CTA is less invasive than angiography, it is also useful to evaluate the chronic phase ACA dissection lesions.

C-773 Fetal ventriculomegaly: MRI investigation T. Stosic-Opincal, V. Peric, S. Lavrnic, M. Gavrilov, R. Milenkovic; Belgrade/RS (tanja.stosic@kcs.ac.yu)

Purpose: To determine the frequency and type of cases in which fetal magnetic resonance imaging (MRI) provides additional clinically relevant information in fetuses with ventriculomegaly diagnosed on routine ultrasound examination.Methods and Materials: Twenty seven cases presenting with different degrees of cerebral ventriculomegaly depicted by sonography underwent MRI investigation. The mean gestational age of fetuses was 31.6 weeks.Results: Fetal MRI confirmed the sonographic diagnosis in 25 of 27 cases, revealed additional findings in 22 of 25 cases. Two patients with the diagnosis of isolated ventriculomegaly were found on MRI to have ventricles that measured within the range of normal ( 10 mm atrial diameter). In one of these cases, an arachnoid cyst was clearly visualized on MRI. In the marked ventriculomegaly group (17 cases), 4 cases of complete agenesis of the corpus callosum, 3 cases of intraventricular hemorrhage, 6 cases of polymicrogyria, 3 cases of pachygyria and 1 case of cranio-synostosis were detected. In the group of moderate ventriculomegaly (8 cases), 3 cases of partial agenesis of the corpus callosum, 2 cases of porencephaly, 3 cases of lizencephaly and three cases with kinked brainstem were detected.Conclusion: MRI is a useful additional examination in fetuses with ventriculomegaly, especially in visualizing associated anomalies, such as intraventricular hemorrhage, porencephaly, callosal dysgenesis, and cortical migrational abnormalities.

C-774 The connection between the auditory center of bilateral temporal lobes: A BOLD fMRI and tractography study Z. Wang, M. Chen, H. Song, C. Zhou; Beijing/CN (arthurz.wang@gmail.com)

Purpose: To assess whether the connection between the auditory centers of both temporal lobes by combining BOLD fMRI and Tractography based on the Diffusion Tensor Imaging (DTI).Methods and Materials: There were 10 volunteers in this study. They had no evidence of a brain disorder; and the bilateral auditory thresholds of all volunteers

were below the 25 Hz after pure-tone test using pure-tone audiometry. All volunteers underwent two fMRI studies given the mono-ear pure-tone stimulation and one DTI study with 13 directions, respectively. The type of experiment in this fMRI study was block design. In the activation periods, the 2000 Hz mono-ear pure tone stimulation lasting 30 seconds was given to each volunteer through each ear separately. In the base-line period, no pure-tone stimulation was given. All data were processed using Statistical Parametric Mapping (p 0.0001) and Volume-One softwares.Results: BOLD fMRI demonstrated the middle and posterior parts of Superior Temporal Gyrus (STG) in the contralateral hemisphere and Heschl’s Gyrus (HG) bilaterally was activated. Tractography showed the fibers rising from the STG of one side went directly to the HG of the other side through the posterior part of corpus callosum.Conclusion: Combining these two methods could demonstrate both the functional regions and the connections between them. The direct connection between both temporal auditory centers was found and the fibers were just from the STG of one side to the HG of the other side.

C-775 Long-term follow-up angiography of intracranial aneurysms treated with Cook detchable coil system J.M. Pumar, I. Lete, S. Baleato, M. Blanco, F. Vazquez, A. Garcia-Allut; Santiago de Compostela/ES (mrpumar@usc.es)

Purpose: The long-term durability of detachable coil embolization of cerebral aneurysms is still unknown. The purpose of this study was to evaluate the stability of anatomic occlusion of aneurysms treated with Cook detach coil system and assess the rate of recanalization and retreatment.Methods and Materials: 250 patients with 271 ruptured aneurysms treated with Cook detach system between January 1997 and September 2003, who subse-quently underwent follow-up angiography at 6 months, at 1 year and at 2 years were included in this study. We reviewed all the angiographic findings to determine the percentage of aneurysm occlusion. The morbidity and mortality associated with this technique was assessed.Results: Long-term follow-up angiograms (at 2 years) demonstrated complete oc-clusion in 75% of cases and subtotal occlusion in 25% of cases. Overall morbidity was calculated at 7.3%. Only 3.2% of the aneurysms required re-treatment. Only one patient displayed repeat or new subarachnoid hemorrhage.Conclusion: Late angiographic follow-up monitoring of aneurysms that have treated with “Cook” detach coil system demonstrated the stability and durability of the treatment.

C-776 Pattern of brain atrophy in elderly patients with depression revealed by voxel-based morphometry K. Egger, M. Schocke, E. Weiss, S. Auffinger, R. Esterhammer, G. Goebel, T. Walch, S. Mechtcheriakov, J. Marksteiner; Innsbruck/AT (karl.egger@i-med.ac.at)

Purpose: The aim of this study was to determine patterns of brain atrophy in elderly patients with depression and to explore possible correlation with neuropsychological parameters regarding cognitive impairment.Methods and Materials: 14 patients suffering from geriatric depression were compared to 20 age- and gender-matched healthy subjects using voxel-based morphometry based on T1-weighted FLASH 3D MRI images scanned on the same 1.5 T MRI scanner. Statistical parametric mapping software (SPM2) was used for image processing and statistical analyses. All subjects also underwent an extensive neuropsychological assessment.Results: VBM revealed a significant decrease of gray matter volume in the right amygdala, right hippocampus, and gyrus rectus bilaterally. Additionally, patients with geriatric depression showed significantly poorer performance in neuropsychological testing regarding cognitive impairment. After correction for multiple comparisons (p 0.003), the "constructional praxis recall" test was significantly different from control subjects. Correlation analysis with "constructional praxis recall" revealed significant (p 0.05) positive correlation with the hippocampus, putamen, nucl. caudatus, insula bilaterally and left thalamus.Conclusion: As no patient fulfilled clinical criteria for early dementia, and depres-sion is the first symptom of Alzheimer´s disease in about 30%, VBM could be a very helpful tool for the diagnosis of preclinical dementia and to predict the risk of elderly patients with depression converting into dementia.

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C-777 MR imaging of the normal/diseased abducens nerve S. Dekeyzer, M.M. Lemmerling, K. Verstraete; Gent/BE (sofiedekeyzer@skynet.be)

Learning Objectives: To illustrate the use of MRI in the diagnostic work-up of patients with abducens nerve paralysis of non-traumatic origin.Background: The nuclear portion of the abducens nerve is situated in the pons, anterior to the fourth ventricle. The nerve runs through the pons ventrally, having a long course in the prepontine cistern towards Dorello’s canal, where it pierces the dura. In the cavernous sinus, it runs lateral to the internal carotid artery. After passing the superior orbital fissure, it innervates the lateral rectus muscle. Patients with abducens nerve paralysis develop horizontal diplopia.Imaging Findings: Patients with abducens nerve paralysis are best imaged using T2WI of the brain and T1WI of the orbit. The cisternal course of the nerve is well studied using 0.5-1.0 mm thick 3D-T2WI. After gadolinium injection, axial and coro-nal T1WI are performed. Pending on the present problem additional sequences are considered: DWI (elderly), FLAIR (young patient), MRA, etc. A wide variety of lesions is seen and for each segment along the nerve’s course a limited differential diagnosis has to be considered. In the pons ischemia and tumor are more frequent, while men-ingeal disease (meningioma, infectious/carcinomatous meningitis) is predominantly seen in the prepontine cistern. In the cavernous sinus portion vascular, infectious or tumoral disease can be present. In the orbit a mass is most frequent.Conclusion: MRI is an excellent diagnostic tool in the work-up of patients with abducens nerve paralysis.

C-778 Central nervous system parasitic infections: Current trends due to immigration and world-wide travelling M. Navallas, A. Martãnez de Aragãn, R. Cano, L. Ibaãez, A. Ortiz de Mendivil, E. Salto; Madrid/ES (mnavallas@gmail.com)

Learning Objectives: To provide an in-depth review of neurological infections imported from tropical and subtropical regions in the world including their epide-miology and clinical manifestations. To illustrate CT and MR features and show key MR sequences that enable a correct diagnosis.Background: Infectious diseases of the CNS remain a challenging and increasing health problem, which is among the leading causes of death in underdeveloped countries.Procedure Details: 1. CT and MR images of CNS parasitic infections in immuno-competent patients: a) uncommon case of encephalomyelitis caused by schistosoma intercalatum, b) Hydatid disease (one case with spectacular destruction of lumbar spine, sacrum, coccyx and pelvis; another that affects cervical and dorsal spine with intracranial extension and maxillary sinus involvement, and the last one with spinal and paraspinal distribution), and c) Cysticercosis: numerous cases in its 4 different forms (parenchymal, meningeal, ventricular and mixed). 2. Other rare parasitic infections. 3. Most adequate MRI sequences to diagnose parasitic infections.Conclusion: Many parasitic infections were almost non-existent in industrialised countries until the boom in immigration and world-wide travelling. As they are potentially treatable diseases, its recognition is paramount to reach an early diagnosis that enables a prompt and effective treatment. The new functional MRI techniques (diffusion and perfusion weighted imaging, and spectroschopy) are useful, although the most efficient sequences to diagnose hydatid disease are steady state sequences.

C-779 Pituitary apoplexy: A review of imaging findings S.H. Liyanage, L.M. Vearncombe, J. Evanson; London/UK (sidliyanage@googlemail.com)

Learning Objectives: 1. To illustrate the spectrum of imaging findings in pituitary apoplexy. 2. To correlate the radiological findings with clinical presentation and pathology.Background: Pituitary apoplexy is a rare entity with a significant morbidity. We present a case series of 15 patients who were imaged in our institution. We describe the clinical presentation, pathology and imaging findings on both CT and MRI.Imaging Findings: 15 Patients with proven pituitary apoplexy were retrospectively reviewed. Only 1/15 was already known to have a pituitary lesion. Headache was the commonest presentation (13/15) but visual disturbance and cranial nerve palsies were often associated (12/15 and 6/15), a third nerve palsy being the most frequent

(6/15). All patients had an initial cranial CT followed by imaging with MRI ( contrast). Comparison was made of the CT and MRI findings. The degree of pituitary haemor-rhage was divided into 3 categories: no overt blood, faint blood and obvious blood. CT results were 8/15 (53%), 4/15 (27%) and 3/15 (20%), respectively. MRI results were 2/15 (13%), 9/15 (60%) and 4/15 (27%), respectively. Following intravenous gadolinium 2 enhancement patterns were observed on MRI: heterogenous 9/14 (64%) and homogenous 5/14 (36%). Local extension was quantified by observing: suprasellar extension 14/15 (93%), chiasmatic compression 13/15 (87%) and cavern-ous sinus involvement 1/15 (7%). Subsequent histological diagnoses were: adenoma 9/15, craniopharyngioma 1/15, hypophysitis 1/15 and necrotic tissue 4/15.Conclusion: This study suggests that standard CT can underestimate the extent of haemorrhage in pituitary apoplexy. Suprasellar extension and chiasmatic com-pression are common occurrences.

C-780 Cavernous sinus dural arteriovenous fistula: Shunt point, venous drainage and alternative treatment options Y. Sagara, H. Kiyosue, S. Tanoue, J. Kashiwagi, Y. Hori, M. Okahara, H. Mori; Oita/JP

Learning Objectives: To review imaging findings of cavernous sinus dural arterio-venous fistulas (DAVFs) on 2D and 3D-DSA and MR angiography. To demonstrate various venous drainage routes and simple and complex shunt types of cavernous sinus DAVFs. To discuss the treatment strategy based on natural history, venous drainage and shunt type.Background: Various treatment options have been performed for DAVFs. Recent developments in interventional techniques allow superselective venous emboliza-tion of fistulous pouch of cavernous sinus DAVFs with preserving normal outflow for some cases. Treatment strategy will be altered based on such technical devel-opments. We evaluated the normal venous anatomy of cavernous sinus by MR venography using 3D gradient echo sequence and reviewed it about the DAVF cases which we experienced in our department for past 8 years.Imaging Findings: We reviewed MR imaging of 70 cases (140 sides) about the normal venous anatomy of cavernous sinus by MR venography using 3D gradient echo sequence. Also 2D- and 3D- DSA or/and MR images were retrospectively reviewed in 58 cases of DAVFs which we experienced from 1999 to 2007. And treatment results of cavernous sinus DAVFs were evaluated based on drainage rout and shunt points including discussion of treatment strategy with literature review.Conclusion: The major teaching point of this exhibit is to know drainage routes, alternative treatments, and key findings to determine the treatment strategy of cavernous sinus DAVFs. The knowledge of this venous anatomy is crucial for diagnosis and intravascular treatment of DAVFs.

C-781 Imaging CNS complications after bone marrow transplantation T. Nishiguchi, K. Mochizuki, T. Nakane, Y. Inoue; Osaka/JP (tomokazu-n@med.osaka-cu.ac.jp)

Learning Objectives: 1. To illustrate the imaging spectrum of MRI and CT of neurologic complications after bone marrow transplantation (BMT). 2. To discuss the imaging techniques and diagnostic points of these lesions, focusing on the clinical status and time interval after treatment.Background: Central Nervous System (CNS) complications from BMT for various haematopoietic disorders are potentially devastating. The clinical and imaging mani-festations in the pre- and post-engraftment period were illustrated by a retrospective analysis of 100 consecutively treated patients (m:f=54:46; mean 47.2 y/o) with an allograft BMT between January 2004 and July 2007.Imaging Findings: Among 100 patients, 24 cases of severe complications were radiologically examined and 3 cases were clinically diagnosed. Five cases of tumor infiltration (1 of the infundibulum hypothalamus, 1 in the sphenoid bone, 1 of the leptomeninges, 1 of the trigeminal nerve, and 1 of the filum terminale) were observed. Three cases of HHV-6 encephalitis were seen with bilateral hippocampal high intensity lesions on diffusion-weighted imaging (DWI). Two subarachnoid hemorrhages, 1 parenchymal hemorrhage and 3 acute infarctions (1 cerebral, 1 in the spinal cord, 1 in the pons) were visualized on DWI and fluid-attenuated inversion-recovery (FLAIR). Two Posterior Reversible Encephalopathy Syndrome (PRES) showed partial contrast-enhancement with high intensity on DWI. A case of acute encephalopathy was caused by virus associated hemophagocytic syndrome (VAHS). A biopsy of the subcortical open-ring enhanced mass histo-pathologically revealed prominent demyelination without tumor infiltration. One patient developed chronic inflammatory demyelinating polyneuropathy (CIDP).Conclusion: Acknowledging these diverse imaging manifestations is beneficial to radiologists.

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C-782 Typical, atypical and misleading MR imaging manifestations of common and not so common cerebrospinal infections R.H.N. Hanasoge, R.V.S.V. Vadapalli, R. Ananthasivan, M. Srinivas, S.K.V. Bommana; Bangalore/IN (raveesh.hn@gmail.com)

Learning Objectives: 1. To illustrate the typical MRI features of common and un-common infections of CNS. 2. To know the atypical and misleading manifestations and to understand the clues to recognize them. 3. To learn about the value of DWI, ADC, DTI with fractional anisotropy and MRS in differential diagnosis.Background: Infections of CNS continue to affect large sections of population. Weird imaging findings in an indeterminate clinical situation continue to fox ev-ery radiologist. We present MRI findings of 20 selected cases of cerebrospinal infections with specific intention of highlighting typical, atypical and misleading presentations.Imaging Findings: All cases were imaged in 1.5 T GE HDx Twin MRI scanner with T1, T2, FLAIR, DWI, MR spectroscopy and DTI sequences. The cases include cerebral infections of actinomycosis (n=1), mucormycosis (n=3), spargnosis (n=1), atypical mycobacteria (n=2), cysticercosis (n=2) cerebral hydatid (n=1), Dengue (n=1), herpes simplex (n=2), JE (n=1), spinal infections ecoli (n=1), staphylococcus (n=2), hydatid (n=1), brucella (n=1). Documentation of the imaging during the evolu-tion of the disease process is done in many cases. Abnormal DWI characteristics as an aid in differential diagnosis are highlighted. FA values and DTI findings and spectroscopic data are analyzed. Where possible operative specimens, gross and microsopic pictures are correlated. The strength and limitations of MRI in diagnosis are discussed.Conclusion: Cerebrospinal infections can produce vague and confusing imag-ing manifestations in addition to their commonly described findings. A thorough knowledge of the myriad of MRI findings helps the radiologist in making a confident diagnosis and guiding the management. Understanding the principles of advanced MRI techniques in the context of infections is very important.

C-783 Cavernous sinus pathology: CT and MRI findings J. Rimoldi, A. Buzzi, A. Gaser, F. Arredondo, Y. Pardo, E. Salum; Ciudad de Buenos Aires/AR (alfredo.buzzi@diagnosticomedico.com)

Learning Objectives: 1. To recognize the complex anatomy of the cavernous sinus. 2. To illustrate the CT and MRI finding of cavernous sinus lesions.Background: The cavernous sinus are multi channeled, extradural venous structures lateral to the sella turca. A wide spectrum of neoplastic, inflammatory, infectious and vascular disease processes affects them. CT, CT angiography, MRI and MR angiography play an important role in the diagnosis of these lesions. We describe and illustrate the most common radiological patterns of lesions that affect and invade the cavernous sinus.Imaging Findings: CT and MRI can identify primary tumors and can assess the spread of the non-neoplastic process affecting cavernous sinus. The entities in-clude neoplasms (e.g., meningiomas, trigeminal schwannomas, invasive pituitary adenomas, linfomas, metastasis), inflammatory and infectious diseases (e.g., pituitary abscess, thrombophlebitis, Tolosa-Hunt syndrome), and vascular lesions (e.g., aneurysm, carotid-cavernous fistula).Conclusion: Imaging studies are essential for the evaluation of the tumors and non-neoplasic processes affecting the cavernous sinus. MR has become the dominant modality as it allows a multiplanar approach and direct visualization of the lesions and adjacent structures involvement.

C-784 Precise image-guided infrequent therapeutic and diagnostic neurointerventional procedures A. Kraus, C.K. Jadun, P.S. Dias; Stoke-on-Trent/UK (boletus@gmx.net)

Learning Objectives: To show a variety of infrequent/unusual neuro-radiological diagnostic and therapeutic interventions, where precision is absolutely essential and can be achieved using CT, fluoroscopy and ultrasound.Background: There are a variety of minor interventions of the central nervous system and spine absolutely essential for clinical management, which carry potential risks and can be performed in a neurointerventional suite, thus obviating exposure to long neurosurgical interventions.Procedure Details: The procedures performed included US-guided brain abscess drainange, para carotid neck tumour biopsy, skull base tumour biopsy along the C1 vertebra avoiding the internal jugular vein and the vertebral arteries, contrast medium injection into a brain arachnoid cyst to check for patency of neurosurgically performed endoscopic fenestration, vertebral and paraspinal biopsies, cervical

nerve root injections at all levels, pars defect blocks, CT-guided facet joint synovial cyst puncture, CT-guided piriformis botox injection and fluoroscopy-guided lumbo-peritoneal shunt insertion in failed neurosurgical cases. These interventions were done either under CT/CT-fluoroscopic, fluoroscopy or ultrasound control.Conclusion: Precise image guidance is mandatory for successful diagnostic and therapeutic radiological procedures. Quite often, it avoids major surgery and is valuable in therapy and diagnosis or localization of a clinical problem. In our hospital, the clinicians as well as patients appreciate the minimal invasive nature, quick turnaround time and precision of these interventions for the management of day-to-day cases.

C-785 Anatomy and pathology of the brainstem: A gaze into the stem of life M.A. Fernández-Gil, R. Palacios Bote, R. Querol Pascual, M. Ortega Martínez, G. Guerrero Martínez, F. Ugarriza Echevarrieta; Badajoz/ES (mafdezgil@telefonica.net)

Learning Objectives: 1. To illustrate the internal structure of the brainstem and provide an overview of the common and uncommon pathologic processes affecting the brainstem. 2. To evaluate the efficacy and utility of MR imaging in the diagnosis and management of these conditions. 3. To give diagnostic clues that help make an accurate diagnosis and a rational approach to the differential diagnosis.Background: Brainstem lesions are a diverse group of entities that often lead the patient to a disabling situation. Many of these disorders may exhibit similar symptoms, but in a great proportion of cases they reveal characteristic MR imaging appearances. On this basis, this work will help to better understand and recognize pathologic processes that affect the brainstem such as ischemia, intrinsic and extrinsic tumors, demyelinating disease, neurodegenerative diseases, traumatic, vascular, infection, and exceptional disorders like Erdheim-Chester disease, giving the key findings of each group of lesions.Procedure Details: MRI is the technique of choice to explore lesions located in the brainstem. The key findings of each group of lesions are shown and compared with the surgical findings or underlying pathologic features when available. Pitfalls, diagnostic difficulties and differential diagnosis are emphasized.Conclusion: The intricate structure of the brainstem makes its knowledge a real challenge. This presentation dives into the frightful anatomy of the brainstem, high-lights the landmarks that are important in interpreting MRI and attempts to provide a guide to help the radiologist in the diagnosis of brainstem pathology.

C-786 MR imaging of rare congenital and acquired pathology of sellar and parasellar regions A.C. Athanassopoulou, I.V. Kalogeropoulos, A.N. Chalazonitis, G. Neofitou, M. Kelogrigoris, A. Kokkinaki, P. Piperopoulos, A.D. Gouliamos; Athens/GR (red-rad@ath.forthnet.gr)

Learning Objectives: 1. To describe the MR imaging appearance of rare con-genital and acquired diseases of sellar and parasellar regions specific to adults and to children. 2. To propose a diagnosis based on suggestive findings for almost every lesion.Background: While pituitary adenomas, meningiomas and craniopharyngiomas represent the 75% of sellar and parasellar lesions, there is also a number of rare congenital and acquired lesions which may arise within the sellar and parasellar regions. Knowledge of the imaging appearance of these lesions is important for accurate diagnosis and treatment.Imaging Findings: In our exhibit, we will present the rare congenital and acquired diseases of sellar and parasellar regions which are reviewed and illustrated with MRI. The congenital conditions include: hypoplastic pituitary; absence of the pituitary stalk; ectopia of the posterior lobe; empty sella; hamartoma and ectopic hamartoma; herniation of the pituitary gland; Ratke’s cleft cyst; and arachnoid cyst. The acquired conditions include inflammatory (bacterial meningitis and TB meningitis); neoplastic; hematologic; (hemocromatosis) and vascular diseases (aneyrysms etc.).Conclusion: MR imaging may provide to the radiologists and the medical doctors a valuable help for an accurate diagnosis of the lesions located in the sellar and parasellar regions, something very important considering the fact that the variety of diseases which may occur locally are making the diagnosis very difficult.

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C-787 Neurological imaging findings of neurocutaneous syndromes (phakomatosis) in MRI: A pictorical review C. Andreu, B. Lopez-Botet, M. Manzano, J. Cuesta, R. Manzanares, L. Fernandez Fresno; Madrid/ES (carlotaandreuarasa@yahoo.com)

Learning Objectives: 1. To review concepts about phakomatosis as syndromic diseases including neurological and extra-neurological features. 2. To show radiologi-cal findings of neurologic affection of these syndromes. 3. To explain the findings from an embryological point of view.Background: Magnetic resonance, through its classical sequences and advanced methods, such as diffusion and spectroscopy, allows a clear and correct diagno-sis of this infrequent group of diseases. Phakomatosis are a group of hereditary diseases of neuroectoderm, distinguished by cutaneous manifestation, due to which are also named neurocutaneous diseases. These are neurofibromatosis, tuberous sclerosis, Von Hippel-Lindau’s disease and the Sturge-Weber’s syn-drome. Essential lesions are neurogenous tumor, tuber, hemangioblastoma and angiomatosis, respectively.Imaging Findings: We have undergone retrospectively through the cases of the last five years of our data base, reviewing radiological findings in MRI of neurologi-cal affection of neurocutaneous syndromes. Histologic examination of cutaneus lesions were performed in all cases with dermatological lesions.Conclusion: MRI is an excellent, non-invasive modality for detection, diagnosis and evolution of neurological processes of neurocutaneous syndromes. This poster presents the vast spectrum of neuro-radiological features of phakomatosis and encloses them in a frame of syndromic diseases.

C-788 Embryology, anatomy and pathology of the pituitary gland and perisellar region: MR imaging features S. Van Damme, W. Bauters, L. Jans, N. Herregods, K. Verstraete, E. Achten, K. Deblaere; Gent/BE (stijnvandamme@gmail.com)

Learning Objectives: (1) To describe and illustrate the embryology and normal anatomy of the pituitary gland and perisellar region. (2) To illustrate the MR imag-ing spectrum of pathologies of the pituitary gland and perisellar region at 1.5 T and 3 T.Background: The complexity of the anatomy of the pituitary gland and perisellar region is inherently linked to that of its embryological development. Appreciation of the embryology provides a better insight in the anatomy and thus is the key to recognise and diagnose the various developmental anomalies and pathologies in this region.Imaging Findings: An overview of the embryology and anatomy of the (peri)sellar region is presented. A wide variety of pathology, consisting of congenital anomalies as well as infectious and tumoral processes affecting this region, can be found. MR imaging can clearly demonstrate the relationship of pituitary lesions to perisellar structures such as the optic chiasm and cavernous sinus, providing information in three orthogonal planes. In addition, MR imaging has the capability of distinguishing solid, cystic and hemorrhagic components of lesions. 3 T imaging, providing more detailed images than 1.5 T imaging, can be used to better delineate small lesions and their relationship with surrounding structures.Conclusion: Knowledge of the embryology and normal anatomy is the key to the radiologic evaluation of the pituitary gland and perisellar region. Current MR imaging techniques allow to clearly depict the various developmental anomalies and pathologies in this region and to make an early diagnosis.

C-789 Dural arteriovenous fistulae of the cavernous sinuses on contrast-enhanced 3D dynamic MR angiography H. Akiba, N. Yama, M. Tamakawa, H. Hyodoh, K. Hyodoh, M. Hareyama, T. Satoh, Y. Kawai; Sapporo/JP (akibah@sapmed.ac.jp)

Purpose: To assess the capability of contrast-enhanced 3D dynamic MR angiogra-phy (3DdMRA) as a flow-independent approach, together with those of conventional MR imaging techniques, for the diagnosis of dural AVFs of the cavernous sinuses comparing with the result of selective angiography.Methods and Materials: This study included 18 angiographically confirmed pa-tients with dural AVFs of the cavernous sinuses and 15 control subjects. Sixteen partially overlapping sequential MR images were acquired on 3DdMRA between the petrosal and orbital roof after bolus injection of contrast material every 2.3-5 seconds. Transverse 3D fast spoiled gradient recalled echo sequence was em-ployed on 3DdMRA. Two experienced radiologists blinded to the clinical data and the result of angiography independently observed for the diagnosis on 3DdMRA,

fast-spin-echo-T2 weighted image (FSE-T2WI) and time of flight MR angiography (TOF-MRA).Results: The average Az values for the diagnosis of dural AVFs on 3DdMRA, FSE-T2WI, and TOF-MRA were 0.994, 0.885, and 0.952, respectively, and there was a statistically significant difference between the former two (P 0.05). The interobserver kappa scores were 0.93, 0.71, and 0.73, respectively. The average Az values and interobserver kappa scores for the diagnosis of the anterior, posterior, and retrograde cortical venous drainages on 3DdMRA were 0.738, 0.958, and 0.836; 0.57, 0.55, and 0.56, respectively.Conclusion: 3DdMRA enables the direct demonstration of dural AVFs of the cav-ernous sinuses and not only allows the confirmation or exclusion of dural AVFs for screening but also may provide information of the main venous drainages.

C-790 Double reading (DR) of neuroradiological MRI: Results of a 12 months period M. Serrallonga, E. Grivé, S. Domènech, C. Schorlemmer, H. Billing; Barcelona/ES

Purpose: Double reading (DR) aims to improve diagnostic accuracy and to reduce the incidence of errors. We present our experience in DR over a 12 month period.Methods and Materials: TMC provides a teleradiology service throughout Europe. We have retrospectively reviewed DR done in 2006 by 8 experienced neuroradiolo-gists from several European countries. The disagreements are graded as: Grade 0: full agreement, Grade 1: changes with no clinical consequences, Grade 2: changes made unlikely to have significant clinical consequences, Grade 3: changes with potential clinical significance, Grade 4: high potential for clinical consequences. For Grade 0, the report issued by the first reader was approved. For Grade 1, changes introduced by the second reader were considered as definitive. For Grades 2 to 4, changes were communicated to the first reader for discussion and to give the opportunity to agree or disagree. When no consensus was achieved, the section leaders decided the final diagnosis.Results: Out of a total of 18,825 neuroradiological reports most disagreements were of no clinical consequence (56.11% Grade 0; 30.43% Grade 1 and 9.26% Grade 2). Clinically important disagreements were only about 4% (3.91% Grade 3 and 0.30% Grade 4). We categorize errors as hypo-concentration errors (“slip-mistakes”), radiologist expertise-dependent errors (misinterpretation) and oversight omissions.Conclusion: Systematic and controlled DR lowers diagnostic errors/mistakes, improves reporting skills and is an important tool for sharing experience. It also provides for a high level of clarity and comprehension in the reports. Ultimately, most discrepancies were simply due to different reporting styles.

C-791 Four dimensional imaging of the normal and pathological pituitary gland by using TRICKS on 3 T MRI A. Wada, T. Hayashi, T. Katsube, N. Okada, N. Yamamoto, Y. Tsuchie, T. Yoshizako, N. Uchida, H. Kitagaki; Izumo/JP (awada-ind@umin.ac.jp)

Purpose: TRICKS (Time Resolved Imaging of Contrast KineticS) is a recent 3D gradient echo technique with characteristic 3D k-space segmentation and data recombination. Additional parallel imaging technique (ASSET) contributes to higher spatial resolution (sub-square millimeter) 3D imaging without sacrificing temporal resolution.Methods and Materials: Three dimensional dynamic MR imaging of pituitary gland was performed to five normal and three pathological subjects. All MR examination was performed on 3 T MR unit (Signa HDx 3.0 T: GE Healthcare) with 8 channel head coil. Parameters of TRICKS are the following: TR/TE: 4.48/1.36 msec, FA15, FOV:18 cm, matrix: 256x256, slice thickness 2 mm, colonal plane, acquisiton time: 2 sec. 10 ml Gd-DTPA and 20 ml saline were injected with flow rated of 2 ml/sec.Results: In all cases, progress of contrast enhancement from pituitary stalk to anterior gland was recognized distinctly. 4D viewing (time resolved 3D viewing) based on multiplanar projection technique revealed the extension of intra-pituitary gland contrast enhance effect from center to periphery sequentially and 4D viewing contributed to detection of the pituitary microadenomas.Conclusion: 4D MR imaging of pituitary gland is useful for the evaluation of normal and pathological pituitary gland.

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C-792 Dynamic relationships model of the craniospinal fluids in healthy volunteers using phase contrast magnetic resonance imaging N. Flórez, D. Moratal, L. Martí-Bonmatí, J. Forner, E. Arana; Valencia/ES (Luis.Marti@uv.es)

Purpose: To characterize the pulsatibility of the cerebrospinal fluid (CSF) flow and blood flow within the craniospinal axis following a reproducible quantification model that allows to establish spatiotemporal relationships between the CSF flow in the aqueduct of sylvius (S), spinal CSF (C2C3), blood flow in the intern carotid arteries (ICA), vertebral arteries (VA) and jugular veins (JV).Methods and Materials: Ten healthy volunteers with a mean age of 27 5 years were scanned with a 3.0 T scanner. Three PC sequences were obtained: oblique axial perpendicular to the aqueduct of sylvius with Venc= 15 cm/s, axial at the level of C2-C3 with Venc= 7 cm/s for subarachnoid CSF flow and Venc= 80 cm/s for vascular flow. The main image parameters included FOV= 170 mm, 5 mm slice thickness, matrix size= 512 x 512, minimum TR, minimum TE and 25 frames per cardiac cycle with use of peripheral pulse retrospective gating. The regions of interest were delineated and analyzed on a software developed using MATLAB R7.Results: The main parameters obtained were: mean flow in ICA= 672 ml/min, VA=185 ml/min, JV=485 ml/min, S=8 ml/min, C2C3=68 ml/min, mean flow amplitude in ICA= 1079 ml/min, VA=436 ml/min, JV=946 ml/min, S=27 ml/min, C2C3=293 ml/min, stroke volume in S=64μl/cycle, C2C3= 571 μl/cycle, stroke volume ratio=12%, production rate in S=0.53 ml/min, and delay time between systolic peaks of flow waveforms in.s. and ICA was 123 ms.Conclusion: This study provides a quantitative model that characterizes the global pulsatibility of the craniospinal fluids. Any imbalance can be considered as neurological disturb.

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C-793 Extra spinal sciatica revisited: A pictorial essay of CT and MRI features R.M.S.V. Vadapalli1, R. Mulukutla2, R. Ananthasivan3, D. Singh3, E. Bari3; 1Colombo/LK, 2Hyderabad/IN, 3Bangalore/IN (rammohanvsv@yahoo.com)

Learning Objectives: 1. To understand the anatomy and course of sciatic nerve. 2. To understand the concept of extraspinal sciatica. 3. To elucidate the importance of Pyriformis syndrome and its clinical significance. 4. To illustrate the causes of pelvic and extra pelvic sciatic nerve compression.Background: Uncommonly, sciatic nerve can be compressed during its course to and beyond greater sciatic notch. This exhibit focuses on MR imaging of extraspinal sciatica highlighting the gamut of causes.Procedure Details: This exhibit highlights the importance of comprehensive back-ache protocol with imaging of sciatic nerve in routine clinical practice to evaluate its extraspinal compression in pelvis and demonstrate the extra pelvic causes (beyond sciatic notch). All patients were imaged on 1.5 T /3 T MRI systems at two imaging centers using a multichannel spine coil, pelvic phased array coil. 2D steady state FIESTA axials, c oronals and sagittals, STIR coronal and pre and post contrast T1 weighted fat suppressed sequences. For MR neurography an additional DWIBS (diffusion weighted imaging with background suppression) was used. Pathologies discussed include neoplastic compression of the nerve by intra and extraneural tumors, injuries, iatrogenic causes, and aneurysms to name a few.Conclusion: MR neurography sequence should be included in a comprehensive backache protocol in patient with sciatica to rule out extra pelvic sciatic nerve compression and lesion characterization.

C-794 Spine demyelinizating chronic disorders: A MR DTI-fiber tracking study A. Paniagua Bravo, J. Romero Martínez, G. Medrano Seoane, J. Ciampi Dopazo, S. Ossaba Vélez; Madrid/ES (alvpaniagua@yahoo.es)

Learning Objectives: Spine MRI-Diffusion Tensor Imaging (DTI) was performed in 12 patients with chronic demyelinating disorders and 3 healthy individuals. Our purpose was to show its normal anatomy as well as the pathological changes in some demyelinating diseases that involve it.Background: The Diffusion Weighted Imaging (DWI) is a useful technique to obtain maps from the white matter tracts. Our study is focused on the assessment of the spine after performing DWI maps to visualize the different white matter tracks of the spinal cord. When compared to the results in normal subjects, we study the anatomical changes caused in chronic demyelinating disorders, basically multiple sclerosis, and describe the main pathological features.Procedure Details: All the studies were performed on a 1.5 T MR unit by using a single-shot echo-planar imaging sequence (flip angle: 90º, TR:7803, TE:88, NSA:4) with b=1000 mm2/sec. An acquisition time of 8:35 was needed. We also acquired an anatomic imaging 3D/DTI. Postprocessing was made in a workstation using the Philips PRIDE software. We obtained 2D and 3D colour maps from the spine.Conclusion: DTI seems to be a useful technique for studying white matter tracts of the spinal cord. Demyelinating disorders frequently cause anysotrophy of the white matter fibers that can be visualized with the DTI study. 3D color maps of the white matter fibers show neuronal damage and compare it with the local surround-ing spinal cord tracts.

C-795 Imaging spectrum of Hirayama flexion myelopathy S.S. Krishnan, N. Chidambaranathan; Chennai/IN (susi.krishnan@gmail.com)

Learning Objectives: To illustrate the spectrum of Magnetic Resonance (MRI) findings in Hirayama flexion myelopathy. To outline the importance of flexion MRI over the neutral position and dynamic MRI of the cervical spine based on findings in a series of five patients.Background: Juvenile muscular atrophy of the distal upper limb (Hirayama disease) is a rare disease predominantly affecting the anterior horn cells of the cervical spinal cord in young men. Clinically, this mimics motor neuron disease. Flexion MRI helps to differentiate Hirayama disease by depicting forward displacement of the posterior dural sac. The neutral position and dynamic MR findings in five patients aged between 16 and 32 years who presented with progressive unilateral upper limb weakness and wasting are illustrated.Imaging Findings: Axial and sagittal T1 and T2 weighted sequences of the cervical spine in neutral position, sagittal T2 WI in flexion and extension were performed on

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a 1.5 T MR scanner.The neutral position findings included localized lower cervical cord atrophy (commonly at C5-C6 level), asymmetric cord flattening, abnormal cervical curvature, loss of attachment from posterior dural sac and subjacent lamina, and noncompressed intramedullary high signal intensity. The character-istic finding on flexion MRI was forward migration of the posterior surface of the dura with spinal cord compression, in addition to a congested posterior internal vertebral venous plexus.Conclusion: In an adolescent patient with distal upper limb weakness, asymmetric cord atrophy, especially at the lower cervical cord in routine cervical MRI warrants a flexion MRI study to prove this diagnosis.

C-796 Diffusion tensor imaging and MR spectroscopic findings of cervical spinal cord M. Hori, S. Aoki, O. Abe, H. Kabasawa, K. Ohtomo, A. Yamaguchi, M. Shimada, N. Shiraga; Tokyo/JP (masahori@med.toho-u.ac.jp)

Learning Objectives: To learn normal anatomy and pathological condition of cervi-cal spinal cord on diffusion tensor imaging and MR spectroscopic findings.Background: In the evaluation of cervical spinal cord pathology, MR imaging plays an important role because the spinal cord lesions are often difficult to target by biopsy without complications. Recently, improvement hardware and software, diffusion tensor imaging (DTI) and MR spectroscopy (MRS) were ready to estimate cervical spinal cord. Normal anatomy and pathological condition of cervical spinal cord on diffusion tensor imaging and MR spectroscopic findings are described and illustrated.Procedure Details: The quantitative measurements (apparent diffusion coefficient, ADC and fractional anisotropy, FA) and 3D white matter fiber tracking were useful to estimate cervical spinal cord diseases in clinical use. For example, the ADC value of spinal cord in patients with cervical spondylotic myelopathy increased (P .001, Mann-Whitney U-test) and FA decreased on average, compared with those in normal volunteers. Low signal line on FA map may indicate the tear of the white matter fiber in patient with spinal AVM and white matter fiber tacking based on DTI is poorly demonstrated at the affected level on3D tractography. MR spectroscopic findings of normal and pathological sites in the cervical spinal cords were similar to those in the brain; however, a little difference was observed in quantitative analysis.Conclusion: DTI and MRS of cervical spine provide additional information in evaluation of cervical cord lesions in addition to conventional MR imaging. They were promising in clinical use.

C-797 Spondylodiscitis: Spectrum of imaging findings A.S.R. Preto, M. Pimenta, D.M. Rocha, C. Reis, J. Gonçalves; Porto/PT (sofiapreto@hotmail.com)

Learning Objectives: Review the state of the art in diagnosing this infection that involves one or more of the extradural components of the spine. Summarize the current use of several imaging techniques and provide relevant findings. The pathophysiology and clinical details will also be reviewed.Background: Although infective spondylitis affects a small proportion (2-7%) of all patients with osteomyelitis, it is important because of its potential morbidity and mortality. Its complications include paraspinal and epidural abscess formation. The 3 main routes of spinal infection are hematogenous spread, direct inoculation, and contiguous spread.Imaging Findings: Although plain images, CT, or nuclear medicine studies can help establish the diagnosis, MRI is considered the modality of choice for evaluat-ing the presence and severity of spinal infection. MRI is especially effective for evaluating the neural structures of the spine (i.e., spinal cord, nerve roots) and extradural soft tissue. Along with appropriate history taking, physical examination, and positive blood cultures, findings on MRI or radionuclide studies can confirm the diagnosis. CT is most useful for characterizing vertebral osteomyelitis in patients with subacute or chronic illness. CT provides radiologic guidance for interventional procedures (i.e., biopsy, drainage). Conventional radiographs are insensitive to the acute changes of infective spondylitis but can be used on a limited basis to follow-up on chronically ill patients.Conclusion: MRI is the modality of choice. In particular, MRI is useful in detecting abnormalities in the acute stage of spinal infection. This is vital in therapeutical management.

C-798 Radiological study of biodegradable spinal implant in cervical arthrodesis M. Gimeno, R. Lasierra, J. Calatayud, C. Del Rio, B. Carro, J. Pina; Zaragoza/ES (mjgimeno@comz.org)

Purpose: To report our experience and radiological findings and follow-up in cer-vical artrhodesis using biodegradable cervical fusion plate for graft containment composed of L-polylactic and DL-polylactic acid.Methods and Materials: From June 2006 to February 2007, 8 biodegradable anterior cervical fusion plates for graft containment in fusion of cervical vertebrae were implanted in 8 patients. Inion S-1TM is a biodegradable anterior cervical fusion plate for graft containment in fusion of cervical vertebrae. 3 men and 5 women. Mean age 44.2 years old (23-56). Procedures involved C4-C5 in 1 patient (man), C5-C6 in 5 patients (2 men and 3 women), C6-C7 in 1 patient (woman) and C5-C6-C7 in 1 patient (woman). All patients presented degenerative cervical disease with neurological symptoms.Results: All patients experienced significant clinical improvement. Radiological follow-up was performed with X-ray, CT and MRI (the device does not interfere with magnetic resonance imaging). In the 9 patients was demonstrated radiological stability of cervical vertebrae and absence of motion on dynamic X-rays. There were no clinical signs or symptoms of reaction to the bioabsorbable material. Patients do not require a removal operation.Conclusion: Cervical artrhodesis after discectomy is a useful method for treatment of cervicobrachialgia. Artrhodesis with biodegradable anterior cervical fusion plate for graft containment in fusion of cervical vertebrae achieves similar clinical results than other artrhodesis methods with a best radiological performance. This method presents some other advantages (absence of time migration, absence of reaction to the material, absence of removal operation and psychological factors).

C-799 Spinal DTI for dummies E. Sánchez, E. Marco de Lucas, E. Ruiz, A. Gutiérrez, F. Quintana, I. Bañales, A. Fernández Flórez, J. Izquierdo, J. Crespo del Pozo; Santander/ES (radmle@humv.es)

Purpose: To resume the key facts of this new diagnostic technique applied to the spinal pathology with an easy point of view, analyzing the different main possible clinical applications. What do I need to perform DTI, which image quality can I expect for and what can I benefit from it?Methods and Materials: We present an easy overview including basic physics, main technical problems and clinical applications. A review of several clinical cases is included where DTI may have a key role in the diagnostic management of patients. These images presented include both diffusivity, ADC, fractional anisotropy and colour encoded maps generated in cases of vertebral and spinal cord pathology.Results: Diffusion-weighted imaging and fractional anisotropy must be included in the diagnostic work-up of magnetic resonance imaging techniques performed for vertebral and spinal cord lesions. Diffusivity and anisotropy imaging provides additional diagnostic information for the evaluation of inflammatory, vascular and neoplastic lesions. In addition, tractography may provide visualization of cervical white matter tracts useful for anatomical and diagnostic information. In addition, some technical problems and limitations still observed for daily clinical practice are described.Conclusion: Diffusion tensor imaging is a new technique to be included in spinal MR studies because it provides very useful functional information.

C-800 Usefulness of CSF flow-cine MRI for spinal pathology N. Valle, E. Sánchez, E. Marco de Lucas, R. Pellón, L. Martín, V. Álvarez de Eulate, E. Ruiz, A. Gutiérrez, A. González Mandly; Santander/ES (radmle@humv.es)

Purpose: To show the main possible clinical applications of cine-MRI dynamics of CSF for spinal pathology. To analyze the main technical characteristics and possibilities of this sequence.Methods and Materials: We present an easy overview including basic physics, main technical problems and clinical applications of this sequence. We reviewed the cine-MRI imaging of vertebral canal performed with a spine-multicanal coil in a 3 T unit where it provides useful complimentary pathophysiologic information. Imaging from both physiologic and pathologic conditions was reviewed.Results: CSF-flow spinal cine-MRI can be useful by providing evaluation of CSF spaces. This technique shows the normal CSF flow in the vertebral canal with wave motion along the length of the spinal cord. In addition, it shows the stop or restriction of the flow caused by several pathologies, including spinal malformations

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from Chari to dysraphisms; neoplasms from spinal cord and vertebral bodies; spinal cord tethering associated to inflammatory diseases; and the changes associated with vertebral canal stenosis from degenerative changes. In addition, it provides valuable information after surgical decompression. In addition, we analyze its usefulness as complimentary test for detection of important flow artifacts of spin echo images in 3 T.Conclusion: Spinal CSF flow cine-MR imaging helps to evaluate different diseases affecting the spinal canal and to identify the specific pathophysiology involved.

C-801 Tuberculous spondylitis with nonsurgical treatment: MR imaging characteristics in follow-up period and correlation with drug response H. Gweon, D. Kim, S. Suh, T.-S. Chung, D. Kim, K. Kim, Y. Cho; Seoul/KR (choikim@nate.com)

Purpose: To review MR features of tuberculous spondylitis with nonsurgical treat-ment and compare them with drug-response to antituberculous chemotherapy.Methods and Materials: From 2000 to 2006, patients with proven tuberculous spondylitist, who had nonsurgical treatment, were retrospectively included. MRI was performed more than twice, including at baseline, every 3 or 6 months and at the end of treatment. All MRI examinations were done with a 1.5-T device (Vision, Siemens, Germany). All the images were analyzed and correlated with the clinical outcome and drug response to antituberculous chemotherapy.Results: 10 patients (male:female=6:4, mean age=45 years) were enrolled. Back-ache (90%) and fever (10%) were present in patients and neurological signs were not present. The distribution of spinal lesion was thoracic in 3 patients, lumbar in 6 and noncontiguous lesions in 1. All patients showed bone marrow edema in the involved vertebra. Two vertebrae were involved in 6 patients, three vertebrae in 2 and more than four vertebrae in 2. Spinal cord compression was noted in 3 patients. 9 patients had abscess, which were epidural, paravertebral and psoas. Follow-up MR images showed loss of subligamentaous spread (6/6), decreased volume of abscess (6/6), and fibrosis (6/6) in drug-responsive group (n=6). In drug-resistant group (n=4), further extension of bone marrow edema into the adjacent vertebra (1/4), further extension of abscess (4/4), decreased height of vertebral body (3/4) and extensive subligamentous spread (3/4) were presented.Conclusion: In the nonsurgical management of tuberculous spondylitis, MRI may have an important role of predicting the response to antituberculous che-motherapy.

C-802 High-resolution, three-dimensional MRA using intravascular contrast agent in detection of spinal AV malformation L. Klzo, J. Zizka, A. Krajina, P. Ryska, V. Málek; Hradec Kralove/CZ (ludek.klzo@seznam.cz)

Purpose: Contrast magnetic resonance angiography (MRA) can be used to visu-alise feeders and nidus of the arterio-venous malformations (AVM). Authors are presenting three cases with first use of the intravascular contrast agent in high-resolution, three-dimensional MRA.Methods and Materials: Three patients with suspected dural AVM were examined in our MRI department. Standard imaging protocol and high-resolution, three-di-mensional MRA was used. After administration of 0.1 mmol/kg of the intravascular contrast agent, albumin-binding gadolinium chelate, gadofosveset trisodium, for the first pass imaging we used time resolved contrast enhanced MRA with lower resolution. Imaging in steady-state phase of the contrast agent with sub-millimeter in-plane resolution was also performed.Results: In two of the patients we were able to find feeder of the dural AVM and also extension of dilated vessel surrounding spinal cord. Both patients were suc-cessfully treated and feeding vessel was confirmed by DSA. In the third patient AVM was not found neither using MRA nor DSA.Conclusion: High-resolution, three-dimensional MRA using intravascular contrast agent can be used as a precise diagnostic tool for spinal AVM detection.

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C-803 Assessment of hepatoblastoma: Impact of the radiology in its therapeutic approach E. Valbuena, M. Parrón, J. Fernández-Cuadrado, I. Pastor, P. García Miguel, C. Prieto; Madrid/ES (emiliovalbuena@hotmail.com)

Learning Objectives: To illustrate the spectrum of hepatoblastoma imaging fea-tures. To expose the diagnostic algorithm used in management of these children in our institution. To detail the radiological staging and discussing its relevance on treatment strategies.Background: Hepatoblastoma is the most common malignant liver tumor of childhood. There are different approaches to treat hepatoblastoma, including SIO-PEL-protocol of International Childhood Liver Tumor Strategy Group. Treatment is stratified according to imaging findings on high-risk and standard-risk hepatoblas-toma. Surgical choice (hepatectomy, liver transplantation) is based on PRETEXT (PREtreatment-EXTent) staging system, where the radiologist has the greatest role, providing information about local and extrahepatic extension.Procedure Details: From 1990 to 2007, 52 children with hepatoblastoma were treated in our institution according to SIOPEL-protocol. When hepatoblastoma is suspected in a child with an abdominal mass, ultrasonogram and alpha-fetoprotein are the first tests performed. PRETEXT staging is achieved with abdominal multide-tector-CT or MR to evaluate the tumoral resectability (liver sections affected, portal, hepatic, and cava involvement) and extrahepatic abdominal extension. Thoracic-CT is essential to rule out lung metastases. Additional techniques (bone scintigraphy, brain MR) are only recommended when symptoms are present. Imaging is also an important tool guiding the needle-biopsy. After preoperative chemotherapy, a new abdominal CT/MR is necessary to re-evaluate the mass and choose the best surgical option.Conclusion: This exhibit highlights the crucial contribution of the radiologist on diagnosis, staging, and proper therapy planning of hepatoblastoma. The viewer will obtain an understanding algorithm for an adequate hepatoblastoma management, based on imaging findings and PRETEXT staging system.

C-804 Complications following pediatric liver transplantation through 64-slice computed tomography: A wise approach G. Gallardo-Madueño, M. Parrón, I. Pastor, C. Prieto, R. Rodríguez-Lemos, M. López-Santamaría; Madrid/ES (ggallar@gmail.com)

Learning Objectives: To assess the utility of 64-multidetector-computed tomog-raphy (MDCT) for diagnosing complications in pediatric liver transplantation (PLT). To establish reasonable indications of this technique. To present our protocol, emphasizing dose adjustment and advantages of different reformations.Background: PLT presents a high rate of vascular and biliary complications due to partial grafts used, sometimes in infants less than 1years-old, involving an imaging techniques limitation. Ultrasonography (US) is the initial modality of choice for detection and follow-up of complications. MR usually has been stood for inconclusive US results, particularly for vascular complications. However, the new 64-MDCT is a valuable tool, especially in urgent vascular complications, thanks to its higher availability, speed, spatial-resolution, and safety with common postsurgical materials or devices.Procedure Details: Fifty-five PLT were performed during the last 20 months. Fifteen patients underwent a 64-MDCT scan, mainly after urgent vascular complications suspicion in US. Our protocol includes a hepatic arterial and portal phases with automatic bolus triggering (adding a systemic venous phase when vena cava pathology is presumed). Automatic radiation exposure adjustment is used, obtain-ing high quality images with lowest radiation dose. The most useful reformations are multiplanar-reconstrutions (MPR), maximum-intensity-proyections (MIP), and volume-rendering (VR). Vascular complications recorded were hepatic artery, portal vein, and vena cava stenosis and thrombosis. Fluid collections and biliary stenosis were the non-vascular complications found.Conclusion: 64-MDCT is an accurate and nearly instantaneous method of ex-amining PLT complications, fundamentally the urgent vascular ones. The robust imaging findings contribute to establish firm diagnosis and, therefore, crucial clinical decisions (i.e. retransplantation) with reasonable radiation doses.

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C-805 Congenital intrahepatic portosystemic shunts J.M. O’Brien, D. Rea, A. Broderick, E. Phelan; Dublin/IE (julieM.obrien@amnch.ie)

Learning Objectives: The purpose of this presentation is to demonstrate the imaging findings of congenital intrahepatic portosystemic shunts, and therefore allow for their recognition when characteristic features are present. We will also discuss the pathophysiology and clinical relevance of these vascular shunts with review of the current treatment options.Background: Congenital anomalies of the portovenous system are very rare. To the best of our knowledge, less than ten cases of congenital intrahepatic portosystemic shunts have been reported in the literature. Due to the rarity of these lesions, treat-ment regimes vary, depending on the nature and severity of the case.Procedure Details: We reviewed our radiological database in a tertiary referral children’s hospital and examined the cases of intrahepatic portosystemic shunts in neonates between October 2005 and December 2006. We present the radiological findings and outcomes of each, with review of the current literature.Conclusion: This pictorial exhibit focuses on the various imaging appearances and clinical characteristics of congenital intrahepatic portosystemic shunts. We hope to familiarise the reader with this condition, thus allowing confident radiologi-cal diagnosis on imaging grounds. We will elegantly demonstrate the usefulness of imaging modalities in the treatment planning of these patients, as well as the therapeutic role of interventional radiology.

C-806 Imaging findings of pancreatic disorders in children R. Sanchez1, I. Solis2, E. Stranzinger1, C. Serrano2; 1Ann Arbor, MI/US, 2Murcia/ES (inessolis@yahoo.es)

Learning Objectives: Our aim is to expose the imaging findings and the role of different imaging techniques in the diagnosis of pancreatic pathology affecting children.Background: The pancreatic gland can present a spectrum of lesions including developmental abnormalities and hereditary disorders affecting the pancreas such as cystic fibrosis and Schawmann-Diamond syndrome, which are mainly diagnosed in children. Blunt abdominal trauma injuries, neoplasms and inflammatory diseases also constitute an important source of pancreatic pathology in children.Imaging Findings: Computed tomography and magnetic resonance with MR cholangiopancreatography sequences are the leading imaging techniques used in the study of the pancreas. We review the developmental anomalies including pancreas divisum, annular pancreas, ectopia, agenesia and hypoplasia of the gland. We also illustrate imaging appearances in trauma, changes in the gland due to acute or chronic inflamatory diseases and neoplasms, which are uncom-monly found in children.Conclusion: Pancreatic disorders are a significant cause of morbidity in children. Knowledge of the imaging features in the different diagnostic techniques available for the study of the pancreatic gland in children is important for all radiologists to avoid potential pitfalls and misdiagnoses.

C-807 Duodenal diseases in children: A pictorial essay G. Pose, C.I. Whittle, G. Soto Giordani, A. Bataszew, G. Palominos; Santiago/CL (gpose@alemana.cl)

Learning Objectives: Present a pictorial essay of the main diseases that affect the duodenum in children.Background: The duodenum is the shortest segment of the small intestine. In children, a large variety of pathologies that differ largely from those seen in adults affect it. Congenital causes are important and may be symptomatic early in the patient’s life. Inflammatory disease including peptic ulcer, duodenitis and Cohn’s disease usually presents in older children. Tumoral pathology is extremely infrequent. Miscellaneous diseases including foreign bodies and polyps have to be included in the differential. Simple abdominal radiographs, upper gastrointestinal barium studies, US and CT are the main imaging modalities used in their evaluation. Publications in this subject are few. We present an imagenological review of this subject describing the main findings for each entity.Imaging Findings: The imaging findings of the following diseases are shown and discussed: 1. Congenital diseases including malrotation, duplication cysts, duodenal web, duodenal stenosis and atresia are frequent and may present early in life. 2. Extrinsic duodenal compressions secondary to Ladd’s band, annular pancreas, mesenteric clamp, choledocal cyst and preduodenal portal vein. 3. Inflammatory lesions such as peptic ulcer, duodenitis and Crohn`s. 4. Miscellaneous lesions: foreign bodies and polyps.

Conclusion: In children, duodenal pathology differs from the one seen in adults. Congenital lesions or extrinsic lesions causing duodenal compression are particu-larly frequent. It is important for the radiologist dealing with children to be aware of the wide variety of diseases that may involve the duodenum and their imaging characteristics.

C-808 Usefulness of inner hypoechoic band of vermiform appendix as ultrasonographic criteria for the diagnosis of acute appendicitis in children B. Kim, G. Choi, S. Kim, J. Park, K. Kim, H. Kang, K.-S. Kang; Jeju City/KR (67kbs@medimail.co.kr)

Purpose: To investigate whether the presence or absence of inner hypoechoic band in pediatric appendices may be considered an ultrasonographic criterion to exclude or confirm acute appendicitis.Methods and Materials: The appendices in consecutive 169 children with right lower abdominal pain and referred by physicians were prospectively evaluated for inner hypoechoic band in appendiceal walls. Definite diagnoses were established either with surgery and histo-pathologic examination or with clinical follow-up. The sensitivity, specificity, positive and negative predictive values, and accuracy were assessed for loss of the inner hypoechoic band as a diagnostic criterion for acute appendicitis. The student t-test was used to compare thickness of inner hypoechoic band between patients with and without appendicitis.Results: The appendices in 12 (25%) patients with acute appendicitis show entire inner hypoechoic bands and those in 36 (75%) did not. Whereas, the appendices in 97 (96%) patients without acute appendicitis shows entire inner hypoechoic bands, and those in 4 (4%) did not. The loss of inner hypoechoic band confirmed acute appendicitis with a sensitivity of 75%; a specificity of 96%; positive and negative predictive values of 89% and 90%, respectively; and an accuracy of 89%. The thickness of inner hypoechoic band in patients without appendicitis was significantly higher than that in patients with appendicitis (p=0.03).Conclusion: The visualization of entire thickened inner hypoechoic band in appen-diceal wall helps to rule out acute appendicitis. However, loss of inner hypoechoic band is suggestive of acute appendicitis.

C-809 Gastro-oesophageal reflux in paediatric patients: Evaluation with contrast enhanced ultrasound P.V. Foti, R. Farina, F. Pennisi, G. Mazzone, R. Minardi, G.C. Ettorre; Catania/IT (pietrofoti@hotmail.com)

Purpose: To prospectively evaluate the diagnostic capabilities of contrast-enhanced colour Doppler ultrasound (CEUS) in diagnosing gastro-oesophageal reflux.Methods and Materials: 120 consecutive paediatric patients (68 males and 52 females, aged 1 month-2 years) with clinical symptoms of gastro-oesophageal reflux underwent CEUS examination with an AU-5 IDEA US scanner (Esaote Biomedica) with a 3.5 MHz convex probe. US examinations were compared with twenty-four hours Ph-metry available in all patients and considered as the gold standard. The results were compared using the Mc Nemar test.Results: CEUD enabled the identification of the oesophageal tract involved in the reflux. Disease prevalence was 71.7%. CEUS showed sensitivity of 97.7% (95% CI: 94.5%-100%), specificity of 100% (95% CI: 100%-100%), accuracy of 98.3%, predictive positive value of 100%, predictive negative value of 94.4%. Statistical correlation at Mc Nemar test was high (p 0.0001). No side effects occurred.Conclusion: CEUS is a non-invasive imaging technique that allows an accurate evaluation of gastro-oesophageal reflux. Because of the lack of radiation exposure, CEUS should be used as the preferred method for diagnosis and follow-up of gastro-oesophageal reflux in paediatric patients.

C-810 Pediatric abdominal Burkitt lymphoma: The spectrum of sonographic findings at presentation M. Vakaki, G. Pitsoulakis, E. Dagiakidi, C. Koumanidou; Athens/GR (geop@hol.gr)

Purpose: To familiarize pediatric radiologists with the various sonographic appear-ances of pediatric abdominal Burkitt lymphoma (BL) at presentation, emphasizing their key-role in the prompt and proper diagnosis, with significant consequences on the BL prognosis. To the best of our knowledge, the whole spectrum of the so-nographic findings of pediatric abdominal BL at presentation is not widely known.Methods and Materials: The initial abdominal sonograms of 14 children (12 boys, 2 girls), aged 6-11 years, with histologically proven abdominal BL, were reviewed. The clinical presentation varied, though abdominal pain of various durations was the main symptom in all cases.

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Results: In 4 cases, sonography revealed significant focal, circumferential, hypoechoic, moderately vascularized intestinal wall thickening. In 2 patients, a secondary ileocolic intussusception with intestinal BL mass, acting as a lead point, was demonstrated. In 8 children with disseminated intraabdominal disease, a bulky lymphomatous mass or diffuse bowel wall infiltration, associated mesen-teric or/and retroperitoneal lymphadenopathy, ascites and hyperechogenicity of the mesentery were demonstrated. Additional findings included: enlarged kidneys with hypoechoic foci (n=3), splenic hypoechoic foci (n=2) and gallbladder infiltration (n=1). CT (n=10) confirmed the US findings and provided a better assessment of the disease stage.Conclusion: Although pediatric abdominal BL has a wide variety of sonographic appearances and definitive diagnosis relies on histopathology, the above imaging findings can strongly suggest the diagnosis. The pediatric radiologist should then request further diagnostic work-up for earlier diagnosis and initiation of appropri-ate therapy.

Pediatric

Lung

C-811 Unusual complications in “Mycoplasma pneumoniae” pneumonia in childhood C.M. Rodriguez, J.L. Vazquez, M.L. Gonzalez; Vigo/ES

Learning Objectives: Unusual complications of “Mycoplasma pneumoniae” pneu-monia such as lung abscess, pneumothorax or pneumomediastinum are critical in its management and prognosis.Background: “Mycoplasma pneumoniae” was first isolated from the sputum of a patient with atypical pneumonia by Eaton in 1944. Mycoplasmas represent the smallest self-replicating organism, in cellular dimensions and genome size, capable of cell-free existence. “Mycoplasma pneumoniae” is a common cause of com-munity-acquired pneumonia. Typically it is a disease of children and young adults with good prognosis. However, it accounts for up to 14% of immunocompetent children hospitalized for the treatment of acute community-acquired pneumonia. Occasionally, it may be complicated by adult respiratory distress syndrome, mas-sive pleural effusion and bacterial superinfection. “Mycoplasma pneumonia” is more serious in children than previously recognized and should be considered as a cause for long-term pulmonary sequelae. Histopathologically it is characterized by acute cellular bronchiolitis with edematous and ulcerative lesions of bronchial walls and alveolar infiltrates of macrophages, lymphocytes, neutrophils, plasma cells and fibrin. In severe cases, diffuse alveolar damage with fibrinous exudates and hyaline membrane formation may develop.Imaging Findings: The most common radiographic finding consists of a reticulonodular pattern and areas of air-space opacification (consolidation or ground-glass opacities). Associated features include bronchial wall thickening, atelectasis and pleural effusions. In this exhibit we show unusual complications such as lung abscess, pneumothorax and pneumomediastinum with discussion on management and clinical course.Conclusion: Prompt diagnosis and adequate management of unusual complications should improve outcome in severe complicated “M. pneumoniae” pneumonia.

C-812 Congenital chylothorax: From fetus to adolescence P. Martin, C. Gallego, A. Galindo, C. Medina, A. Hilario, M. Miralles; Madrid/ES (patricia3110@yahoo.es)

Purpose: To study the prenatal and neonatal diagnosis, imaging findings, clinical evolution and management of congenital chylothorax (CC). To define the role of radiologists in the diagnosis, assessment of neonatal period complications and follow-up. To report our experience with 32 cases of CC from 1990 to 2006.Methods and Materials: A retrospective study of a 16 year period was carried out. Thirty-two cases of CC were evaluated. We studied prenatal and neonatal diagnosis, imaging findings, management, complications and outcome, including clinical and radiological follow-up. Associated anomalies were also analyzed.Results: Thirty-two cases of CC were diagnosed. Sex ratio was 1.5:1 (female/male). Thirty patients were diagnosed prenatally. Ten infants had antenatal interventions (drainages). Twenty-four were born prematurely. Eighteen infants presented with hydrops fetalis, and 10 had syndromes and/or associated anomalies. In 26 cases, pleural effusion was bilateral. Eighteen required drainages in neonatal period. Twelve infants developed pneumothorax. At radiological follow-up, 25 patients demonstrated normal chest X-ray, 5 had increased interstitial markings and 2 remained with pleural thickenings. Four patients were diagnosed with asthma on clinical follow-up, the rest remained asymptomatic.Conclusion: The diagnosis of CC is usually made prenatally. Main associations are Down syndrome and cardiac anomalies. Pleural effusion is bilateral in most cases. The most frequent radiological complication is pneumothorax. The radiologist plays an important role in the assessment of complications, evolution and treatment since drainage can be sonographically guided if needed. There is an overall good progno-sis after neonatal survival, being worse when related to nonimmune hydrops.

C-813 Pulmonary cryptococcosis with extrapulmonary involvement in immunocompetent children: Clinical and HRCT characteristics Y. Peng, G. Sun, J. Zeng; Beijing/CN (ppengyun@yahoo.com)

Purpose: This study was to clarify clinical and HRCT characteristics of pulmonary cryptococcosis with extrapulmonary involvement in immunocompetent children. Methods and Materials: We retrospectively studied the clinical records, includ-ing host immune status, symptoms and signs, diagnostic procedures and HRCT

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characteristics in 11 immunocompetent children (7 boys, 4 girls, average age 4.7 years, range 1.7-10.2 years) with pulmonary cryptococcosis.Results: All children had normal IG and CD series. The symptom was persistent high fever with cough for at least 3 weeks. All cases exhibited extrapulmonary involvement, disseminating to liver, spleen, kidney and abdominal lymph node in 10 cases and 5/10 also had meningitis, 4/10 had cutaneous cryptococcosis; and only 1 case had complicated meningitis. A serum cryptococcal antigen (sCRAG) was positive in 11 patients. Fungal yeasts or spore was found in mediastinal node in 3 cases, liver and abdominal lymph node in 2 cases, and CSF in 4 cases. Posi-tive sputum culture or BALF was in 2 cases. The chest HRCT finding was diffuse distribution military nodules with reticular pattern mimic military tuberculosis in 4 cases, multiple nodules ( 10 mm in diameter) in 4 cases, scatter distribution solitary nodular in the subpleural area in 3 cases, consolidation in 3 cases and groud-glass attenuation in 2 cases; cavitation in 2 cases; necrotic lymphadenopathy in 7 cases, confluent to masses in 4/7 cases. Conclusion: Pulmonary cryptococcosis could occur in immunocompetent chil-dren, and is often associated with extrapulmonary involvment. A combination of HRCT finding and clinical features were very helpful to diagnosis and might imply dissemination.

C-814 Congenital diaphragmatic hernia (CDH): Monitoring of fetal lung growth with MRI after fetal endoscopic tracheal occlusion (FETO) A. Kilian1, K.A. Busing1, T. Kohl2, T. Schaible1, K. Neff1; 1Mannheim/DE, 2Bonn/DE (kristina.kilian@rad.ma.uni-heidelberg.de)

Purpose: To measure fetal lung volume (FLV) with MRI in fetuses with congenital diaphragmatic hernia (CDH) before and after fetal endoscopic tracheal occlusion (FETO) to assess its efficacy.Methods and Materials: We report the results of 5 fetuses with severe pulmonary hypoplasia diagnosed by MRI (1.5 T Sonata or Avanto, Siemens, Germany) at 24 weeks gestation. Because of their poor prognosis, all 5 fetuses underwent FETO with insertion of a balloon between 29 and 32 weeks gestation. A second, follow-up MRI was performed in 30-32 weeks gestation to estimate lung growth. FLV in fetuses with FETO was compared to lung growth in fetuses with CDH without FETO and to the expected lung volume in healthy fetuses.Results: MRI scans after FETO demonstrated an increase of FLV from a median of 8.3 ml before FETO at 24 weeks to 29.9 ml in 32 weeks. In the age-related control-group with CDH without FETO surviving children showed an improvement of FLV from 10.7 ml to 26.3 ml, the non-survivors from 6.3 ml to 8.7 ml from 24 to 32 weeks. The expected FLV in healthy fetuses rises from 32 ml at 24 weeks to 42.8 ml in 32 weeks. Four of the five children survived, one died in the postopera-tive period due to a chylothorax.Conclusion: Fetal lung growth after FETO can be successfully assessed with pre-natal MRI. In CDH fetuses treated with FETO lung growth was accelerated compared to CDH fetuses without FETO, but FLV did not reach age-related normal values.

Pediatric

Musculoskeletal

C-815 Childhood osteochondroses: A review of the clinical and imaging features J.M. O’Brien, E. Ward, O. Buckley, E. Colhoun, M. Ryan; Dublin/IE (julieM.obrien@amnch.ie)

Learning Objectives: The purpose of this pictorial review is to demonstrate and describe the imaging features of childhood osteochondroses, with discussion of clinical relevance and management of these lesions.Background: Osteochondroses are a group of diseases affecting children and ado-lescents involving bony necrosis, resorption and regeneration in the maturing skeleton. It is of paramount importance to make an accurate diagnosis because therapeutic implications may vary significantly in order to prevent any long term sequelae.Procedure Details: We interrogated our radiological database in the National Children’s hospital to review the presentation, diagnosis and outcome of the spec-trum of childhood osteochondroses. We discuss each condition in conjunction with review of the current literature.Conclusion: This pictorial exhibit focuses on the imaging appearances and clinical characteristics to elegantly demonstrate the imaging features of these conditions, thus, allowing a reliable radiological diagnosis.

C-816 The toddler refusing to weight bear: A revised imaging approach O.J. Arthurs, A.C. Gomez, P.A.K. Set; Cambridge/UK (Patricia.Set@msexc.addenbrookes.anglox.nhs.uk)

Learning Objectives: To propose a new imaging protocol for the toddler who refuses to weight bear. To increase awareness of discitis in young children in the wider imaging community. We present 3 cases of discitis where the diagnosis was delayed.Background: Lumbosacral discitis is a rare cause for toddlers (mobile young children aged 1-3 years) to refuse to weight bear. Initial radiographs and ultrasound are performed for suspected joint effusions or sepsis. There is frequently a delay in diagnosis because it is not considered or because inflammatory markers are non-specific. We review the imaging findings of this entity.Imaging Findings: At our hospital of 16,500 paediatric emergency department attendances annually, between 2004 and 2007, we identified three toddlers who presented refusing to weight bear. None had back pain or abnormal neurology, and a full range of movement of both hips was found. Two had raised erythrocyte sedimentation rates (ESR), but all other serum inflammatory markers were normal. Provisional diagnoses included irritable hip or post-viral ataxia. Radiography and ultrasound findings were unremarkable. All diagnoses were made on MRI, with two undergoing previous skeletal scintigraphy. Mean delay was 15.6 days (range 13-20) from presentation at hospital to diagnosis. All were treated with intravenous antibiotics and made a good clinical recovery. None had detectable underlying immunodeficiency or other contributing illness.Conclusion: Spinal imaging, particularly MRI, can diagnose discitis and should be suspected in toddlers who refuse to weight bear. We suggest a new imaging protocol to guide investigation.

C-817 Role of MR on vascular anomalies affecting the extremities M. Ruiz de Gopegui Andreu, M. Parrón, C. Martín Hervás, S. Morón, T. Berrocal, J.C. López Gutiérrez; Madrid/ES (mgopegui@yahoo.es)

Learning Objectives: To become familiar with current classification of vascular anomalies (VA). To illustrate MR findings of VA affecting extremities, emphasizing on key imaging features and on differential diagnoses. To describe MR indications and protocols. To expose what clinical queries the radiologist needs to know for an optimal MR interpretation.Background: VA are congenital lesions, most frequently manifested in childhood, although presentation age range may vary from birth to adulthood. Different special-ists are involved in their management, including radiologists. Terms used to describe and classify VA are confusing, especially in radiological papers. This fact may lead to an incorrect diagnosis and, therefore, an inappropriate treatment.Imaging Findings: According to International Society for Study of VA classification, specific topics will be addressed, including: vascular tumors (hemangioma, rapidly-involuting and non-involuting congenital hemangioma, tufted angioma, kaposiform hemangioendothelioma) and vascular malformations (high-flow -arteriovenous malformation- and low-flow -venous and lymphatic malformations-). Associated VA

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syndromes affecting the limbs will also be discussed (Klippel-Trenaunay, Proteus, Parkes-Weber, Maffucci, blue rubber bleb nevus, Gorham, and Bannayan-Riley-Ru-valcaba syndromes). MR-imaging and MR-angiography are the main non-invasive techniques employed for diagnosis and follow-up of these patients. Moreover, MR is used to determine the extension and hemodynamic nature of the lesions.Conclusion: This exhibit will provide a comprehensive overview of VA affecting the limbs and their current classification. MR facilitates a non-invasive, accurate diagnosis, essential for the adequate patient’s management. We will also give some understanding guidelines to the radiologist in charge of planning and evaluating VA MR images to obtain an optimal study.

Pediatric

Neuro

C-818 Intracranial meningioma of pediatrics: Manifestations in 16 patients H. Eo, J. Kim, S.-Y. Yoo; Seoul/KR (rtombow@gmail.com)

Learning Objectives: 1. Know the radiological characteristics of pediatric menin-giomas. 2. Know the atypical findings of pediatric meningiomas. 3. Know how to differentiate meniniomas from intraaxial tumors.Background: As a rare tumor of children, only a few reports deal with radiological characteristics of meningiomas and the problem remains controversial.Imaging Findings: We have analyzed images (10 CT, 16 MR images, 8 cerebral angiograms) of 16 patients with pathologically proven meningioma. Mean tumor size was 5.24 cm (range, 1.3-18.1 cm). Location of tumor was supratentorial (n=12) and infratentorial (n=4). All demonstrated a well-demarcated and enhancing mass. CT showed hyperattenuated masses in six and calcification in five. MRI demonstrated a mass with high signal intensity (SI) on T2 weighted image (WI) and low SI on T1WI in eight, a mass with iso SI on T2 and T1WI in three, and a mass with low SI on T2 and T1WI in two. Tumors were homogeneous (n=8) or heterogeneous with cystic or necrotic components (n=8). Dural attachment was seen in 11 and parenchymal edema was noted in 10. Angiography demonstrated blood supply from intracranial artery in 3 and from the extracranial artery in four patients. Preoperative diagnosis was intraaxial tumor in 7 patients. Pathologic report revealed diverse types such as transitional cell (n=4), meningotheliomatous (n=3), chordoid (n=2), fibrous (n=2), clear cell (n=1), hyalinized (n=1), and rhabdoid papillary (n=1).Conclusion: Meningiomas occur usually in children with diverse pathological types and may have atypical findings mimicking intraaxial tumors.

C-819 Analysis of MRI spectrum of brain abnormalities in infants with congenital cytomegalovirus disease: Data from an institution E. Jurkiewicz, B. Milewska-Bobula, I. Pakuła-Kosciesza; Warsaw/PL (e-jurkiewicz@o2.pl)

Learning Objectives: To illustrate the spectrum of various brain signs and ab-normalities in congenital cytomegalovirus disease (CMV) patients. To outline the advantage of the brain MR imaging. To describe results based on a series of 73 patients.Background: CMV is the most common, serious infection, which occurs in ap-proximately 1-2% of all live births. The affected patients typically are microcephalic with diminished white matter, astrogliosis, cerebral calcifications, and delayed myelination. More severe cases have lissencephaly, polymicrogyria, and cerebel-lar hypoplasia. Between 2005 and 2007, 73 infants were diagnosed and some of them were treated in our hospital. The techniques of brain imaging are described and the findings are illustrated.Imaging Findings: The MR imaging of 73 patients were retrospectively reviewed. Analysis was made of myelination pattern, cortical gyral patterns, and fpcal brain lesions. The lack of sensitivity for calcification is explainable by the basic principle of MRI. Severe brain abnormalities were found in 41 children (56.2%). The cranial MRI examinations showed the following abnormalities: lissencephaly 1 (1.2%), focal cortical dysplasia (polymicrogyria, pachygyria) 10 (13.7%), delayed myelination 9 (12.3%), white matter lesions 21 (28.8%), cystic lesions (including temporal lobes) 8 (11%), ventriculomegaly 29 (39.7%), thin corpus callosum 16 (21.9%).Conclusion: Magnetic resonance often is useful in the detection of cortical malformations, myelination delay, and cerebellar hypoplasia. MR imaging and neurological exams help to determine the diagnosis of congenital CMV disease and to introduce antiviral therapy.

C-820 Apnoea in term newborns with temporal lobe haemorrhage S.R. Hoogstraate1, M.H. Lequin2, P.P. Govaert2; 1Dordrecht/NL, 2Rotterdam/NL

Purpose: According to recent literature, lesions of the limbic system can cause apnoea. In this observational study, we determined which components of the limbic system are affected in apneic neonates with temporal lobe injury.Methods and Materials: Five term newborns are described who presented with apnoea on the neonatal intensive care unit. In all cases an EEG was registered. MRI of the brain was obtained with a dedicated neonatal coil and a MR compatible incubator. MR imaging protocol included T1- and T2-weighted sequences, a T1 gradient echo sequence and DWI.

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Results: Apnoea was induced by temporal lobe haemorrhage in all. During these apneic seizures, all neonates had focal epileptic activity on EEG. All lesions were first detected with ultrasound. On MRI, haemorrhages were located in the paren-chyma, in the subdural and/or subarachnoid space. Two haemorrhages were sur-rounded by infarction in the temporal lobe. In four cases, hippocampus and mesial temporal cortex were affected. In one newborn, only basal temporal cortex was injured. Vascular anomalies were excluded by serial MRI or serial US scanning with Doppler imaging.Conclusion: In term neonates apneic seizures can be caused by haemorrhage and/or infarction to hippocampus, mesial and basal temporal cortex. This study supports theories about the pathogenesis of apnoea in the limbic system that suggest apnoea can be caused by descending effects from the amygdala on brainstem breathing centres.

C-821 Metabolite alterations in autistic children: A 1H MR spectroscopy study B. Kubas1, J. Walecki2, E. Tarasow1, W. Kulak1, K. Kaminska2, W. Sobaniec1; 1Bialystok/PL, 2 Warsaw/PL (qbasb@interia.pl)

Purpose: The purpose of this study is to assess the role of 1H MRS in the detection of changes in cerebral metabolite levels in autistic children and to compare metabo-lite alterations to clinical status assessed by Children’s Autistic Rating Scale.Methods and Materials: Study group consisted of 14 children, aged 10-15 years. All patients matched the clinical criteria of the disease according to ICD-10; the clinical observation was not shorter than 2 years. The control group included 16 patients aged 7-15 with no clinical symptoms of the disorder and no lesions in the brain on MR studies. The MRI was performed using 1.5 T scanner, TSE (with T2 inversion) and FLAIR sequences in frontal and transverse planes. Single voxel spectroscopy (TE-35, TR-1500 msek., NEX 192) was performed with voxel (2x2x2 cm) localized in centrum semiovale, temporal lobe and cerebellar hemisphere. Spectroscopic data were analysed using the Via 2.0 C (Picker) software package. We measured ratios of NAA/Cr, Cho/Cr, mI, Glx/Cr after manual segmentation and compared with Children’s Autistic Rating Scale.Results: In metabolite concentrations, we observed significant differences in NAA/Cr coefficient in temporal lobe between the control and autistic groups. There was slight increase of Cho/Cr ratio in cerebellar hemisphere in autistic group. There was no significant difference in other metabolites. NAA/Cr ratios correlated with scores on Children’s Autistic Rating Scale.Conclusion: Metabolite alterations in autistic children suggest that HMRS may be a useful tool for characterizing regional neurochemical abnormalities in this disorder.

C-822 Intra and inter observer variability and repeatability of fetal brain sulcation assessed on MRI K. Brauer, A.D. Murray, T.W. Redpath, S. Olson, K.A. Duncan; Aberdeen/UK (k.brauer@abdn.ac.uk)

Purpose: MRI has increasingly gained popularity for assessment of fetal brain maturation. We aimed to evaluate intra and inter observer variability and repeat-ability of normal fetal brain sulcation by MRI.Methods and Materials: MRI scans were performed on a 1.5 T MR scanner in 23 patients with normal singleton pregnancies (24-39 weeks gestation). T2-weighted single shot fast spin echo images of the fetal brain were obtained in 3 orthogonal planes with research ethics committee approval as part of a study of brain devel-opment. Fetal brain sulcation was assessed based on tables by Garel: 21 primary and secondary sulci were scored as present, indeterminate or absent by two inde-pendent experienced observers, blinded to clinical information, and intra and inter observer variability assessed. Repeatability was assessed by one observer in a subset of 9 patients who each underwent 2 MRI scans on the same day. Unweighted Kappa statistics and Pearson’s correlation coefficient (R) were obtained.Results: Excellent inter and intra observer agreement (Kappa=1) was achieved when scoring the lateral, cingular, precentral, superior frontal and superior temporal sulcus, internal parieto-occipital, calcarine, interhemispheric and hippocampal fis-sure. Poor agreement was found when scoring secondary occipital and secondary cingular sulci and insular sulci (kappa -0.14-0.55; Pearson’s R 0.29-0.78). Repeat-ability was excellent except for the secondary occipital and secondary cingular sulci and insular sulci (Kappa 0.1-0.34; Pearson’s R 0.46-0.67).Conclusion: Good intra and inter observer agreement and repeatability is found when scoring fetal brain sulcation except for visualisation of secondary sulci.

Pediatric

Urogenital

C-823 Congenital abnormalities of the kidney and lower urinary tract: From genesis to imaging findings. A pictorial review M.F.R. Pires, L. Lobo, J. Inácio, J. Fonseca-Santos; Lisbon/PT (mf.pires@netcabo.pt)

Learning Objectives: To describe imaging features of renal and lower urinary tract malformations. To outline what is known about their pathogenesis. To emphasise the role of imaging evaluation in treatment and follow-up orientation.Background: Kidney and lower urinary tract malformations are increasingly de-tected on fetal ultrasound screening. They are common causes of chronic renal failure in infants/young children, but little is known about their molecular genesis. In some disorders, a genetic pathogenesis is strongly suggested by positive family history and genetic linkage studies; in others, an abnormal embryonic/maternal environment may contribute to pathogenesis. Based in animal experiments, mu-tations, teratogens, urinary tract obstruction and maternal under nutrition are the main influences that perturb urinary tract development.Imaging Findings: We describe the normal and abnormal development of the urinary tract. An overview of the imaging findings of urinary tract malformations is presented, among selected cases studied in our department. Ultrasound plays a major role in fetal screening, often allowing definitive diagnosis in post-natal evalu-ations. Evaluation by other imaging modalities, like MR, should be case-adapted.Conclusion: Malformations of the urinary tract are common causes of chronic renal failure in infants/young children. Imaging evaluation is essential to fetal screening and post-natal follow-up. Genetic pathogenesis is strongly suggested by positive family history; mutations altering gene expression during development cause some of these disorders. The understanding of the genetic aspects of human congenital abnormalities of the urinary tract may facilitate the design of genetic screening tests, allowing early diagnosis and appropriate genetic counselling.

C-824 Value of color Doppler ultrasound for the early diagnosis and outcome of neonatal renal venous thrombosis A. Hilario, C. Gallego, M. Miralles, C. Medina, P. Martin, A. Delgado; Madrid/ES (amayahilario@yahoo.es)

Learning Objectives: To describe the physiopathologic mechanisms that lead to neonatal renal venous thrombosis (RVT). To recognize initial and follow-up so-nographic features of neonatal RVT. To depict other associated findings that may increase confidence in the diagnosis report sequelae and long-term follow-up.Background: After catheter related thrombosis, neonatal RVT represents the second most common venous thromboembolic event in neonates. “Classic” di-agnostic triad consists of: flank mass, hematuria, and thrombocytopenia. Clotting process initiates at small deep intrarenal veins extending occasionally to the main renal vein. Predisposing factors (dehydration, perinatal asphyxia, shock, sepsis, etc.) produce endothelial cell damage and ischemia. Management of neonatal RVT is mainly supportive with attention to fluids, electrolytes and antibiotherapy. The benefit of prompt instauration of thrombolytic agents in preventing long-term morbidity remains unclear. Long term sequelae include glomerular disease, tubular dysfunction, hypertension, and renal scarring or atrophy.Imaging Findings: 11 neonates with RVT have been reviewed. Sonographic find-ings consisted on nephromegaly, loss of corticomedullary differentiation, diffuse hyperechogenicity and increase in the resistive index (IR) at main renal artery. Main renal vein flow could be present or absent. Additional findings included adrenal hemorrhage, intravesical clots and central thrombosis. Interlobar thrombus appears as echogenic intermedullary streaks, representing the initial phase of RVT and only persisting for a few days.Conclusion: Due to the paucity of clinical signs, the presence of some of the sonographic features described above should raise the suspicion of neonatal RVT. The presence of echogenic intermedullary streaks as initial finding is accurate and proper therapy should be instituted.

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C-825 Evaluation of pelvic ultrasonography in diagnosis and differentiation of various forms of sexual precocity in girls M. Bandouraki, A. Christoforidis, I. Economou, A.S. Dimitriadis, G. Katzos; Thessaloniki/GR (christoforidis@doctors.org.uk)

Purpose: To assess the accuracy of pelvic ultrasound variables in discriminating between normal girls and girls with sexual precocities (precocious thelarche, PT, precocious pubarche, PP and central precocious puberty, CPP) and to establish reliable cutoff limits.Methods and Materials: 88 girls with precocious puberty (23 with PT, 15 with PP and 50 with CPP) were enrolled. Additionally, 81 prepubertal girls, aged 0-10 years, served as control group. Study groups were subdivided into age intervals (0-6 years, 6.1-8 years and 8.1-10 years). All subjects underwent pelvic ultrasound scan for the determination of uterine length, uterine volume, ovarian volume and the diameter at the fundus divided by the diameter at the cervix (fundal-cervical ratio). Finally, the morphological appearance of the ovaries was assessed.Results: Patients with CPP had significantly higher values for all ultrasound vari-ables in comparison to normal girls. In turn, patients with PT and patients with PP had a similar pattern to that of normal girls, regarding pelvic ultrasound parameters. Ovarian volume seems to be the best parameter for identifying patients with CPP (a cut-off point of 3.04 cm3 has a sensitivity of 100% and a specificity of 97.1% for age interval 0-6 years). Uterine length seems to be the best parameter for distinguishing patients with CPP and patients with PT in all age groups studied.Conclusion: Ultrasonography of uterus and ovaries genitalia could serve as a complementary indication to the GnRH-stimulation test for the diagnosis of CPP and consequently the early initiation of appropriate treatment.

C-826 Voiding cystosonography for the study of the urethra C. Duran, A. Abril Valera, A. Alguersuari, E. Ballesteros, C. Martin, J. Puig; Sabadell/ES (cduran@cspt.es)

Purpose: To describe and illustrate the use of contrast-enhanced voiding cysto-sonography for the study of the urethra.Methods and Materials: 209 consecutive (127 male, 82 female) patients with sus-pected vesicoureteral reflux underwent contrast-enhanced (Levovist®, 300 mg/mL, 5%) voiding cystosonography. We used Acuson Sequoia 512 ultrasound systems with cadence contrast pulse sequencing technology, a specific imaging mode based on standard phase-inversion technology that displays a color overlay over conventional B-mode images. All scans were performed in real time (12 frame/s), using low mechanical index (0.16-0.22), and 6 and 4 MHz convex or 14 MHz linear transducers.Results: The transperineal approach was used with 14 MHz probes in 20 males. Transperineal or combined transperineal and transpelvic approaches were used with 6 MHz probes in 65 boys and with 4 MHz probes in 14 boys. Transpelvic or interlabial approaches were used in girls (6 MHz in 50 and 4 MHz in 8). The blad-der neck and entire urethra were seen in all males that were studied (n=98, mean age=14 months). Findings were normal in 95 boys, without differences 2 mm in the posterior and anterior urethra. Contrast-enhanced voiding cystosonography diagnosed posterior urethral valves (n=2), prostatic diverticulum (n=1), and anterior diverticulum (n=1), all confirmed at voiding cystourethrography. Findings were nor-mal in 58 females (mean age=27 months) with 15 cases of normal vaginal reflux.Conclusion: The image quality, ease of examination, and lack of ionizing radiation will convince professionals involved in genitourinary pathology that this technique should replace voiding cystourethrography as the diagnostic method of choice.

C-827 The role of color Doppler sonography in the detection of crossing vessels in children with pelviureteric junction obstruction M. Vakaki, A. Hountala, P. Zodiatis, E. Dagiakidi, C. Koumanidou; Athens/GR (geop@hol.gr)

Purpose: It is surgically proven that one third of operated pelviureteric junction obstructions (PUO) in children are caused by a crossing renal vessel. On the other hand, its importance remains controversial. Nevertheless, its detection at the pelviureteric junction has a case-dependent significance and is an indicator of the duration of follow-up for conservatively managed cases of PUO. To evaluate the role of color Doppler sonography in the identification of crossing vessels in children with PUO.Methods and Materials: During a 5-year period, 67 children, aged 50 days to 14 years, with surgically managed PUO were prospectively evaluated with color Doppler sonography before pyeloplasty.

Results: In 24 children, color Doppler detected a crossing vessel at the pelviureteric junction. At surgery, sonographic diagnosis was confirmed in all cases. One more case of crossing vessel, not sonographically shown, was intraoperatively identified. No false-positive color Doppler findings were noted. However, in 5 of the above cases, the crossing vessel seemed to aggravate only the obstruction, since intrinsic pathological changes were surgically found in the ureter.Conclusion: Crossing vessels were present in 37% of kidneys with PUO. The incidence of crossing renal vessel as the primary causative factor of PUO was estimated to 29% on the basis of surgical findings. Color Doppler sonography can reliably detect crossing vessels at the pelviureteric junction. This important informa-tion needs to be clinically evaluated and, thereafter, either surgical or conservative management with follow-up be decided.

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Pediatric

Vascular

C-828 Scanning method for pediatric congenital heart disease (CHD): Extremely low-dose scanning using multislice CT S. Nagaoka1, H. Obata1, T. Nakazawa1, S. Yasukochi1, M. Kanou2; 1Azumino, Nagano/JP, 2Nagoya, Aichi/JP (mcl-14@mtf.biglobe.ne.jp)

Learning Objectives: To understand the features of automatic exposure control (AEC) and the adaptive image filter (QDS). To evaluate whether extremely low-dose scanning with AEC and QDS used in combination provides an image SD equivalent to that of high-dose scanning without reducing diagnostic capabilities. To determine whether or not CT examination should be performed.Background: It is very important to acquire images with high temporal resolution and accurate 3D information when determining whether surgery is indicated in pediatric patients with CHD. Ultrasound or MRI is usually employed in such patients to avoid X-ray exposure. In the present study, CT (which provides images with high temporal resolution and 3D information) was evaluated, taking into consideration the problem of high X-ray exposure.Procedure Details: In the phantom study for optimizing scan conditions, scanning was performed using AEC and QDS with various kV, mAs, helical pitch, and slice thickness settings, and image SD was measured. The optimal scan conditions for acquiring images equivalent to those obtained by conventional methods were determined. In the clinical study, image SD was measured in 185 patients who underwent contrast CT studies with adjusted AEC and QDS, and the results were compared. In the overall assessment, image quality was evaluated visually.Conclusion: Although differences were observed depending on body size and age, the mean effective dose in 63 patients was 2.41 mSv, which is equivalent to the annual natural radiation dose (2.4 mSv). The images were judged to be suitable for diagnosis in clinical practice.

C-829 Sixty four row CT angiography: A non-invasive method for the diagnosis of pediatric cardiovascular disease M. Ulla, F. Abramzón, J. San Román, P. Marantz, R. García Mónaco; Buenos Aires/AR (ricardo.garciamonaco@hospitalitaliano.org.ar)

Learning Objectives: To illustrate the spectrum of radiological findings of 64-Multi detector CT-angiography (MDCTA) in the diagnosis of pediatric cardiovascular disease in correlation with surgical findings. To describe the advantages of this fast and non-invasive method.Background: Invasive angiography represents the gold standard method in the diagnosis of cardiovascular disease. Among pediatric population it is useful to have a non-invasive method to establish the diagnosis. Ultrafast CT-scanners allow a quick-non-invasive evaluation of the cardiovascular system, virtually eliminating

the need for prolongated sedation. In this exhibit, we communicate our preliminary experience with MDCTA in different pediatric cardiovascular diseases with surgical correlation. Our aim is to demonstrate the usefulness of MDCTA in the evaluation and diagnosis of this pathology in the pediatric population.Procedure Details: Volumetric acquisitions with a 64-row CT-scanner were performed. One ml/kg of non-ionic iodinated contrast material was injected in all of patients, except in 1 allergic patient in which gadolinium was used. The mean scanning time was 6 seconds and the mean radiation dose 5 mSv. Images were analyzed with multiplanar, volume rendering and maximum intensity projection reconstructions. The following diagnosis were made: aortic coartation, coronary artery aneurysms in Kawasaki disease, anomalous implantation of the common carotid trunk, aberrant subclavian artery, Fallot tetralogy, ascendant aortic aneurysm and a bicuspid aortic valve.Conclusion: MDCTA allowed to define the vascular anatomy for the surgeon and to achieve diagnosis in a quick and non-invasive way. The velocity of its acquisi-tions dramatically minimized sedation times, reducing potential complications in these populations.

C-830 MDCT evaluation of bidirectional carvopulmonary shunt and Blalock-Taussig shunt in pediatric patients with single ventricle: Correlation with angiography K. Choo, H. Lee, S. Sung, J. Ban, Y. Chang, J. Kim, J. Kim; Pusan/KR (kschoo0618@naver.com)

Purpose: To determine the utility of 16 slice MDCT in the evaluation of the shunt patency, stenosis and anatomic alteration of central pulmonary artery (PA) after bidirectional carvopulmonary shunt (BCPS) and Blalock-Taussig (BT) shunt in pediatric patients with single ventricle.Methods and Materials: Seventeen patients (mean age, 1.8 years) who received BCPS (n=13), BT shunt (n=4) were included. The patency, stenosis of the shunt and the anatomy of intra-pericardial PA were evaluated by 16 slice MDCT and compared by angiography.Results: MDCT accurately evaluated patency and stenosis of SVC-PA shunt, subclavian artery or innominate artery-PA shunt. In addition to size, confluence and stenosis of the central PA were well correlated with angiography findings in all patients (r= 0.90, p 0.01).Conclusion: Sixteen slice MDCT is a non invasive and useful tool for the evaluation of the shunt patency, stenosis and anatomic alteration of central PA after BCPS and BT shunt in pediatric patients with single ventricle.

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Pediatric

Miscellaneous

C-831 Imaging considerations of pediatric thyroid disease Y.-W. Chang1, H. Hong2, D. Choi1, D. Lee1; 1Seoul/KR, 2Buchoen/KR (ywchang@hosp.sch.ac.kr)

Learning Objectives: 1. Describe the embryologic and physiologic features of the thyroid gland. 2. Discuss the disease spectrum of thyroid disease in pediatrics. 3. Describe the variable image finding of pediatric thyroid abnormalities.Background: Thyroid disease is less common in pediatric patients than in adults. We review the various pediatric thyroid diseases including congenital thyroid disease and thyroid mass. We describe the conventional radiographic, gray-scale and Doppler ultrasonographic (US), nuclear medicine thyroid scan, PET-CT and MR imaging findings in children and compare these findings with laboratory and surgical findings.Imaging Findings: We reviewed embryology and physiology of thyroid gland in pediatrics. We illustrated the different pediatric thyroid diseases using various imaging modalities. These diseases included congenital hypothyroidism (dysgen-esis [aplasia; ectopy; hypoplasia], dyshormonogenesis, transient hypothyroidism), thyroglossal duct cyst, thyroiditis (suppurative thyroiditis, Hashimoto’s thyroiditis), Graves’ disease and solitary thyroid nodules (colloidal cyst, adenoma, cystic de-generative nodules, papillary carcinoma, follicular carcinoma).Conclusion: Although thyroid disease is not as common in children, but it dose occur in the pediatric patients including congenital abnormalities. Ultrasonography should be adapted as the first-line imaging examination for pediatric patients with suspected thyroid disease to provide morphologic information and the nuclear medicine thyroid scanning is a good complementary method to provide functional information of thyroid gland.

C-832 Hydatid disease in various anatomic locations in childhood: Radiological appearances M.H. Atalar, H. Egilmez, P. Erdinc, M. Isleyen, S. Bulut; Sivas/TR (mhatalar@gmail.com)

Learning Objectives: 1. Determine the location and radiological characteristics in children with hydatid disease (HD). 2. Describe the pathophysiologic features of HD and their imaging appearances.Background: In endemic regions, HD is commoner in children than in adults. In recent years, there has been frequently less diagnostic delay and, consequently, more cases of HD are likely to be diagnosed in pediatric patients because the use of noninvasive imaging modalities have become more widespread. In this exhibit, we have presented a pictorial review of the imaging features of involvement due to HD at various sites in childhood.Imaging Findings: The plain radiographs, US, CT and MRI scans of 34 pediatric cases of HD seen over a period of 6 years were reviewed. Twenty patients were girls and 14 were boys. Their ages ranged from 4 to 16 years. Imaging diagnosis was made using plain film, US, CT and MRI, and confirmed at surgery. Review of imaging of the patients demonstrated cysts in the liver (n=10), lung (n=6), perito-neum (n=4), kidney (n=3), brain (n=3), spleen (n=2), pancreas (n=1), retrovesical (n=1), heart (n=1), orbit (n=1) and soft tissues (n=2). Pathological confirmation was obtained after surgery in all cases illustrated.Conclusion: HD may occur anywhere from the big toe to the crown of the head. Radiologists, especially those who work in areas where the disease is endemic, need to be familiar with imaging findings of HD and should consider this disease in the differential diagnosis in children.

C-833 Radiation-dose reduction and improved contrast enhancement at multidetector CT (MDCT) using a low tube voltage technique Y. Yanaga, K. Awai, Y. Nakayama, Y. Funama, T. Nakaura, T. Namimoto, Y. Yamashita; Kumamoto/JP

Learning Objectives: To describe the radiation dose reduction with a low tube-voltage scan technique. To illustrate differences in iodine contrast at CT with the standard- and low tube-voltage technique. To describe clinical indications for the low tube-voltage technique.Background: As the radiation dose is proportional to the square of the tube voltage, lowering the tube voltage reduces the radiation dose. Iodine attenuation increases as tube voltage decreases because the energy in the X-ray beam moves closer to

the k-absorption edge of iodine. As lowering tube voltage decreases the amount of transmitted X-rays, resulting in increased image noise, the tube current should be increased. The capabilities of modern MDCT allow for the higher tube current that are needed with lower tube voltage settings. Adaptive noise reduction filter is also developed to compensate higher image noise.Imaging Findings: In a phantom study, the reduction from 120 to 90 kV reduced the radiation dose by up to 35% without sacrificing of low-contrast detectability and resulted in an approximately 40% increase in iodine attenuation. As the low tube-volt-age technique increased iodine enhancement, it facilitates a reduction in the iodine dose. Indications for low tube-voltage scanning are CT angiography, CT urography, and drip infusion CT cholangiography in patients weighing less than 70 kg. We will demonstrate representative cases with low tube voltage scan technique.Conclusion: Low tube-voltage scanning yields radiation-dose reduction, improved iodine enhancement, and a reduction in the iodine dose.

C-834 Lumps in the breast of children and adolescents L. Ibañez, M. Gallego, P. Diez, R. Cano, E. Salvador, E. Monedero; Madrid/ES (ephifora@hotmail.com)

Learning Objectives: To illustrate the imaging findings of the different spectrum of breast lumps in children and adolescents. To review the differential diagnosis and clinico-pathological findings of this entities.Background: Palpable breast masses arising in pediatric patients are uncommon. US and color Doppler US are helpful in the diagnosis, especially when gyneco-mastia is asymmetric, and is the ideal imaging modality to evaluate breast lesions and may be used to guide a fine needle aspiration biopsy. Most breast lesions in children and adolescents are benign, and surgery should be avoided to prevent further deformities.Procedure Details: A careful physical examination should be performed first, followed by an ultrasonographic evaluation when a suspect mass is present. Most representative imaging examples of breast masses in children are exposed: benign causes included gynecomastia, cyst, fibradenoma, lymph node, galactocele, duct ectasia, and infection. Malignant metastasis to breast is the most common malignant tumours seated at the breast of children.Conclusion: After interacting with this exhibit the radiologist will have increased knowledge of palpable breast masses in children and adolescents, including the most representative US features.

C-835 Infants of diabetic mothers: Imaging perspective I.A. Alorainy, N.B. Barlas; Riyadh/SA (alorainy@ksu.edu.sa)

Learning Objectives: To illustrate and discuss the various abnormalities and anomalies in infants of diabetic mothers and explore the role of the radiologist in early detection and participation in management of these conditions.Background: Infants of diabetic mothers are predisposed to a significantly greater risk of antental, perinatal, neonatal morbidity and mortality as well as congenital malformations. Radiologist’s role in detection, contribution in management, and follow-up of such conditions is unequivocal. Timely, accurate and proper radiological evaluation in this regard can reduce morbidity and mortality in these infants.Imaging Findings: Neural tube closure defects and holoprosencephaly are seen more frequently with maternal diabetes. Similarly, there is higher incidence of lung involvement due to hyaline membrane disease and transient tachypnea of the newborn. Several structural and functional cardiovascular abnormalities are as-sociated with maternal diabetes. Renal anomalies, adrenal hemorrhage, and renal vein thrombosis are also more common. Maternal diabetes also predisposes to bowel atresias and meconium plug syndrome as well as lower limb shortening and arthrogryposis. Caudal regression syndrome is considered the most characteristic congenital defect of diabetic embroypathy.Conclusion: Several congenital and acquired conditions are more common in infants of diabetic mothers than in other infants. Radiologists have an important role to play in early recognition and contribution in management of abnormalities and anomalies expected in these infants.

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C-836 Sonography in the evaluation of major salivary glands in childhood: A pictorial review M. Vakaki, G. Pitsoulakis, E. Dagiakidi, C. Koumanidou; Athens/GR (geop@hol.gr)

Learning Objectives: To familiarize young pediatric radiologists with the normal sonographic anatomy of major salivary glands, a prerequisite for their evaluation. To present the sonographic findings of various pediatric pathologic conditions and emphasize the role of sonography in their diagnostic approach.Background: The head and neck regions are characterized by complex anatomy. High-resolution sonography represents the initial and frequently the only imaging method for assessment of pediatric soft-tissue abnormalities in the head and neck, including major salivary glands. Knowledge of normal sonographic anatomy of major salivary glands and adjacent structures is mandatory for their evaluation.Imaging Findings: The normal sonographic appearance of major salivary glands in childhood, correlated to anatomy, is presented. The sonographic findings of vari-ous pediatric pathologic conditions affecting them are illustrated and the differential diagnosis is discussed. These entities include: acute and chronic inflammation, sialolithiasis, benign and malignant neoplasms (pleomorphic adenoma, cystic lymphangiomas, hemangioma, lymphomatous or other metastatic infiltration, etc.), HIV involvement, ranula, cysts and trauma. The indications of further imaging work-up, when needed, are highlighted.Conclusion: High-resolution sonography is very effective in the imaging study of major salivary glands in childhood. Sonographic findings alone usually suggest the correct diagnosis. In the remaining cases, they can supply significant information about the tissue characteristics of the lesion, its precise anatomic location and its effect on adjacent structures.

C-837 Imaging the diaphragm in children C. Géhanne, M. Cassart, F.E. Avni; Brussels/BE (cgehanne@hotmail.com)

Purpose: To describe the imaging techniques that can be used to image the diaphragm and to describe the diseases that affect the diaphragm in the fetus, infants and children.Methods and Materials: We will describe the imaging features of the normal and abnormal diaphragm on the different techniques used in children. Thereafter, the different diseases that affect the diaphragm will be illustrated. Emphasis will be put on the congenital and tumoral anomalies as encountered in children.Results: The main pathology that affects the diaphragm is congenital hernia. Nowadays it is usually diagnosed in utero, but it can be encountered in infants as well. The diagnostic problems and the prognostic factors will be highlighted. The other diseases affecting the diaphragm include eventration, tumors trauma and paralysis. These entities will be illustrated.Conclusion: By reading this exhibit, the viewer will be able to discuss the differential diagnosis and to understand the imaging approach.

C-838 Diagnostic value of PET/CT with contrast enhancement for the staging and restaging of pediatric tumors M.A. Kleis1, H.E. Daldrup-Link2, K.K. Matthay2, R.E. Goldsby2, E.J. Rummeny1, T. Schuster1, R.A. Hawkins2, B.L. Franc2; 1Munich/DE, 2San Francisco, CA/US (makleis@hotmail.com)

Purpose: To compare the diagnostic value of PET/CT versus PET and CT alone for staging and restaging of pediatric solid tumors.Methods and Materials: Forty-three children and adolescents with Ewing’s sar-coma, osteosarcoma, soft tissue sarcomas, lymphoma, neuroblastoma, germ cell tumor, melanoma, and squamous cell carcinoma underwent PET/CT for primary staging or follow-up imaging of metastases. The number, location and size of primary tumors and metastases were independently analyzed for the PET part, the CT part and the combined PET/CT study. These data were compared with histopathology or imaging follow-up as the standard of reference. Sensitivities and specificities were determined for each modality.Results: Sensitivities for the detection of solid primary tumors using PET/CT (95%), PET (73%) and CT (93%) were not significantly different (p 0.05). Seventeen patients had 153 distant metastases. PET/CT had a significantly higher sensitivity for the detection of these metastases (91%) than PET (37%) (p 0.05), but not CT alone (83%) (p 0.05). When lesions with a diameter of less than 0.5 cm were excluded, PET/CT (89%) showed a significantly higher specificity compared to PET (45%) and CT (55%) (p 0.05). A sub-analysis focusing on the detection of pulmonary nodules revealed a significant difference between the sensitivities of PET/CT (90%) and PET (14%) (p 0.05).

Conclusion: Sensitivities for the detection of distant metastases were significantly different between PET/CT and PET but not between PET/CT and CT. However, the specificity of PET/CT for the detection of metastases with a diameter greater than 0.5 cm was significantly increased over that of CT alone.

C-839 A systematic approach to dose optimization in pediatric digital X-ray imaging of the spine P. Brosi, R.W. Wolf; Berne/CH (Rainer.Wolf@insel.ch)

Purpose: Digital imaging still contains a vast dose reduction potential. We tried to reveal this systematically by means of a unique comprehensive quality assurance project in pediatric radiology (DoseWatchers). As an example, we demonstrate the results for spine X-rays.Methods and Materials: Two years of data collection led to a data base for further optimization of low dose diagnostics in pediatric digital imaging. Dose and image quality of the whole spine studies were analyzed and stratified to four subgroups. The primarily applied dose (group 1) was reduced in three steps: copper filtration (group 2), kV and mAs reduction (group 3) and additional lateral lead collimation (group 4). Within these four groups, we investigated the dose reduction potential by simultaneously maintaining diagnostic image quality.Results: Whole spine X-rays images represented only 3% of all expositions but were responsible for 38% of the applied dose throughout the year. With every step, a highly significant reduction (p 0.001) in dose area products in anterior-posterior as well as in lateral expositions has been achieved. In full spine imaging, the applied radiation dose can be reduced down to 10% of the original dose in anterior-posterior views and to 16% in lateral views respectively by maintaining diagnostic image quality.Conclusion: Spinal X-ray studies are still at the upper end of the pediatric dose level scale. The radiation dose can be lowered to remarkable 90% by a systematic optimization approach. Concerning the emerging digital technology, the ALARA principle is again an important issue in conventional radiography.

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Physics in Radiology

CT

C-840 Low tube voltage ‘SnapShot Pulse’ prospective electrocardiograph (ECG)-triggered coronary 64-slice CT angiography (CTA) in children and slim patients J. Horiguchi, M. Kiguchi, C. Fujioka, N. Hirai, N. Matsuura, K. Ito; Hiroshima/JP (horiguch@hiroshima-u.ac.jp)

Learning Objectives: The learning objectives are: 1. To understand high radia-tion dose in retrospective 64-slice coronary CTA in comparison with other cardiac imaging modalities. 2. To learn the mechanism of low-dose 64-slice coronary CTA using prospective ECG-triggering. 3. To know the impact of further reduction of the dose in tube voltage setting of 100 kV and 80 kV.Background: CT scan needs to keep the radiation exposure “as low as reasonably achievable (ALARA)”. ‘SnapShot Pulse’ prospective ECG-triggered coronary 64-slice CTA remarkably reduces the dose compared to the retrospective ECG-gated technique. Further reduction is possible using low tube voltage.Procedure Details: Prospective ECG-triggered 64-slice coronary CTA: Collimation configuration, acquisition technique and exposures per examination. Effect of tube voltage: 80 kV vs 100 kV vs 120 kV. Low tube voltage: increase in the photoelectric effect and a decrease in compton scattering. Indication of low tube voltage: slim (body mass index = 20 kg/m2) patients with a body height = 170 cm or patients within standard body mass index (around 25 kg/m2) with a body height 150 cm, i.e. mostly younger patients.Conclusion: 1. Retrospective 64-slice coronary CTA is associated with high dose (up to 20 mSv), while prospective coronary CTA with low dose (around 3 mSv). 2. Radiation dose varies with the square of the kilovoltage, i.e. 120 kV to 80 kV leading to a reduction of the dose by 56%. 3. Prospective 64-slice coronary CTA with a tube voltage of 80 kV results in an effective dose of around 1mSv. 4. Able to maintain satisfactory signal-to-noise ratio despite low tube voltage.

C-841 How to optimize image quality and reduce overall patient population dose in MDCT cardiac imaging J. Li, W. Qi, X. Du; Beijing/CN (jianying.li@med.ge.com)

Learning Objectives: Describe an effective method for automatic tube current (mA) selection in CT coronary artery (CTA) imaging to obtain desired and consistent image quality for patients of different sizes.Background: Currently most CTA scans use fixed mA independent of patient sizes that create uneven image quality and sub-optimized dose distribution to patients. Patient BMI-dependent mA selection method is relatively easy to use but still lacks accuracy due to patient attenuation variation with same BMI. We propose a method to accurately determine mA to produce consistent and physician-specified image quality for patients of different sizes. This method is based on noise analysis on images obtained with timing bolus (TB) scans.Procedure Details: We first established the correlation between the image noises of TB and CTA scans at fixed mA. This correlation was then converted to form a formula to determine the patient-dependent mA for getting a physician-specified CTA image noise for individual patient before the CTA scans. The required tube current mA (req) can be expressed and determined using the measured TB image noise N (b), the mA used for the TB scans and the desired CTA image noise N (c) for the same patient.Conclusion: We have developed a novel method to accurately determine the required mA for CTA to obtain a desired and consistent image quality across patient population using noise analysis from timing bolus scans. This method has been tested clinically and is robust and easy to use to optimize radiation exposure to patients.

C-842 Artifacts in CT: The mechanism and the methods of avoidance J. Kim; Goyang-si/KR (misojsk@dreamwiz.com)

Learning Objectives: To understand why CT artifacts occur and how they can be prevented or suppressed.Background: Artifacts can seriously degrade the quality of CT images and some-times they mimic lesions. Spiral CT improves speed performance that acquires volume images in a short exposure time. It has offered a true 3D imaging ability and thus provided new applications such as CT angiography. But artifacts as con-ventional CT still exist in spiral CT such as beam hardening artifacts and sampling

artifacts. In addition, partial volume artifacts are exaggerated in spiral CT because of slice sensitivity profile degradation. To optimize image quality, it is necessary to understand why artifacts occur and how they can be prevented or suppressed.Procedure Details: In this presentation, we review the types of CT artifacts by grouping the origins of CT artifacts into four categories: (a) physics-based artifacts; (b) patient-based artifacts; (c) scanner-based artifacts; and (d) helical and multisec-tion artifacts. And it will be described with regard to the mechanisms by which they are generated and the methods to suppress them.Conclusion: With this exhibition, comprehensive understanding of various CT artifacts can lead to the knowledge of how they can be prevented or suppressed and to optimize image quality.

C-843 Anatomy and physiology of multi-channel CT: What a radiologist needs to know N.N.N. Naguib, N.A.N. Mohammed, T.J. Vogl; Frankfurt a. Main/DE (nagynnn@yahoo.com)

Learning Objectives: To give a simplified idea about the technology behind multi-slice CT (MSCT). To explain the principles of isotropic imaging, pitch, anatomical coverage and radiation dose in terms of the MSCT technology.Background: Ever since its introduction in the form of a dual-channel CT in 1993, MSCT became a strong competitor to MRI, opening new horizons in the use of CT and introducing new applications that were not known before. For a radiologist, physics represents a learn on demand subject i.e. as long as he does not need to know it he does not try to learn it, but in our opinion understanding the technology and physics behind a machine enable us to manipulate it to our needs, pushing it to its maximum limits and sometimes beyond those limits allowing the introduction of new uses and applications.Procedure Details: The terminology and definition of MSCT will be introduced. Then an explanation of the detector array design and image formation will be given (including Z-Sharp technology) with reference to the differences in detector design between the 4 major manufacturers of MSCT. Then the principle of isotropic imaging and its effect on 3D and MPR will be explained. Following will be the new definition of pitch in terms of MSCT. The anatomical coverage and the effect of gantry rotation time on it will be given. Finally, the subject of radiation dose will be discussed.Conclusion: Understanding the technology and physics of MSCT enable us to make the maximum use of it.

C-844 Achieving consistent image quality and dose reduction for MDCT coronary artery imaging with body mass index adapted tube current selection G. Wang, J. Gao, J. Li, N. Li; Beijing/CN (jianying.li@med.ge.com)

Purpose: To evaluate the clinical value of a body mass index (BMI) adapted tube current (mA) selection method for obtaining consistent image quality and dose reduction for patient population in MDCT coronary artery imaging.Methods and Materials: The relationship between patient BMI and required mA to achieve desired image quality was established using the control group (CG) of 100 MDCT cardiac patients (BMI 19 to 33) with standard scan protocol of fixed 640 mA. We then scanned 100 more patients (SG) with BMI-adapted mA to achieve desired noise level of 27 HU. We recorded the CTDIvol and CTA image noises from the two groups. Two experienced radiologists quantitatively evaluated the image quality using scores of 1-4 with 4 being the highest.Results: The image quality scores were 3.56 0.54, 3.57 0.63, respectively, for CG and SG groups, with no statistical difference. For CG using fixed mA, image noise and BMI had strong linear relationship, while for SG the image noise was independent of patient sizes averaged around 26.7 HU with smaller image noise deviation than the fixed mA group (3.86 HU vs. 5.66 HU). The t-test indicated statistically significant lower dose (15%) with BMI-adapted mA method due to the use of lower mA for smaller patients (p 0.01).Conclusion: We have proposed a quantitative BMI adapted mA selection method to accurately determine the required mA for individual patients. This method is robust and practical for obtaining consistent image quality for different cardiac patients and provides dose reduction for smaller patients compared to the use of a fixed mA.

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C-845 CT-AEC image characteristics for sharp changes in X-ray absorption (step characteristics) I. Aizawa, Y. Muramatsu, K. Yokohama, F. Shimizu, T. Tanaka; Chiba/JP (teamcoo13099@yahoo.co.jp)

Purpose: Sharp changes in X-ray absorption, e.g. at the lung apex or superior margin of the liver, strongly affect image quality when scanning with CT-Automatic Exposure Control (CT-AEC). We investigated the image characteristics of CT-AEC for sharp changes in X-ray absorption (step characteristics).Methods and Materials: The XYZ AEC with an image quality setting function installed in an Aquilion 16M system (16 DAS, Toshiba, Japan) was used. A phantom simulating the plane containing the superior margin of the liver (stepped phantom: 200 mm + 250 mm, Kyotokagaku, Japan) was set at the rotation center. Scan-

ning was performed with the image quality setting fixed to SD 12.0, image slice thickness fixed to 5 mm, scan direction set to IN/OUT, pitch factor (PF) changed in three steps (0.6875, 0.9375, 1.4375), row slice thickness changed in three steps (0.5, 1.0, 2.0 mm), and scan start position changed in 1-mm increments. Variations in image noise (distance and height) were measured.Results: Image noise changed sharply (1-mm slice, PF0.9375: distance 42 mm, height SD 6.3-12.4) between the slices before and after the plane where the phan-tom diameter changed (point 0), regardless of the scan direction. The change was greater for higher PF values and larger X-ray beam widths (2-mm slice, PF1.4375: distance 69 mm, height SD 6.1-13.1). The pattern of changes varied periodically with the scan start position.Conclusion: The scanning parameters significantly affect the step characteristics of CT-AEC. Understanding the step characteristics is essential when analyzing clinical images containing sharp changes in X-ray absorption.

C-846 Image noise reduction based on wavelet transform maxima for CT image M. Ikeda1, R. Hitomi1, K. Imai1, M. Matsumoto1, A. Fujiwara1, S. Wada2; 1Nagoya/JP, 2Niigata/JP (a40495a@nucc.cc.nagoya-u.ac.jp)

Purpose: For CT images, we have evaluated the noise reduction effects of the method based on wavelet transform maxima, by comparing with the wavelet thresholding methods, such as the spatially adaptive one. This image denoising method was devised by Mallat et al. and is implemented by the following: detection of modulus maxima of the edge detection wavelet transform of CT image, selec-tion of the modulus maxima corresponding to positive Lipschitz exponents (these maxima can be considered to represent image components except for noise), and image reconstruction of the selected modulus maxima.Methods and Materials: The denoising method was evaluated with the chest phantom scanned by a 16-detector-row helical CT scanner; these CT images were acquired at a tube voltage of 120 kVp and at 5, 10, 20, 50, 70, 100, 140, 150, and 250 mAs, reconstructed with the three different reconstruction kernels, and four polymer tubes filled with water placed on the chest phantom were used for the noise evaluation.Results: The noise SD of the noise-reduced image was approximately proportional to the value of mAs, as well as the original image. Further, the noise SD of the image denoised by the method based on wavelet transform maxima was smaller than that by the spatially adaptive and uniform thresholding methods by using the soft-threshold and translation-invariant method and Daubechies wavelet with two vanishing moments.Conclusion: Experimental results showed that the image denoising method based on wavelet transform maxima eliminated the more noise on CT images, compared with the wavelet thresholding methods.

C-847 An anthropomorphic, cardiovascular flow phantom for CT contrast and imaging protocol optimization J.F. Kalafut1, C.A. Kemper1, S. Sammett2; 1Indianola, PA/US, 2Columbus, OH/US (jkalafut@medrad.com)

Purpose: We present a novel flow phantom that mimics the mammalian cardiovas-cular circuit for the purpose of refining imaging and contrast application techniques. Pulsatility is introduced, hemodynamics can be adjusted and maintained within physiologic limits, and the dynamic motion of the coronary tree is life-like.Methods and Materials: A commercial, ventricular pump acts as the system’s heart. The pump was modified so that a triggering signal is generated at the end of systole and modifies the R-R interval of a commercial ECG simulator interfaced to a MSCT scanner. An off the shelf coronary tree model (Shelley medical) emulates human cardiovascular anatomy. Reservoirs and compliant tubing comprise the rest of the

flow circuit. The model is calibrated so the central fluid volume can be set between 3 and 8 L. The cardiac output can be adjusted from 2.5 L/min to 8 L/min.Results: Multiple applications of contrast material into the phantom were conducted during acquisition with a 64 slice CT scanner. We demonstrate the linearity of re-sponse by injecting contrast protocols with durations of 5, 10, 15 and 20 seconds and superimposed the time-enhancement curves generated from an ROI drawn in the ascending aorta. We demonstrate a linear correlation between pump-cardiac output and contrast enhancement identical to that in humans and porcine models. The flow-phantom also demonstrates the feasibility of a model-predictive control strategy.Conclusion: An anthropometric, dynamic flow model of the mammalian cardio-vascular system is useful as an analogue of a human or animal for the purpose of optimizing CT angiography technique.

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C-848 How to use ECG mA modulation to reduce radiation dose in cardiac imaging: Consideration and experience summary J. Liao1, L. Liu2, Y. Shen1, J. Li1; 1Beijing/CN, 2Kunming/CN

Learning Objectives: To introduce the principle and method of ECG mA modu-lation in cardiac scan. To illustrate the consideration and experiences in clinical application.Background: The radiation dose is relatively high in cardiac helical scan (20-25 mSv) compared with other CT scans. ECG mA modulation is a useful technique to reduce dose through setting normal mA at the end of diastole phase while lower mA at the other phases. This technique could provide excellent coronary artery image and not affect cardiac function measurement and reduce 30% dose at least. In this exhibit, we will describe the consideration in using this technique, such as available heart rate, the effect of heart rate fluctuation, the mA and phase window setting and the selection of reconstruction algorithm.Procedure Details: 1. Reduce patient’s heart rate ( 75 bpm). 2. Setting the maximum and minimum mA according to patient's BMI (Body Mass Index). 3. Setting phase window of maximum mA according to heart rate fluctuation. 4. After scan, reconstruction with different algorithms to improve image quality. 5. Reformat coronary artery image at the end of diastole phase and take function analysis using the images at all phases.Conclusion: ECG mA modulation is a prospective gating technology that could reduce 30-50% radiation dose in cardiac imaging. The image quality degrades with the increase of heart rate fluctuation ( 10 bpm); optimized maximum mA width and multi-sector reconstruction could improve the low signal artifact.

C-849 Evaluation on the influence of ECG mA modulated on image quality and exposure dosage of CT cardiac scan with fluctuant heart rate Y. Yan1, S. Yun2, X. Jianrong1; 1Shanghai/CN, 2Beijing/CN (yinyan1034@163.com)

Purpose: To decide whether the ECG modulated current will effectively reduce the exposure dosage by making use of the cardiac phantom.Methods and Materials: The cardiac pulsating phantom was set at 60 bpm as the basal heart rate; then the test was divided into 6 groups according to the fluctuant heart rate. The phantom was scanned when the ECG modulated current was turned off, and the exposure dosage of each scan sequence was documented. The model of MDCT instrument was BrightSpeed Elite, GE Medical Systems. The quality of images was divided into 4 classes. Then the ECG modulated current was turned on; meanwhile, according to the different ECG modulated current parameter, four groups were established. The CT scan was performed repeatedly and the images were carried on the same measurement. The results from the 5 groups with and without ECG modulated current were analyzed by the SPSS10.0.Results: Statistical analysis showed no significant difference among the SNR and the quality of the images from the 5 groups when the heart rate was fluctuant. The exposure dosage was remarkably reduced when the ECG modulated current was on. Furthermore, there were apparent significant difference among the different ECG modulated current parameter groups. If the heart rate fluctuation was up to 15 bpm, the exposure dosage would increase obviously.Conclusion: Scanning the heart with 16-slices spiral CT, the application of ECG modulated mA can effectively reduce the exposure dosage without sacrificing the image quality even if heart rate was fluctuant.

C-850 Organ dose evaluation of in-vivo micro-CT N. Buls, I. Willekens, J. de Mey; Jette/BE (nico.buls@uzbrussel.be)

Purpose: Health effects from extended serial X-ray exposures that are associated with in-vivo micro-CT scans could become a significant factor in animal cancer studies because experimental outcomes such as animal survival or tumor growth may be altered. The purpose of this study was to evaluate radiation organ doses to mice from micro-CT scans with two methods.Methods and Materials: Organ doses were measured on a dual tube micro-CT scanner (Skyscan 1178) with scan resolution 83 μm, 50 kV, 0.615 mA, 121 s acquisition time and no table movement. Healthy euthanized C57bl/6 mice (n=5) were packed with 15 individually calibrated lithium fluoride thermoluminescent dosimeters (TLD-100). TLDs were placed in the following organs: lungs, liver, stomach, spleen, colon, bladder and subcutaneous tissue. Also the CTDI100 was

measured with a 100 mm ionization chamber, centrally positioned in a 2.7 cm diameter water phantom.Results: Internal TLD analysis demonstrated a median mouse organ dose of 5.46 0.6 mGy per mAs or 40.6 4.4 cGy per single scan. The CTDI100 measured in the water phantom was observed to give a comparable result of 6.56 mGy per mAs. The largest organ dose (6.81 mGy/mAs) was absorbed by the subcutane-ous tissue.Conclusion: Animal cancer studies have demonstrated tumor growth inhibition associated with the organ dose levels observed in this study. Inter-organ dose variation appears to be small; results suggest that dose optimization studies could be performed with the use of only a few TLDs or a CTDI ionization chamber, which is usually available in a radiology department.

C-851 Audit of radiation dose during coronary MSCT angiography: A comparative study of different scanning protocols D. Shao, H.-W. Ling, X. Lin, Y. Liu, K. Chen; Shanghai/CN (shaodd@126.com)

Purpose: To evaluate effects of tube voltage and current on radiation dose and image quality during noninvasive coronary angiography with MSCT.Methods and Materials: One hundred and twenty-four consecutive subjects underwent ECG-gated MSCT for coronary angiography. All cases were randomly classified into three groups according to their scanning protocols: tube voltage and current of group1 are 140 kV and 380 mA, group2 are 120 kV and 400 mA, and group3 are 120 kV and 340 mA. Image quality was assessed based on image noise, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and diagnostic segment accessibility. All image-quality parameters were compared statistically using one-way analysis of variance.Results: The effective dose of three groups were 19.8 1.8 mSv, 15.7 1.7 mSv and 12.4 2.1mSv, respectively (P 0.001). The reduction in effective dose was associ-ated with a diminution in diagnostic image quality as assessed by the image noise (P 0.001). There was no significant difference in CNR and SNR between groups. Interestingly, the diagnostic segment accessibility in group2 (79.55%), which was the highest one among the three groups, was significantly greater than that in the group3 (71.43%) (P=0.005); however, there was no significant difference between group1 (77.42%) and group2 (P=0.376).Conclusion: The balance between optimal dose and maintained diagnostic, rather esthetic for coronary CT angiography investigation, is necessary. Optimization of scanning protocol might be beneficial to limit radiation exposure while the diagnostic segment accessibility remained acceptable.

C-852 Development of pediatric CT protocols to obtain minimal doses in PET/CT studies: A physicist’s approach W. Nordhøy, M. Sheikhaeri, A. Larsen, O. Glomset; Oslo/NO (wibeke.nordhoy@radiumhospitalet.no)

Purpose: To develop minimal dose pediatric CT protocols on a PET/CT-scanner. The images must allow for identification of relevant anatomy and provide adequate attenuation correction for PET.Methods and Materials: Starting from a pediatric protocol supplied with the scan-ner, four new whole-body protocols were created corresponding to different body weight classes. Homogenous cylindrical perspex phantoms with diameters 10, 16 and 32 cm were models of different body sizes, and the standard deviation of the CT-number in a ROI was used as a measure of noise. A reference noise level was established from images obtained with an adult protocol using the large phantom. For selected tube voltages, the tube current was reduced as far down as permitted by the scanner to approach the same noise level as the reference.Results: For a tube voltage of 80 kV, the noise was reduced by 59 and 29% for the medium and small phantoms, respectively, compared with the noise of the reference. The patient doses were reduced by 50-87% depending on the body weight. The images obtained with the modified protocols had adequate quality and the dose may be further reduced without loss of important anatomical information.Conclusion: For the smallest children the CT dose could be reduced to such a level that it contributes to only around 10% of the total patient dose.

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MR

C-853 Artefacts at high-field MRI G.J. Kraus, W. Drahanowsky, S. Robinson; Vienna/AT (krausgj@hotmail.com)

Learning Objectives: To illustrate artefacts that are more pronounced at high-field MRI (3 T). To explain how these artefacts are generated and to discuss how they can be minimized.Background: Some artefacts that might be negligible at lower field strength (1.5 T) are more pronounced at higher field-strength (3 T). Examples are artefacts due to lowered magnetic susceptibility (unshielded iron, air, chemical-shift artefacts, metallic implants), dielectric effects, motion- or truncation artefacts which are seem-ingly more pronounced. New techniques such as parallel imaging can be applied to overcome or decrease some of those artefacts. The imaging appearance of artefacts is described and illustrated.Imaging Findings: We present examples of reduced magnetic susceptibility such as cavernomas and metallic implants, dielectric effects, motion- and truncations artefacts and flow-related artefacts.Conclusion: There are clear benefits of high-field MRI (3 T) such as higher signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR). Studies can be accomplished faster and there is better spatial resolution compared with lower field-strength (1.5 T). However, some artefacts that are negligible at lower field-strength can be much more pronounced at higher magnetic field-strength. For some of those artefacts, various compensation techniques can be applied.

C-854 Whole-body magnetic resonance imaging: Techniques and clinical applications E. Onur, M. Seçil, A.Y. Göktay, M. Manisalı, D. Özaksoy, O. Dicle; Izmir/TR (mustafa.secil@deu.edu.tr)

Learning Objectives: To present the technical details of the whole-body magnetic resonance imaging (MRI) and whole-body magnetic resonance angiography (MRA) along with clinical indications and findings based on medical cases.Background: Assessment of hematologic diseases involved over multiple organs and bone, detection and staging of the metastases of multi-organs, assessment of patients with metastases without a known primary tumor and assessment of the diseases indicating diffuse bone marrow infiltration in the childhood are the application areas of the MRI. Atherosclerotic occlusive disease, Takayasu arteritis and aortic aneurysm are among the most common clinical indications of the MRA. In this study, technical aspects and our clinical experience about the whole-body MRI and MRA are presented.Procedure Details: Whole-body MRI and MRA are performed using a 1.5 Tesla MR equipment (Gyroscan Achieva, Philips Medical Systems, Netherlands). The whole body is scanned in the largest field-of-view (FOV) of the six sequential regions with STIR, T1 TSE, T2 TSE sequences in the coronal plane. For MRA, the images are obtained after rapid injection of contrast agent and the entire arterial system is scanned in the largest FOV of the four sequential regions. After transferring the images to the workstation, they are merged to obtain the whole-body image. The original and produced images can be processed with no resolution loss.Conclusion: Utilizing a moving tabletop, a table extender and software enables whole-body MRI and MRA in a short period of time. The non-invasive and the non-ionizing nature of these techniques make them practical and efficient.

C-855 Principles of k-space sampling P. Paolantonio, R. Ferrari, M. Rengo, P. Lucchesi, F. Vecchietti, A. Laghi; Latina/IT (paolantoniopasquale@hotmail.com)

Learning Objectives: To describe the principles of k-space sampling. To offer an easy explanation of k-space physics for the radiologist. To describe the properties of k-space and to illustrate different K-space sampling strategies. To show how dif-ferent portions of K-space contribute to the final image appearance. To illustrate the rationale for centric, elliptic, spiral and partial k-space sampling strategies.Background: K-space sampling represent a crucial step in MR image acquisition. The easy way to sample K-space is represented by a sequential mode that is also a time-consuming procedure. K-space sampling strategy may be modified in order to reduce acquisition time. A central or elliptic sampling of K-space is recommended for contrast-enhanced-MR-angiography in order to collect the central line of k-space during the peak of vessel enhancement.

Procedure Details: We show in step-by-step form the image generation process, focusing our attention on k-space sampling. We will describe how k-space is sampled in several pulse sequences that are commercially available. Using graphic examples, we will describe different k-space sampling strategies.Conclusion: The knowledge of k-space sampling strategies is crucial for under-standing the MR image acquisition process. Several k-space sampling strategies are available. The use of the appropriate k-space sampling strategy is of value in reducing acquisition times and in optimizing image acquisition for the clinical purpose of MR-studies, like that in centric or elliptic sampling of k-space and contrast-enhanced MR-angiography.

C-856 Do you really know what is inside your MR scanner? Advanced anatomy of the magnet for young residents and adult radiologists M. Anzidei, A. Napoli, B. Cavallo Marincola, C. Zini, P. Di Paolo, C. Catalano, R. Passariello; Rome/IT (mikilgenio@hotmail.com)

Learning Objectives: 1. To provide a basic description of the fundamental hardware available on the most diffuse MR scanners. 2. To correlate each hardware element with its peculiar imaging-related function and effect. 3. To illustrate the more ad-vanced technical features available and their current and potential applications.Background: More than any other imaging technique, MR requires an extensive knowledge of the hardware performance and of its influence on examination quality. The excellence of imaging protocols always relies on the radiologist’s skill to exploit the best performance out of the equipment.Procedure Details: This exhibit reviews the function and influence on imaging of each basic component of an MR scanner: 1. the Magnet; 2. shielding and shimming apparatus; 3. gradients; 4. coils; 5. injectors; 6. new toys including tilting tables, dedicated coils and interventional-MRI dispositives.Conclusion: Knowing the basic anatomy of a MR scanner is part of the fundamen-tals for each radiologist, radiology resident and technician, but an in-depth look at our technology may help to obtain advanced performances from each hardware piece. This exhibit displays from A to Z, the available hardware in the field of MRI, with a glance on the newest features in the market.

C-857 Overview of current testing methods and standards for magnetic resonance safety and compatibility of medical devices G. Schaefers; Gelsenkirchen/DE (schaefers@mrcomp.com)

Learning Objectives: Safety and compatibility, relevant interactions of medical devices in the MR environmentBackground: MR safety and compatibility are internationally recognized. The ASTM standard F2503 provides MR marking requirements. FDA, European and international guidance documents and standards contain requirements to test implants (coils, stents, PFOs, etc.) and accessory devices to be tested for the MR environment.Procedure Details: Magnetic displacement forces must be measured to determine the magnitude and risk. Magnetic torques align an implant in the magnetic field. Both interactions can be assessed via ASTM F2052 and F2213 standard testing methods. Radio frequency (RF) induced heating: RF pulses (MHz) apply the main amount of energy. This topic is multi-parameter dependent. Properties like electric conductivity, dimension, configuration, etc. have to be considered (e.g. overlapping stents, pacemaker leads and so on). ASTM F2182 provides a basic test method. Computer simulation of the specific absorption rate and temperature distribution assists in heating testing. RF pulses and switched gradients can induce voltages in conductive structures. Test methods are under development by IEC/ISO. Safe functioning is a concern of passive and and active medical devices, and thus must undergo individual testing.MR artifacts can void diagnostic relevant information. The magnitude should be included in device marking from ASTM test method F2119.Conclusion: Comprehensive investigations of MR interactions are necessary. MR test methods for force, torque, RF heating and MR artifacts exist. Standardized MR testing of implants minimises patient risk, provides comprehensive safety marking to the MR user and guides manufacturers in device development.

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C-858 Spatial factors for quantifying constant flow velocity in a small tube phantom: Comparison between phase-contrast cine MR imaging and intraluminal Doppler guidewire H. Machida1, Y. Komori1, E. Ueno1, Y. Shen1, K. Okajima1, M. Fujimura1, M. Hirata1, S. Morita1, K. Suzuki1, S. Kojima1, M. Sato1, T. Okazaki2; 1Tokyo/JP, 2Aichi/JP

Purpose: Quantifying coronary flow velocity using MR imaging is useful for noninvasively assessing the functional severity of coronary artery stenoses. How-ever, spatial factors affecting accurate measurement have not been thoroughly investigated. We examined spatial factors influencing MR constant flow velocity measurements in a small tube phantom, using those measurements by intraluminal Doppler guidewire as a reference.Methods and Materials: We generated constant flow velocities from approximately 40 to 370 cm/sec in a tube of 4-mm diameter; quantified the spatial peak flow ve-locities of a single pixel and of five pixels adjacent to one another and the spatial mean velocities within regions of interest in the cross-section of this phantom using segmented k-space, phase-contrast cine MR imaging on different pixel dimensions of 1.0 × 1.0 to 2.5 × 2.5 mm; and compared these measurements with the temporally averaged Doppler spectral peak velocities.Results: We found excellent linear correlation between the spatial peak flow veloci-ties of one pixel by MR imaging and those by Doppler guidewire (r .99: MR flow velocity for pixel dimensions 1.0 × 1.0 mm = 1.013x + 13.70 cm/sec). However, MR measurements were significantly underestimated according to Bland and Altman analysis, applying spatial peak velocities of the five adjacent pixels using pixel dimensions of 1.67 × 1.67 to 2.5 × 2.5 mm and mean velocities on all pixel dimensions.Conclusion: Sufficiently high spatial resolution allows accurate MR measurement of constant flow velocity in a small tube at spatial peak velocities of one pixel.

C-859 2004/40/EC directive: Characterization of diagnostic room electromagnetic environment due to radiological activities M. De Marco, S. Maggi; Ancona/IT (black_dragon@libero.it)

Purpose: In April 2004, the European Union has issued the 2004/40/EC directive which states minimum requirements for the protection of workers against exposure to electromagnetic fields (EMF). Considering that EMF are ubiquitous and not only confined nearby a RM site, we present an analysis of some diagnostic room environments (CT, US, NM, Thoracic) where workers may be exposed to electric and magnetic fields potentially higher than the general public. Compliance with exposure limits is also checked and verified.Methods and Materials: We measured low frequency EMF strength close to chest detector, gamma-camera gantry, power supply cabinets, CR reader and in the places where personnel usually stands attending and positioning a patient. Electric and magnetic fields have been collected for a 2 min period, and then they have been averaged and rounded off.Results: Data obtained show that electric field ranges from 2.7 V/m (near the multi-plate CR reader and fluoroscopic monitor) to 6.5 V/m (Gamma camera gantry), to 7.5 V/m (operator’s console). Magnetic field ranges from 0.05 to 0.15 μT accordingly to the different activities described above. The measurement uncertainty caused by systematic errors can be quantified in: indicated_field_strength 10%. The DAV limits indicated in the directive are 10 V/m and 0.5 μT, respectively.Conclusion: In recent years, there has been an increasing public concern about the possible risks for human health due to the exposures to electromagnetic fields. Our research has given no evidence that low frequency electromagnetic radiation emitted during radiological activities exceed the action values reported in the directive.

C-860 Assessment of different image reconstruction methods for DCE-MRI F. Knoll, R. Stollberger, F. Ebner; Graz/AT (florian.knoll@tugraz.at)

Purpose: The reliable identification of pharmacokinetic parameters requires high resolution DCE-MRI data sets in spatial and temporal domains. High field systems in combination with undersampled imaging techniques like parallel imaging have the potential to deliver those images. It is, however, not clear to which extent these techniques change the time course of contrast enhancement, in particular, for the arterial input function. This work evaluates the performance of five imaging methods.Methods and Materials: A software phantom was designed to simulate the change of contrast during the passage of a contrast agent bolus in different regions, includ-

ing arterial and tumor tissues. Sequence parameters were TR=3 ms, TE=1.2 ms, FA=25°, Matrix Size=128x128x20. Image reconstruction was performed with GRAPPA (R=4, ACS=32, delta t=3.42 s), tGRAPPA (R=4, ACS=32, delta t=1.92 s), HYPR (HYPR frame: 16 projections, composite: 128 projections, delta t=0.96 s), PROBER (R=4, ACS=32, delta t=3.42 s) and TRICKS (delta t=2.63 s). An unac-celerated scan with the same sequence parameters had a delta t of 7.68 s.Results: The time course of the signal intensity showed deviations in HYPR, TRICKS and tGRAPPA reconstructions. Most artifacts were visible in GRAPPA and tGRAPPA. The mean value of the pharmacokinetic parameter K_trans (ml/min 100 g) was evaluated in the region of tumor tissue (true value in the simulation: 42.3, GRAPPA: 53.90, tGRAPPA: 53.33, HYPR: 55.71, PROBER: 53.21, TRICKS: 57.94, unaccelerated scan: 110.70).Conclusion: Undersampled imaging techniques provide the temporal resolution for pharmacokinetic analysis. Especially the performance of HYPR was surpris-ingly good as this method normally exploits sparsity in the image, which was not the case in this simulation.

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Miscellaneous

C-861 What is the most effective indicator for estimating the maximum radiation dose to the patient during percutaneous coronary intervention procedures? K. Chida, Y. Kagaya, K. Fuda, Y. Morishima, H. Saito, S. Takahashi, S. Yamada, M. Zuguchi; Sendai/JP (chida@mail.tains.tohoku.ac.jp)

Learning Objectives: 1. To discuss the indicators for estimating the maximum radiation dose to the patient’s skin (MSD) in percutaneous coronary intervention (PCI) and understand the advantages/disadvantages of these indicators. 2. To show how to estimate the MSD in PCI. 3. To demonstrate the importance of estimating the MSD in real-time to reduce the radiation injury risk in PCI.Background: Many cases of skin injury caused by excessive radiation exposure during PCI procedures have been reported. However, real-time maximum-dose monitoring of the skin is unavailable for many PCI procedures.Procedure Details: We investigated the relationship between the MSD and several indicators (dose-area product; DAP, patient’s weight, fluoroscopic time, weight × fluoroscopic time: WFP, and patient’s total entrance skin dose: TESD) in PCI pro-cedures, separately analyzing the relationships for different target vessels.Conclusion: The major teaching points of this exhibit are as follows: 1. No feasible method for measuring the MSD in real-time is available for PCI; therefore, the MSD is estimated using several indicators. 2. The DAP and WFP can be used to estimate the MSD during PCI in the right coronary artery but not in the left coronary artery, especially the left anterior descending artery. 3. The TESD, such as the dose at the interventional reference point, is a very useful real-time indictor of the MSD during PCI. 4. Present knowledge can apply not only to PCI, but also to other types of IVR, and offers useful information for managing the radiation dose during all IVR.

C-862 The twinkling body: A pictorial guide to all possible anatomical locations of the colour Doppler twinkling artifact A. Nunziata, O. Catalano, P.P. Saturnino, F. Sandomenico, S. Paoletta, A. Siani; Naples/IT (tonikus@libero.it)

Learning Objectives: This exhibit illustrates many different locations of the colour-Doppler ultrasound twinkling artefact, stressing the practical interest of its recognition.Background: The colour- and power-Doppler US twinkling artefact is encountered at some hyperechoic regions, especially when the strongly reflecting structure has a granular surface and is composed of individual reflectors.Imaging Findings: Twinkling artefact is a changing mixture of red and blue colour behind hyper reflecting media. We show images where the twinkling artefact was due to: renal stone disease, ureteral stones, gallbladder stones, salivary gland stones, calcifications and stone due to chronic pancreatitis, gallbladder stone and cholesterolosis, parenchymal calcifications, intratumoral calcifications, athero-sclerotic plaques, soft-tissue foreign bodies, intraocular foreign bodies, catheters, and sutures.Conclusion: Recognition of the twinkling artefact has several practical applica-tions. Barely visible ureteral stones (renal colic!), salivary duct stones and foreign bodies may become evident because of the twinkle at colour-Doppler scanning. Characterization of renal stones chemical composition has been described. Knowl-edge of this artefact may avoid images misinterpretation. For example, twinkling at carotid plaque may simulate plaque ulceration while intratumoral twinkling may mimic intralesional flow.

C-863 Color Doppler twinkling artifact in various conditions during abdominal ultrasonography: Pearls and pitfalls H. Kim, D. Yang, W. Jin; Seoul/KR (khcppp@lycos.co.kr)

Learning Objectives: To describe the mechanism of color Doppler twinkling artifact and various ultrasonographic machine factors influencing the appearance of the artifact. To illustrate the various conditions associated with the twinkling artifact and its added diagnostic value. To demonstrate pitfalls of twinkling artifact as a diagnostic sign.Background: Color Doppler twinkling artifact manifests itself as a rapidly alternating red and blue color signal behind a strongly reflecting structure, and close vertical bands with no outer wrapping in the spectral Doppler mode. The twinkling artifact is dependent on various settings of ultrasonography machine including focal zone,

gray scale gain, color write priority, and pulse repetition frequency. The twinkling artifact has been associated with calcifications in various tissue, urinary calculi, biliary stone, encrusted indwelling urinary stents, gallbladder adenomyomatosis, and bile duct hamartomas.Imaging Findings: In this exhibit, we will describe the mechanism of color Dop-pler twinkling artifact and ultrasonographic machine factors influencing it. We will illustrate the various conditions displaying the twinkling artifact, highlighted in the hepatobiliary and urinary systems. We will also demonstrate some conditions of pitfall in using the twinkling artifact as a diagnostic sign.Conclusion: Color Doppler twinkling artifact is an additional useful ultrasonographic sign in the diagnosis of calcified lesion, urinary and biliary stone, gallbladder ad-enomyomatosis and some miscellaneous conditions.

C-864 Pulsating cardiac phantom and coronary flow phantom on the multi-modality cardiac study: Overview and history from over 10 years of experience in phantom development and phantom experiments Y. Shen, J. Liao, J. Li; Beijing/CN (yun.shen@med.ge.com)

Learning Objectives: The purpose of this exhibit is to learn/understand the types of pulsating cardiac phantom and coronary flow phantom and to understand the applications based on over 10 years of experience in phantom development and phantom experiment.Background: Cardiac MR/MDCT is of great interest in the diagnosis of cardiac function/coronary stenosis. The pulsating cardiac phantom and coronary flow phantom are very useful in multi-modality cardiac study.Procedure Details: 1. History of cardiac coronary phantom development and phantom experiment. 2. Phantom types for multi-modality cardiac study: Normal/compact pulsating cardiac CT phantom, specially pulsating cardiac CT phantom with PC control, pulsating MR/CT cardiac phantom, cardiac coronary phantom with stent/in-stent restenosis/stenosis/soft plaque/calcification plaque, MR coronary flow phantom. 3. Application of cardiac phantom: Evaluation of cardiac image quality, evaluation of cardiac application.Conclusion: 1. Pulsating cardiac phantom was started from single helical CT generation. 2. The cardiac phantom is useful in evaluating the cardiac CT/MR technology. 3. The cardiac phantom is very useful in evaluating multi-modality for cardiac study with the same condition. 4. Pulsating cardiac phantom could be a basic tool in maintaining cardiac CT performance.

C-866 FP-CIT brain SPECT data: Description of a semi-quantitative analysis method E.M. Covelli, E. Tedeschi, P. Sullo, M. Salzillo, G. Mazzarella, G. Belfiore; Caserta/IT

Purpose: Parkinson’s disease is characterized by a progressive decrease in dopa-minergic nigrostriatal neurons and motor symptoms. Analysis of data is a two step process: visual inspection of data available from the video output of the computer system is followed by quantification of that information.Methods and Materials: The brain FP-CIT application allows quantification of regions of interest on a composite image of the transverse slice set of a brain SPECT study. Next we added ROI and drew a large bihemispheric occipital region on the composite image; then drew 3 ROI on the LEFT brain side on the striatum, caudatum and putamen. We then proceeded to automatically mirror these regions to the right side of the brain and dragged to obtain the optimal position. The selection generated the asymmetry index numbers. The average counts in the occipital, left and right striatum, caudatum and putamen regions were calculated by dividing the total counts by the number of pixels in each region.Results: In one year, we studied 219 patients with suspected Parkinson’s disease, 56 of these (25%) had a normal tracer distribution in the bilateral striatum, without significant background or asymmetry index. In contrast, all other patients had an abnormal distribution pattern with a high striatum/background ratio and an asym-metry index 10%.Conclusion: This easy method is designed to study tracer uptake changes in the basal ganglia by evaluating compromised presynaptic transporters in PD patients. It also helps convert subjective data into objective data for follow-up and treatment response.

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C-867 Refraction-enhanced tomosynthesis of joints by X-ray dark-field imaging D. Shimao1, T. Kunisada2, H. Sugiyama3, M. Ando4; 1Inashiki-gun/JP, 2Okayama/JP, 3 Tsukuba/JP, 4Noda/JP (shimao@ipu.ac.jp)

Purpose: In order to acquire tomograms of joints by refraction-based X-ray dark-field imaging (XDFI), the shift-and-add tomosynthesis algorithm is introduced and its feasibility is investigated.Methods and Materials: We performed our experiments at the vertical wiggler beamline, BL14B, of the Photon factory in KEK. The XDFI system was composed of the asymmetric cut Bragg case collimator and the symmetric cut Laue case analyzer. The incident X-ray energy was tuned to 36.0 keV. The object was an intact proximal interphalangeal joint (PIPJ) amputated from a cadaver. Only the refracted component of incident X-rays can pass through the analyzer. Raw projec-tion data were acquired by the XDFI in a total of 11 views through an angle of 10° in 1° increments. The X-ray dose for one piece of raw projection data was set to one-eleventh of that for one standard projection image by the XDFI. Appropriately shifted raw projection data were added to produce arbitrary tomograms parallel to the fulcrum plane.Results: We obtained a clear XDFI tomogram of PIPJ including the articular cartilage, extensor digitorum tendon, and a minute crack in the subchondral bone surface without an increase in the X-ray dose. The crack was revealed only on the XDFI tomogram while articular cartilage and the tendon were observed even on the standard projection XDFI.Conclusion: Refraction-enhanced tomosynthesis by XDFI can reveal articular cartilage and a minute abnormality in the subchondral bone surface so that it could be useful for early image diagnosis of joint diseases.

C-868 Reference levels at European level for cardiac interventional procedures R. Padovani1, E. Vano2, K. Faulkner3, A. Trianni1, C. Bokou4, A. Dowling5, O. Dragusin6, J. Jankowski7, V. Tsapaki8, J. Vassileva9; 1Udine/IT, 2Madrid/ES, 3Newcastle/UK, 4Luxembourg/LU, 5Dublin/IE, 6Leuven/BE, 7Lodz/PL, 8Athens/GR, 9Sofia/BG (padovani.renato@aoud.sanita.fvg.it)

Purpose: Interventional cardiology is a medical specialty widely known to deliver high radiation doses to patients, who may receive, in some complex cases, skin doses over the threshold for deterministic effects. Because several studies have demonstrated large variability in delivered doses, SENTINEL group has assessed European reference levels (RL) as a tool to reduce dose variability and aid in the optimisation of radiation protection.Methods and Materials: A European survey, performed in 9 European centres, investigated doses in selected cardiac procedures: coronary angiography (CA), percutaneus transluminal coronary angioplasty (PTCA) and electrophysiology, collecting data on nearly 2,000 procedures.Results: All examined doses or dose analogues exhibit a large variability. The examinations have been pooled and RL assessed as the 75° percentile of distri-butions. Proposed European RL for kerma-area product (KAP) are: 45, 85 and 35 Gycm2, for effective dose: 8, 15, 6 mSv, for fluoroscopy time: 6.5, 15.5 and 21 min, respectively for CA, PTCA and diagnostic electrophysiology procedures. Because equipment performance is one of the factors contributing to patient dose variability, RL for entrance air kerma for fluoroscopy and image acquisition measured at the entrance of a 20 cm PMMA phantom are also proposed: 13 mGy/min and 100 microGy/image, respectivelyConclusion: The study confirms the presence of a large variability of patient doses across Europe and the need of a set of European RL as a tool for the optimisation of radiation protection (SENTINEL Euratom Research contract No. 012909).

C-869 Half-value layer measurement using a radiochromic film for QA and QC T. Gotanda1, T. Katsuda2, R. Gotanda1, A. Tabuchi1, M. Eguchi1, S. Takewa1, Y. Takeda1; 1Okayama-city/JP, 2Himeji-city/JP (tat151826@yahoo.co.jp)

Purpose: Although it is considered that the half-value layer (HVL) of the diagnostic X-ray is important for quality assurance (QA) and quality control (QC), constant monitoring has not been performed because ionization chamber dosimetry is time-consuming and complicated. To verify the applicability of GAFCHROMIC XR TYPE R (GAF-R) film to the measurement of HVL instead of monitoring the ionization chamber, the calibration curve using a single-strip method to measure the HVL was evaluated.Methods and Materials: The calibration curves of absorbed dose and film density were generated using the single-strip method with 8 strips of GAF-R. The single-strip method precisely evaluates film density increment. The exposure parameters of the

X-ray generator (KXO-50G) were 120 kV, 200 mA and 0.28 sec. Absorbed doses ranged from 0 to 12 cGy in increments of 2 cGy. The coefficient of determination of the straight-line approximation was evaluated. The HVL values measured using the GAF-R and the ionization chamber (Radcal-1015 6 cc) methods were compared.Results: The coefficients of determination of the straight-line approximation for 8 pieces of GAF-R ranged from 0.9903 to 0.9961. The HVLs (effective energy) of GAF-R and ionization chamber were 5.30 mm (43.88 keV) and 5.47 mm (43.20 keV), respectively. The differences in HVL and effective energy values were 3.2 and 1.6%, respectively.Conclusion: The calibration curve of each GAF-R strip indicated a similar straight line. It was suggested that GAF-R was able to measure HVL using only film density growth. GAF-R is available for HVL measurement without an ionization chamber.

C-870 Development and integration of correction methods in a vendor-independent flat-detector CT image reconstruction platform Y. Kyriakou, R.M. Lapp, D. Prell, M. Meyer, C. Niebler, W.A. Kalender; Erlangen/DE (yiannis.kyriakou@imp.uni-erlangen.de)

Purpose: To provide a flexible and vendor-independent image reconstruction sta-tion for flat-detector CT (FD-CT) with a wide range of artifact correction algorithms within the framework of OrthoMIT.Methods and Materials: An image reconstruction platform was developed which is able to process flat-detector raw-data. It uses a Feldkamp-type reconstruction algorithm including parker weighting supporting partial scans. The software package integrates a multitude of pre and post-processing correction algorithms. Cupping correction is provided for pre-correction of polychromatic data. To avoid misalign-ment and truncation artifacts, respective correction algorithms were implemented and integrated into the workflow along with an effective scatter suppression based on physical scatter modelling which was included. Artifacts near metallic implants are handled by a new raw-data based metal artifact removal algorithm combined with multi-dimensional adaptive filtering. In an exemplary test setup using a C-arm FD-CT system (Axiom Artis, Siemens Medical Solutions, Forchheim, Germany) we evaluated the performance of the reconstruction platform with respect to its integration ability and image quality.Results: Image reconstruction times of 1-2 min for a 512³ volume from about 500 projections were achieved on a standard PC hardware including region of interest reconstruction. The cupping and scatter correction methods allowed for homoge-neous images, whereas metal artifacts were reduced. The built-in DICOM services provide a seamless integration into the clinical and/or intraoperative workflow in a heterogenous hardware environment.Conclusion: The developed vendor-independent reconstruction platform meets the need for an efficient, fast and extensible system that can be used for multiple applications in the intraoperative FD-CT workflow.

C-871 Color Doppler twinkling artifact in intrauterine fetal demise A. Ozkur, E. Dikensoy, S. Kervancioglu, R. Kervancioglu, S. Inaloz, M. Bayram; Gaziantep/TR (ayhanozkur@yahoo.com)

Purpose: To determine whether twinkling artifacts on color and power Dop-pler sonography could be used as a new sonographic sign of intrauterine fetal demise (IUFD).Methods and Materials: In this prospective study, 24 consecutive pregnant women with IUFD were included after fetal sonographic examinations. Sonographic examination included gray-scale, color, power, and spectral Doppler imaging. The sonograms were then analyzed for the presence, appearance, and intensity of the twinkling artifacts.Results: Twinkling artifacts on color Doppler were observed in all of the 24 IUFD as a rapidly changing color Doppler signal complex associated persistently with different parts of the fetal body. The artifacts were localized especially in the neck, back, and iliac regions. Artifact intensity correlated with the time elapsed since death.Conclusion: Twinkling artifact was noted in all dead fetuses on color, power, and spectral Doppler examinations. Thus, the observation of these artifacts may be considered as a new sonographic sign of fetal demise, which may reflect the time elapsed since death.

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C-872 Effect of anode-filter materials on noise equivalent quanta of a computed radiography system for mammography M. Buades-Forner, A. Cámara-Turbí, A. González-López, B. Tobarra-González; El Palmar (Murcia)/ES (manuelj.buades@carm.es)

Purpose: To evaluate the effect of anode and k-edge filter materials on the noise equivalent quanta function (NEQ) of Konica Minolta RP-6M image plates (IPs) used in mammography.Methods and Materials: IPs (43.75 μm pixel size) were characterized at 28 kVp, Mo/Mo, Mo/Rh and W/Rh with 2 mm added aluminium filtration. NEQ was computed from the presampled modulation transfer function (MTF) and the normalized noise power spectrum (NNPS), measured according to IEC 62220 standard. A tungsten edge was placed at 6 cm from the chest wall. NNPS was analyzed from a 6 x 6 cm2 region centered on previous point. An entrance surface air kerma of 75 μGy was used. Average glandular doses (DGM) to a 45 mm PMMA phantom were calculated for each anode/filter. To reach the same Mo/Mo DGM, IPs were also exposed at 92.4 (Mo/Rh) and 113.6 μGy (W/Rh).Results: At exposure of 75 μGy, DGM were 1.6, 1.3 and 1.05 μGy for Mo/Mo, Mo/Rh and W/Rh, which means a reduction on DGM of 19% and 35% for Mo/Rh and W/Rh compared with Mo/Mo. NEQ is higher with both Mo/Rh and W/Rh; im-provement is larger at 0.5 mm-1 (5 and 15.5%, respectively) and diminish at high frequencies (1% at 7.0 mm-1 for both beam qualities). When DGM=1.6 μGy, the increase of NEQ is 20% (Mo/Rh) and 70% (W/Rh) at 0.5 mm-1 and 12.5% (Mo/Rh) and 33.5% (W/Rh) at 7.0 mm-1.Conclusion: The use of Mo/Rh and W/Rh provides a dose saving and/or better image quality in CR mammography.

C-873 Needle image plates (NIP) compared to powder image plates (PIP) at same dose in routine digital radiography: A retrospective study W. Hey, A. Kleinholz, R. Temmen, W. Kersjes; Ludwigsburg/DE (HEYWO01@kliniken-lb.de)

Purpose: To evaluate if there is a significant difference concerning detail resolution (assessed visually), overall quality and diagnostic value in routine CR using needle image plates (NIP) compared with powder image plates (PIP) at same dose.Methods and Materials:: In this retrospective study 216 radiographs (bones, thoraces, abdomen) of 96 patients performed with NIP were matched concerning body region, age and sex with 216 radiographs performed with PIP. The images were rated double-blind (1[excellent] to 4[poor]) for detail resolution, overall qual-ity and diagnostic value by three experienced radiologists independently. The differences of the averaged ratings were tested for statistical significance with the Mann-Whitney U test.Results: There was a small, but highly significant (<0,001) difference in all three parameters in favour of the NIP system (detail resolution: 1,13 vs 1,45; over-all quality: 1,31 vs 1,60; diagnostic value: 1,54 vs 1,82, averaged values).Conclusion: Our data indicate a small, but very consistent superiority of the NIP system compared to PIP concerning detail resolution, overall quality and diagnostic value. Considering the already very satisfying results with PIP images, our results suggest the use of NIP systems rather to reduce dose than to increase image quality.

Radiographers

CT

C-874 Cardiac computed tomography with 64-slice technology for the detection of heart diseases: Technical aspects, applications and limitations A. Plotas1, A.N. Chalazonitis2, S. Lachanis2, F. Laspas2, P. Porfyridis2, G. Neofitou2, M. Kelogrigoris2, N. Ptohis2; 1Korinthos/GR, 2Athens/GR (red-rad@ath.forthnet.gr)

Learning Objectives: 1) To understand the technical principles and represent the radiation dose from CT of the heart. 2) To describe the cardiac and great vessel anatomy. 3) To illustrate multislice computed tomography features of different heart diseases. 4) To represent the limitations and pitfalls of the method.Background: Multislice computed tomography has different applications in the evaluation of heart diseases; however, the main advantage of this technology is the noninvasive imaging of the coronary arteries. Over the past 30 years, invasive cardiac catheterization has been the gold standard method for the visualization and detection of coronary stenosis. The recently developed 64-slice computed tomography scanner generation provides promising results in the assessment of coronary artery disease.Imaging Findings: In our exhibit we will in detail describe the technical aspects, the cardiac and great vessel anatomy and the most common congenital and acquired heart diseases. We will also present multislice computed tomography angiography for detection of coronary artery stenosis, assessment of coronary bypass grafts and evaluation of coronary stent patient. Finally we will represent the main limitations that remain, in spite of technological advances.Conclusion: The images of 64-slice have excellent temporal and spatial resolution and techniques to decrease noise are being evaluated. Thus, the future of computed tomography of the heart is very promising and expectations are that this technology will play an ever-increased role in cardiac imaging.

C-875 Clinical values of dose reduction techniques in 64-row MDCT coronary artery J. Gao, G. Wang, J. Li, X. Sun, N. Li, W. Zhao, R. Dai; Beijing/CN (jianying.li@med.ge.com)

Purpose: To evaluate the dose reduction potentials and clinical values of using various dose reduction techniques in 64-row MDCT coronary artery imaging.Methods and Materials: 100 patients who underwent cardiac scans using 64-row MDCT were divided into normal dose (ND) and low dose (LD) groups of 50 each with similar body habitus. The LD group was scanned with combinations of dose reduction techniques offered on the system, including cardiac bowtie, adaptive filter C2, and ECG mA modulation with cardiac phase of 40-80%. The CTDIvol values were recorded and image noises were measured for the two sets. Two experienced radiologists quantitatively evaluated the image quality blindly using scores of 1-4 with 4 being the highest. We performed statistical analyses on the quality scores, noise measurements and effective doses from the two sets.Results: Image quality scores and noises were 3.56 0.54, 27.54 4.52 and 3.62 0.57, 27.30 6.15 for the ND and LD groups, respectively, with no statistical difference (p 0.05). However, the effective doses for ND and LD groups were 17.96 1.71mSv and 8.75 0.83mSv, respectively, with p 0.01 indicating statisti-cally significant lower dosage (51% in our study) with the use of the combined dose reduction techniques.Conclusion: The use of combined dose reduction techniques on 64-row MDCT can effectively reduce overall radiation dose to patients based on the CTDI mea-surements without adverse impact on image quality and other clinically relevant parameters. Radiation dose can further be reduced with tighter cardiac phase selection for the ECG mA modulation and patient-dependent mA selection.

C-876 Scanning techniques with CT-AEC (step characteristics of CT-AEC and respiration control) I. Aizawa, Y. Muramatsu, K. Takahashi, Y. Maie, T. Tanaka; Chiba/JP (teamcoo13099@yahoo.co.jp)

Purpose: In CT-Automatic Exposure Control (CT-AEC) with an image quality setting function, tube current is modulated based on a positioning image. Image quality may decrease in regions with significant respiratory motion or sharp changes in X-ray absorption (e.g., superior margin of the liver). We analyzed image quality near the superior margin of the liver to optimize scanning technique.

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Methods and Materials: A phantom simulating a plane containing the superior margin of the liver (Stepped phantom: 200 mm + 250 mm) and a standard chest phantom (LSCT phantom) were scanned with CT-AEC. Variations in image noise (distance and height) for the specified SD were measured. Routine scan conditions for scanning with CT-AEC were used (XYZ-AEC, SD 12.0). Misalignment of the superior margin of the liver between positioning and axial images was measured in 138 cases.Results: Stepped phantom: image noise changed between the slices before/after the plane where the phantom diameter changed (point 0), but the SD was not exceeded in most cases (1-mm slice, PF0.9375: distance +21 mm to -23 mm, height SD 6.3-12.4). LSCT phantom: image noise was almost constant (1-mm slice, PF0.9375: SD 9.7 0.9) in the slices before/after the superior margin of the liver ( 50 mm). Average misalignment between clinical axial and positioning im-ages was 8.6 mm.Conclusion: XYZ-AEC with an image quality setting function adjusts the tube cur-rent to maintain image quality even with sharp changes in X-ray absorption. With respiratory motion, image quality may decrease in approximately 8% of patients, suggesting the importance of breathing instruction.

C-877 Breathhold trial prior to multislice CT coronary angiography to determine optimal scanning parameters F. Engelken, M. Dewey; Berlin/DE

Purpose: The scanning parameters used in multislice computed tomography (MSCT) coronary angiography should be adapted to the patient’s heart rate. The usefulness and clinical feasibility of a breathhold trial prior to MSCT coronary angiography for measurement of the patient’s heart rate in order to determine the optimal scanner settings (gantry rotation time and pitch) was investigated.Methods and Materials: MSCT coronary angiography using 64*0.5 mm detector collimation was performed in 218 patients. Prior to MSCT examination, a breathhold command was given, after which a software plugin recorded the patient’s heart rate from an electrocardiogram over the expected scanning time and determined optimal scanning parameters based on this information. The success rate in predicting optimal parameters for the subsequent MSCT examination as well as the image reconstruction window width as a measure of temporal resolution was analysed.Results: Optimum scanning parameters were selected by the software in 179 of 218 cases (82%) despite a small increase of 1.4 beats/min (bpm) in the mean heart rate during the examination compared with the breathhold trial (65.9 vs. 64.5 bpm, p=0.002). The median image reconstruction window width achieved in this group was 174 ms (range 100-200 ms), compared to 192 ms (range 149-225 ms) in cases where suboptimal settings were selected (p 0.001).Conclusion: The breathhold trial and the use of the automated software tool are convenient and allow selection of optimal CT parameters in over 80% of patients. The procedure appears to be a useful adjunct to optimise temporal resolution in MSCT coronary angiography.

C-878 Image quality and optimal image reconstruction interval for non-invasive coronary angiography with dual-source CT G. Bastarrika1, J.C. Pueyo1, M. Arraiza1, C.N. De Cecco2, B. Zudaire1, A. Villanueva1; 1Pamplona/ES, 2Rome/IT (bastarrika@unav.es)

Purpose: To prospectively evaluate the relation of heart rate (HR) and image quality and determine the optimal reconstruction interval for coronary arteries in dual source CT (DSCT) exams.Methods and Materials: Coronary CT angiography studies from 28 consecutive patients with variable heart rates between 49 and 107 bpm who underwent cardiac DSCT exams were analyzed. Images were reconstructed over the whole cardiac cycle in 5% steps (0-95% of R-R). Two readers independently assessed image qual-ity with regard to the diagnostic evaluation of right (RCA), left anterior descending (LAD) and circumflex (Cx) arteries for the assessment of coronary artery disease on a four point grading scale (1= not evaluative, 4= no motion artifacts).Results: Mean overall image quality was 2.84 0.35 for LAD, 2.84 0.39 for Cx, and 2.83 0.36 for RCA. There was no correlation between mean HR and overall image quality for all coronary arteries (p 0.01). Optimal reconstruction intervals were found to be 70% for LAD and Cx in the majority of cases (19/28 and 18/28, respectively) and 40% (12/28) and 70% (13/28) for the right coronary artery. Cor-relation between optimal reconstruction interval and HR was statistically significant (LAD: -0.57, Cx: -0.44, RCA: -0.58, p 0.01). Optimal reconstruction interval was 40% for all coronary arteries in patients with HR 80 beats per minute.Conclusion: Cardiac imaging with DSCT provides robust image quality of coronary arteries independent of the HR. Best image quality was obtained in diastole with HR less than 80 beats per minute and in systole with faster HR.

Radiographers

MR Imaging

C-879 Measuring metastaic liver lesions on MRI examinations: What the radiographer should know I. Mokali, M. Mantatzis, K. Amarantidis, D. Theodorakis, S. Voulgaridou, S. Kakoklyris, P.K. Prassopoulos; Alexandroupolis/GR (jmokali@gmail.com)

Learning Objectives: To describe linear and volumetric methods for measuring metastatic liver disease (MLD) on cross-sectional imaging. To familiarize radiogra-phers with measuring techniques on liver MRI. To present technical requirements and optimal MR sequences for measuring MLD and to discuss difficulties and pitfalls in the measuring process.Background: Quantification of MLD on imaging examinations is fundamental for monitoring the patients under chemotherapy treatment.Procedure Details: Forty four consecutive patients with first diagnosed MLD underwent MRI prior to treatment initiation, in the middle and immediately after the completion of chemotherapy. Conventional T1-WI, T2-WI, dynamic post-gado-linium enhanced T1-WI obtained at 20’’, 60’’ and 180’’ and post-SPIO enhanced T2 and T2* images were acquired. Unidimensional measurements of the maximal diameter of the five larger lesions, according to RECIST criteria, and volumetric measurements of these lesions summing all lesions’ slice volumes, were performed on both gadolinium and SPIO-enhanced images on a Centricity workstation. The confluence of lesions when increasing in size, splitting of lesions to smaller ones and lesions that became less than one cm in diameter may interfere with the ac-curacy of measurements on serial MR examinations. Unidimensional and volumetric measurements resulted in kappa coefficient of 0.74 concerning response-partial response-stability-progression of MLD on follow-up examinations.Conclusion: Unidimensional or volumetric measurements of MLD on serial MRI examinations should be provided to the referring physician for monitoring each patient’s response to treatment. The radiographer should be aware of the principles and techniques to accurately obtain these measurements in close collaboration with the radiologist.

C-880 Tips and tricks for MR arthrography: How dynamic manouvers can improve diagnosis C. Martínez Guillamón, I. Camarasa Fernández, E. Rico Sandoval, C. Garcia Llopis, E. Llopis Sanjuan; Alzira/ES (carmartinez@hospital-ribera.com)

Learning Objectives: MR arthrography is a well-established diagnosic tool for subtle intra-articular derangements. The aim of this exhibit is to present some tricks, especially dynamic manoeuvres, which together with conventional imaging might outline some joint derangement and improve diagnostic skills.Background: Efficacy of MR arthrography depends mostly on an adequate intra-articular injection. However, some easy tricks before entering the MRI suit, as well as an exquisite selection of coil and sequences are essential to obtain good and diagnostic images. Although MR arthrography is the method of choice, for some specific joint diseases, it is becoming increasingly apparent that static images do not always outline lesions. Therefore, we describe some positions that help to depict the injury or distinguish anatomic variants.Procedure Details: 1. Hip: Manual traction followed by load during MR procedure permits differentiation between femoral and acetabular cartilage. 2. Knee arthrog-raphy: Passive and active movements and suprapatellar bandage permit the improvement of diluted contrast in the meniscal space. 3. Ankle: Manual traction to separate talus and tibial surfaces. 4. Shoulder: Besides the classic ABER posi-tion, forced external rotation, compared to internal rotation, demonstrates superior compartment and biceps labral complex better.Conclusion: Radiographers together with radiologist might, with small tricks, using an exquisite MRI technique and dynamic manoeuvres, improve image quality and therefore diagnostic ability.

C-881 Breast cancer staging with breast MRI I. Camarasa Fernández, E. Rico Sandoval, C. García Llopis, C. Martínez Guillamón, J. Paris Bueno; Alzira/ES (icamarasa@hospital-ribera.com)

Learning Objectives: To describe our MRI technique in the staging of patients with breast cancer.Background: Breast cancer staging implies gathering of information not only on tumor size, but also on the presence of multifocality, multicentricity, bilaterality,

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extensive intraductal component and extension to the nipple-areola complex. Breast MRI has been proven to modify the therapeutic approach in 20-24% of the cases. In our hospital, 452 patients were evaluated, with a change in therapeutic approach of 20.4%. Attention to technical details is essential for the correct diag-nosis of these patients.Procedure Details: Patient is introduced in a prone position, head-first. Both breasts are adjusted with cotton pads to the dedicated breast coil. Our standard breast MRI protocol is as follows: dynamic volumetric T1 TSE sequence (1.0 mm thickness/0.0 gap) in the coronal plane with a 3D aquisition. The first sequence is acquired previous to the administration of endovenous contrast (Gd-DTPA, 0.1 mmol/kg and a 15 cc bolus of saline) and thereafter we program the following five sequential acquisitions, which start simultaneously with contrast injections. The second sequence is a T2 TSE sequence (2.5 mm thickness/0.0 gap) in the coronal plane that encompasses both axillary regions. The third sequence is a T2 TSE sequence in the axial plane (2.5 mm thickness/0.0 gap) that enables further evaluation of both axillary regions.Conclusion: Breast MRI has proven very useful due to its impact on the therapeutic approach. We present our standard technique, which has been validated through comparison of MRI findings with pathology results.

C-882 MR angiography of the circle of Willis in the assessment of patients with aneurysms treated with embolization E. Rico Sandoval, C. Garcia Llopis, I. Camarasa Fernández, C. Martínez Guillamón, A. Revert Ventura; Alzira/ES (erico@hospital-ribera.com)

Learning Objectives: To review the necessary preparation for the patient who undergoes an MR angiography study. To depict the anatomical details of the circle of Willis. To show our MR angiography technique for the study of intracranial vessels and our results compared to digital angiography in 90 patients.Background: MR angiography is capable of showing with exquisite detail the findings of patients treated with embolization of the circle of Willis, sparing these patients additional radiation from repeated CT scans.Procedure Details: A standard head study is performed with an added specific survey for MR angiographic studies. We plan the sequence 3D inflow (TOF), first performed without contrast enhancement and later with 3 ml of Gd-DTPA in order to compare both sequences and show possible turbulences and slow flow in intracranial vessels. We show the most frequent anatomical variations of the circle of Willis that should be taken into account in order to identify the aneurysms correctly and examples of these aneurysms. We present the artifacts generated by embolization materials that should be known in order to differentiate them from other technical artifacts.Conclusion: Knowledge of anatomical variations and technical pitfalls in the study of the circle of Willis in patients treated with embolization is of outmost importance in order to plan the study correctly. MR angiography enables identification of a greater number of aneurysms’ necks and of partially treated aneurysms.

C-883 Lateral position imaging method in lumbar vertebrae MRI examination K. Kazama1, M. Kimura2, M. Tsurumaki1, M. Sekiya2, D.-Y. Tsai2; 1Tainai/JP, 2Niigata/JP (kazakiyo@zpost.plala.or.jp)

Purpose: In general, lumbar vertebrae MRI examination is performed with the patients in the face-up position. However, it is difficult for the patients who are suf-fering from intense lumbago and lower melagra to maintain the face-up position during the examination. In this study, we propose a MRI imaging technique for lumbar vertebrae examination without medicine dosage by using lateral positioning instead of the commonly used face-up positioning.Methods and Materials: Between June 2000 and March 2007, fifty patients (21 males and 29 females, age ranged 32-86 years, mean age 65), complaining of intense lumbago and lower melagra and being unable to lie down in the face-up position, underwent MRI examination with lateral positioning. A 0.2 T MRI of per-manent magnet opening type (Signa GE) with a 9-inch GP (general purpose) coil was used. The GP coil was set at the right angle with respect to the MRI gantry and was in contact with the back of the patients.Results: All patients tolerated well the entire examinations performed with lateral positioning. Also, we were able to maintain examination throughout without caus-ing any delay of examination. Moreover, valuable image information for accurate diagnosis can be obtained from the 50 patients who were suffering from disk hernia, lumbar spinal canal stenosis or compression fracture.Conclusion: Our results show that MRI examination may be performed in the lateral position instead of in the face-up position, when the patients are suffering from intense lumbago or lower melagra.

Radiographers

Miscellaneous

C-884 Evidence-based medicine meets radiology A.N. Chalazonitis1, J. Tzovara1, G. Tsimitselis2, P. Porfyridis1, M. Avlianos1, E. Sotiropoulou1, N. Ptohis1, G. Neofitou1; 1Athens/GR, 2Larissa/GR (red-rad@ath.forthnet.gr)

Learning Objectives: 1. To define the principles of Evidence-based Medicine (EBM). 2. To demonstrate how EBM is supposed to change radiological practice in the future.Background: EBM integrates clinical experience and patient values with the best available research information in order to provide sensible answers concerning medical questions in clinical decision making.Procedure Details: The purpose of this exhibit is to help radiographers who have no postgraduate special training in research to use EBM principles and, where appropriate, “technology assessment” principles to find answers that are based on best current evidence concerning problems arising in current practice. Also we intend to demonstrate how EBM can change the way radiographers look after their patients by accessing and applying valid and relevant summaries of guidelines and systematic reviews.Conclusion: EBM can help radiographers in rigorously evaluating all what they are reading and hearing in order to construct a more definitive knowledge basis for every day best medical imaging choices for patient care.

C-885 The extended role of radiographers reporting orbit radiographs for intraocular foreign body in the MRI department of a DGH O. McDonnell, M. Vickers, A. Carson; Craigavon/UK (o_mcdonnell@hotmail.com)

Purpose: Advantages of radiographer reporting of orbit X-rays prior to MRI exami-nation include availability, time saving, reduced cancellations and competence. Two MRI radiographers in our department recently completed a postgraduate diploma in IOFB reporting. The following audit targets have been set: (1) 100% concordance between radiographer and radiologist reports and (2) All cases of ‘not sure’ and ‘IOFB’ are referred to radiologist.Methods and Materials: 100 consecutive orbit X-ray reports were double reported by radiologist and radiographer. The referrer, stated indication, date of report and MRI and incidental findings were also recorded.Results: In 80% of cases, the radiographer acted as a referrer. Indications were appropriate in 100% of cases. In 95% of cases, the radiographer issued the final report with 100% concordance with the reporting radiologist. In 5% of cases, the radiographer referred the examination to a radiologist. Findings included an IOFB in 1 case; metallic foreign body in overlying soft tissues confirmed on lateral view in 2 cases; intraorbital densities identified as artefacts in 2 cases. 95% of orbit X-rays were reported on the day of examination. All examinations were reported prior to MRI examination (mean 2.4 days). In 7 cases, incidental findings of questionable clinical significance were noted by the radiologist. They included frontal sinus aplasia, mucosal thickening within the maxillary antrum and a craniotomy which had been mentioned on the request form.Conclusion: The audit targets have been met efficiently. Radiographer reporting of orbit radiographs for IOFB will continue and its introduction is recommended in all radiology departments.

C-886 A study of adequacy of completion of radiology request forms D. Oswal1, D. Sapherson2, A. Rehman3; 1Leeds/UK, 2Harrogate/UK, 3Huddersfield/UK (diliposwal@hotmail.com)

Purpose: An incompletely filled radiology request form (RRF) is a common problem for radiologists and radiographers alike. The Royal College of Radiologists, London, has issued guidance to all specialities regarding adequate completion for RRFs. This study was designed to quantitatively analyse the adequacy of completion of RRFs at two different district hospitals. This problem has not been quantified in recent literature. We did not analyse the justification of the request.Methods and Materials: 200 forms were randomly selected from each hospital. A score was assigned to each form based on completion of ten different fields. Each field was given a score of 0, 0.5 or 1. Only the completeness of each field was assessed. A blank field was identified as a “miss”. Accuracy and legibility of a completed field were not assessed. Results were compared with available studies in the literature.

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Results: A total of 400 forms were analysed; the mean score was 8.7 (out of 10) per form (range 4.5-10 and median 9). The commonest “misses” (blank fields) were as follows: Doctor’s bleep number: 42%, Patient location: 21%, Questions to be answered: 17%, Doctor’s name: 15%, Date of referral: 11% and Consultant name: 08%.Conclusion: There were significant inadequacies in completing RRFs. This may have medico-legal implications and serious consequences on the quality of overall service provided by the radiology departments. The importance of completion of each field is discussed and suggestions have been made to improve these deficiencies.

C-887 Single-sided reading versus dual-sided reading: Comparison of image quality and radiation dose of two CR systems H.-T. Qi, W. Qin, S. Song, Y. Zhao; Jinan/CN (qihengtao@126.com)

Purpose: To assess and compare the difference in image quality and exposure dose between single-sided reading IP and dual-sided reading IP.Methods and Materials: A contrast-detail phantom CDARD 2.0 was exposed by single-sided and dual-sided reading IP with different mAs sets. The entrance surface doses were recorded for all images. Images were presented to two radiologists on a higher resolution monitor of diagnosis work station. The image quality figure (IQF) was measured for each image. Statistical analysis was performed using Spearman’s correlation test and Wilcoxon signed-rank test to compare the difference in image quality and exposure dose between single-sided and dual-sided reading IP.Results: Using different tube current dosage of 5.6, 12, 20, 25 and 40 mAs, re-spectively, IQF value of single-sided reading IP is 47.95, 37.68, 34.31, 28.61 and 24.65, while that of dual-sided reading IP is 38.83, 29.81, 29.65, 25.16 and 21.43. The difference between the two has statistical significance (p 0.05). Conclusion: Image quality of dual-sided reading IP has been proved to be far superior to single-sided reading IP, in particular for contrast-detail. The image quality of single-sided reading IP is similar to that of dual-sided reading IP only at high dose levels. The clinical application of dual-sided reading IP will reduce the exposure dose to the patient greatly.

C-888 Optimization of anode-filter combinations and tube potentials for digital mammography with matched average glandular dose C. Kohama1, A. Yoshida2, Y. Higashida3; 1Hatsukaichi/JP, 2Mihara/JP, 3Fukuoka/JP (dandelion@do.enjoy.ne.jp)

Purpose: The purpose of this study is to optimize the X-ray image on full-field digital mammography (FFDM) because on digital systems a film density does not depend on radiation dosage and is compensated as suitable image density at even any X-ray exposure.Methods and Materials: Senographe DS (FFDM mammography, GE) were used. We analyzed the relations between target-filter, phantom thickness, or X-ray expo-sure rate and signal detection on the phantom. A 0.7 cm thickness of the CDMAM phantom and a 1 cm, 3 cm, or 5 cm thickness of the PMMA phantom were used. On each thickness of the phantoms, X-ray exposures recommended by Senographe DS (target, filter, and incident X-ray parameters) were performed as a standard radiation exposure and an average radiation dosage of a mammary gland. Changing each thickness of the phantom on the same average X-ray exposure of the mammary gland, and also changing 20-200% (7 levels) of the recommended standard X-ray exposure, C-D diagram (detectability) and digital physical characteristics (S/N, MTF, WS) were analyzed.Results: Although, on the same incident X-ray exposure, there was no significant difference about X-ray image quality on any phantom thickness or any X-ray ex-posure, image quality at any X-ray exposure in each image was visually different on changing incident X-ray parameters.Conclusion: The results indicate that a film density does not depend on radiation dosage and also compensated on digital systems. Further research such as image analysis in consideration of image processing will be needed.

Vascular

CT

C-889 64-slice CT angiography (CTA) of the thoracic aorta using ‘SnapShot Pulse’ prospective electrocardiograph (ECG)-triggered scan: Advantage over conventional high-pitch and ‘Triple Rule Out’ scans J. Horiguchi, C. Fujioka, M. Kiguchi, N. Hirai, N. Matsuura, K. Ito; Hiroshima/JP (horiguch@hiroshima-u.ac.jp)

Learning Objectives: The learning objectives are: 1. To know that scan protocols, ‘SnapShot Pulse’ and ‘Triple Rule Out’ can survey coronary arteries and the aortic valve. 2. To appreciate motion-free images of the aortic valve and coronary artery due to improved temporal resolution. 3. To understand the radiation dose of the three protocols. 4. To learn the further reduction of dose using low voltage.Background: Atherosclerois of the aortic valve and coronary artery often occur simultaneously with aortic disease; therefore it needs one-stop-shop survey. For tracing atherosclerosis, the radiation dose of the test should be “as low as reason-ably achievable (ALARA)”.Procedure Details: Scanning protocol: ‘SnapShot Pulse’ uses several exposures of a 64-row x 0.625 mm-collimation configuration (40 mm) with prospective ECG-triggering axial scan. ‘Triple Rule Out’ uses low-pitch retrospective ECG-gated spiral scan for the scan covering the heart and high-pitch non-ECG-gated spiral scan for the aorta except at the heart level. Conventional scan uses non ECG-gated spiral scan for the entire aorta. The radiation dose of ‘SnapShot Pulse’ is the lowest of the three protocols. Tube voltage of 80 kV and 100 kV: reasonably reduced due to increase in the photoelectric effect and a decrease in compton scattering.Conclusion: 1. Pulsating structures such as the aortic valve may be blurred in high-pitch spiral CT. 2. ‘SnapShot Pulse’ and ‘Triple Rule Out’ scans enable detec-tion of coronary artery stenosis or plaque, as well as aortic valve sclerosis or the bicuspid valve. 3. For repeated examinations, low dose ‘SnapShot Pulse’ scan is most recommended.

C-890 Evaluation of arterial dissection using 64-MDCT: A review of common and uncommon imaging characteristics G.L. Crane, J.N. Tkacz; Boston, MA/US (gabriella.crane@bmc.org)

Learning Objectives: To review the various radiological findings of arterial dis-section using 64-MDCT, including the subtle findings of early dissection which, if undetected, may result in missed or delayed diagnosis. We will review multiple common and uncommon presentations of this entity which we have encountered at our institution.Background: A dissection is a separation of the vessel wall initiated by either a focal tear in the intima at a point of weakness or due to rupture of the vasa vasorum, both followed by subintimal hemorrhage into a region of cystic medial necrosis. This subintimal hematoma can enlarge and propagate through the vessel and can have fatal consequences. Early detection is crucial for management.Imaging Findings: Early signs of dissection include dilatation of the vessel and the presence of an eccentric, crescent-shaped region of high density within the vessel wall representing intramural hematoma. Progression of the dissection results in appearance of a slit-like hypodensity within the vessel, representing the intimal flap which separates true from false lumen. It is important to note the full extent of the dissection and involvement of critical branch vessels.Conclusion: The viewer of this exhibit will gain a deeper understanding of the pathophysiology of arterial dissection and the various presentations and pitfalls which can be seen at different stages of disease.

C-891 MDCT angiography in the preoperative planning of DIEP and SIEA flap breast reconstruction J. Pamies Guilabert, P. Braun, V. Ballester Leiva, F. Gomez Muñoz; Valencia/ES (pamies_jos@gva.es)

Learning Objectives: Show the utility of MDCT angiography in the identification of the perforant vessels used as vascular pedicles in DIEP flap in breast recon-struction. Additionally, explain the marking procedure of the perforant vessels for location and surgical dissection.Background: Flaps of the deep inferior and superficial epigastric vessels (DIEP and SIEA) are recently used as autogenous tissue in breast reconstruction of mastectomised patients, obtaining high quality of reconstruction with low morbility. The high spatial resolution of MDCT is very useful in the evaluation of abdominal

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vascular anatomy, being able to identify the position, size, course and morphology of the musculocutaneous perforant vessels.Procedure Details: From February 2006 till August 2007 we performed 24 MDCT angiography studies (Toshiba Aquilion 64). MIP and 3D VR images were obtained to identify the perforators and to determine its medial or lateral course to the rectus abdominis muscle, size, length and distance to skin and to mark superficially each perforator in a coordinate system, using the navel and the iliac spines as refer-ence. The superficial inferior epigastric veins, its location, course and size, due to its importance in the drainage of the flap and the superficial inferior epigastric arteries, if present, were also identified.Conclusion: MDCT is a highly effective tool in the preoperative study of abdominal perforator flaps, providing a noninvasive global approach of the vascular anatomy and the abdominal wall, allowing the preoperative selection of an adequate perfora-tor for surgical dissection.

C-892 The spectrum of cardiovascular lesions in multitrauma patients G. Laguillo, A.M. Quiles, A. Gelabert, M. Boada, N. Cañete, M. Febrer; Girona/ES

Learning Objectives: To illustrate different cardiovascular lesions in a large series of multitrauma patients. To appreciate the value of 2D and 3D MDCT postprocessing techniques in their diagnosis. To describe potential complications and review the therapeutic approach of these lesions.Background: The whole-body CT scan is essential to perform a fast and accurate diagnosis of traumatic lesions. Cardiovascular lesions remain amongst the most challenging of all injuries seen in the field of trauma, frequently associated with important life-threatening complications.Imaging Findings: A large number of cardiovascular lesions have been diagnosed in our department, such as aortic rupture, carotid lesions (pseudo-aneurysm and carotid dissection), lesions of abdominal vessels and peripheral vascular lesions, as well as right atrium rupture. We reviewed imaging findings using MIP, MPR and 3D reconstructions. Postprocessing techniques are useful to decide the therapeutic approach of these lesions that can be endovascular, surgical or conservative.Conclusion: An early detection of cardiovascular lesions is critical, as survival is improved by its emergent treatment. Therefore, during the assessment of whole-body CT scan in traumatic patients, a careful evaluation of the heart and vascular structures should be done to avoid overlooking these kinds of lesions.

C-893 Multi-detector-row CT angiography in the study of inferior vena cava malformations L. Saba1, C. Urigo2, M. Conti2, G. Mallarini1; 1Cagliari/IT, 2Sassari/IT (lucasaba@tiscali.it)

Learning Objectives: The learning objectives in this work are: 1) to understand the embryology and anatomy of inferior vena cava (IVC); 2) to review the current indications for performing multidetector row CT in the diagnosis of IVC anomalies, underlining radiation exposure and diagnostic efficacy; 3) to review the most important MDCT post-processing techniques as maximum intensity projection (MIP), multiplanar reconstruction (MPR), volume rendering (VR) and curved planar reconstruction (CPR) in the study of IVC; 4) to learn the benefits and pitfalls of each technique in the study of IVC.Background: IVC malformations may be congenital or acquired. The IVC devel-ops from four segments during the sixth through eight weeks after conception, including a hepatic portion derived from the proximal right vitelline vein, a prerenal segment arising from the right subcardinal vein, a renal segment derived from the subcardinal-supracardinal anastomoses, and an infrarenal portion arising from the right supracardinal vein. Developmental abnormality of each segment produces specific anomalies. IVC malformation can determine several condition as pelvic varices and abdominal pain.Imaging Findings: In this work, we show the MDCT imaging findings, including congenital and acquired IVC absence, with demonstration of the development of the collateral arcades for each type of anomaly.Conclusion: MDCT angiography can identify with excellent anatomical definition the absence of IVC and its collateral vicariate system. The use of MIP and VR show optimal potentiality in the study of IVC pathology.

C-894 3D multi-detector CT evaluation of acute thoracic aortic syndromes: What the radiologist needs to know J.M. Moriarty, D.T. Murphy, L.P. Lawler; Dublin/IE (jonnymoriarty@yahoo.com)

Learning Objectives: The objectives of this exhibit are to present a pictorial essay of the 3D MDCT features of acute thoracic aortic emergencies, and describe both the established treatment protocols widely in use and also the new innovations in endovascular management of these life-threatening conditions.Background: Acute aortic syndromes are severe, potentially rapidly fatal disorders of thoracic aorta that span a spectrum of disease from acute aortic dissection, penetrating ulcer, intramural haematoma to post-traumatic aortic transections and pseudo-aneurysm formation. In recent years, MDCT has allowed the rapid and non-invasive evaluation of these conditions, all but eliminating conventional angiography as a diagnostic tool. At the same time, endovascular therapeutic approaches have begun to overtake open repair as first line treatment.Imaging Findings: This exhibit presents a review of the optimal imaging pa-rameters and diagnostic features of the various acute aortic syndromes on 3D MDCT angiography. Correlation is made with traditional angiographic findings and particular attention is placed on the evolving role of endovascular stenting in the management of these conditions.Conclusion: Rapid, non-invasive, sensitive evaluation of acute aortic syndromes with 3D MDCT is a vital tool for the radiologist in not only the timely diagnosis of these potentially fatal conditions, but also in the careful planning of therapeutic intervention.

C-895 Acute aortic pathologies: A spectrum of diseases depicted on 64-slice multi-detector row CT M. Bertolotto, R. Pizzolato, M. Belgrano, M. Ceschin, M. Doddi, M. Cova; Trieste/IT (bertolot@univ.trieste.it)

Learning Objectives: To focus on pathophysiology and clinical presentation of a spectrum of acute aortic diseases. To illustrate the examination technique and imaging features of pathologies presenting as aortic emergencies on 64-slice multi-detector row CT.Background: Acute aortic pathologies refer to a spectrum of emergencies that include aneurysm leak and rupture, dissection, intramural hematoma, penetrating ul-ceration, acute aortoiliac thromboembolic obstruction, and traumatic transection.Procedure Details: Key factors for a successful CT angiography include a combination of the best scanning profile with the precise delivery of the contrast medium, as well as high-quality imaging display by means of multiplanar and 3D reformations. Scans are obtained during the arterial phase at breath hold using a care bolus technique with automatic threshold. High injection rates of high-concentration iodinated contrast media are preferred, followed by a saline flush. Cardiac triggering can be useful to reduce artefacts produced by vessel pulsation and improve visualization of intimomedial flaps. An excellent evaluation of acute aortic pathologies is obtained. In particular, when 64-slice multi-detector row CT is used, multiplanar reformations obtained from isotropic submillimetric data sets of slices allow an excellent evaluation of wall leaks and hematomas, complex in-timomedial flaps, extent of thrombosis, and extraluminal changes. Full evaluation of postoperative anatomy and complications is obtained. Multiphasic imaging may be required to evaluate associated parenchymal pathologies.Conclusion: Patients presenting with acute aortic pathologies often have a similar clinical profile. Multi-detector row CT plays a key role in assessing these patients.

C-896 Active gastrointestinal bleeding: Spectrum of CT angiography findings and pitfalls S. An, W. Lee, J. Chung, J. Park; Seoul/KR (sangbu@radiol.snu.ac.kr)

Learning Objectives: To illustrate the spectrum of CT angiographic findings of ac-tive gastrointestinal (GI) bleeding. To describe the pitfalls in computed tomography (CT) interpretation of active GI bleeding.Background: CT angiography is rapid, noninvasive, and accurate in detecting and localizing sites of bleeding in patients with active GI bleeding. Between June 2005 and May 2007, 265 patients were evaluated with CT angiography for the detection of active GI bleeding. Among them, 50 patients had CT findings of active GI bleeding and 31 patients were confirmed by conventional angiography. In this exhibit, we will illustrate various imaging findings of active GI bleeding according to the sites involved. The pitfalls during the interpretation will be also described and illustrated.

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Imaging Findings: The stomach was the most common origin of bleeding (n=19). Other sites were small bowel (n=13), duodenum (n=6), colon (n=4), rectum (n=3), esophagus (n=2), hepatic artery (n=1), superior mesenteric artery (n=1), and within biliary stent (n=1). Major imaging findings of active GI bleeding were jetting or stagnation of contrast media within the lumen on early arterial phase. But delayed phase was more useful (n=6) especially in the detection of duodenal and small bowel bleeding. Surgical materials and tablets can obscure correct diagnosis. Prominent vascularity without bleeding is another cause of misdiagnosis.Conclusion: Active GI bleeding could be well identified on delayed phase as well as on arterial phase in some cases. Knowledge of pitfalls such as artifacts and pseudolesions is important for the interpretation of CT angiography in the GI bleeding survey.

C-897 64-row MDCT angiography of the abdominal vessels: Protocols, post-processing and clinical implications C.N. De Cecco, P. Paolantonio, F. Iafrate, F. Vecchietti, P. Lucchesi, A. Laghi; Rome/IT (carlodececco@gmail.com)

Learning Objectives: To evaluate state-of-the-art imaging of abdominal vessels with 64-row MDCT angiography. To analyze protocols, injection strategies and post-processing techniques. To report the clinical advantages.Background: A 64-row MDCT offers the possibility of obtaining a perfect depic-tion of all abdominal vessels and also of small accessory branches. It represents an invaluable tool for both interventional and surgical procedures. Moreover, the knowledge of life-threatening conditions, such as rare vascular anomalies, could lead to better clinical management.Imaging Findings: We present vascular abdominal images of normal, aberrant and pathological abdominal arterial vascularization obtained with a 64-row CT. We also analyze the actual protocols, focusing our attention on post-processing techniques.Conclusion: In the evaluation of abdominal vessels, 64-row MDCT angiography adds important information. It also plays an important role in presurgical planning of challenge interventions. Post-processing techniques represent a fundamental tool in the analysis of complicated vascular conditions.

C-898 Cardiac arrest: Helical CT findings M. Scialpi1, L. Volterrani2, M.A. Mazzei2, F. Mazzei2, R. Grassi3, A. Rotondo3, L. Lupattelli1; 1Perugia/IT, 2Siena/IT, 3Naples/IT (michelescialpi@libero.it)

Learning Objectives: To describe the thoracic and abdominal imaging features of cardiac arrest that may occur during helical CT examination.Background: Cardiac arrest is a rare, but critical event, that may occur during helical CT examination. In the last 6 years, in our institution, 12 cardiac arrests oc-curred during an emergency CT examination. Helical CT was performed for blunt trauma (n = 8), spontaneous rupture of thoracic aneurysm (n = 1) and of abdominal aortic aneurysm (n = 3).Imaging Findings: CT findings related to the stasis or reflux of the contrast mate-rial in the heart, in the thoracic and abdominal vessels and in the abdominal solid organs were retrospectively analyzed.Helical CT findings were as follows: reflux of contrast into the coronary sinus (n = 1), no opacification of the left ventricle (n = 8), lack of cardiac motion artifact (n = 11), retrograde flow of contrast agent via the inferior vena cava (IVC) with opacification of renal veins (n = 9), hepatic vein (n = 12), IVC (n = 10), portal vein (n = 2), renal parenchyma (n = 2) and hepatic parenchyma (n = 8).Conclusion: Because cardiac and blood pressure monitoring is not routinely ap-plied during CT study, recognition of the manifestations of CT and understanding of the underlying mechanisms of sudden cardiac arrest are important in the prompt management of this rare but critical event.

C-899 What every radiologist should know about multi-detector row CT angiographic imaging of peripheral arterial bypass complications M. Santoro, R. Iezzi, D. Giancristofaro, V. Pasqua, A.R. Cotroneo, M.L. Storto; Chieti/IT (r.iezzi@rad.unich.it)

Learning Objectives: 1. To illustrate the main types of bypass graft used to revascularize peripheral arteries. 2. To describe the optimal CT technique for the evaluation of peripheral arterial bypass. 3. To describe radiological findings of bypass complications on axial and reconstructed images.Background: It has been proved that CT is a powerful tool in evaluating lower extremity bypass grafts and their related complications. Grafts can be autologous,

being made up of saphenous veins, or synthetic, and can be classified into inflow and outflow types. Inflow grafts supply blood to the common femoral artery, by-passing the distal aorta and iliac arterial disease. These grafts may start from the axillary artery, so understanding the type of graft is essential before defining the region that has to be scanned. Outflow grafts carry blood from the femoral artery level to the popliteal, tibial, or pedal arteries and are usually placed to treat distal artery disease. The morbidity associated with surgical bypass may be due to early complications (related to technical procedure and poor run-off), late complications (intimal proliferation, atherosclerosis), and graft infection.Procedure Details: This exhibit reviews the MDCTA technique for obtaining optimal images to evaluate the bypass of peripheral arteries, the role of reconstructed images in the assessment of the graft, and the complications leading to failure of the graft (stenosis, thrombosis, intimal iperplasia, anastomotic stenosis or pseu-doaneurysms, infection).Conclusion: MDCTA is a reliable tool in providing anatomic information on the bypass of peripheral arteries; it is also effective in the detection of early and late complications.

C-900 Multi-detector row CT angiographic imaging in the follow-up of patients who underwent endovascular abdominal aortic aneurysm repair: A pictorial review D. Giancristofaro, R. Iezzi, M. Santoro, D. Gabrielli, A.R. Cotroneo, M.L. Storto; Chieti/IT (r.iezzi@rad.unich.it)

Learning Objectives: To learn the CT scanning technique to acquire the data for the follow-up of patients who underwent endovascular abdominal aortic aneurysm repair (EVAR); to describe the normal aspect of different stent-graft on axial and reconstructed three-dimensional images; to illustrate the aspect of EVAR-correlated complications on axial and reconstructed three-dimensional images.Background: EVAR is an accepted alternative to open surgery. The success of EVAR depends on strict follow-up for the early detection and treatment of compli-cations. Multidetector CT-angiography (CTA) is fast, safe, and minimally invasive and, therefore, represents the standard of reference in the follow-up of patients who underwent EVAR. The purpose of this exhibit is to review the normal aspect of different aortic stent-grafts as well as EVAR-correlated complications detected on axial and reconstructed 3D images.Imaging Findings: At CTA, different aortic stent grafts may be accurately depicted in all their components. Unenhanced, arterial and delayed contrast-enhanced CTA allow early detection of complications correlated with EVAR such as endoleaks, graft migration, graft occlusion and graft infections.Conclusion: CTA is a reliable diagnostic tool for detection of EVAR complications. A careful patient follow-up is essential for the long-term success of the procedure.

C-901 The accuracy of sixty-four detector row helical CT on the diagnosis of pulmonary embolism: Prospective evaluation of 112 emergency department patients and inpatients in a patient outcome study C. Calisir, U.S. Yavas, I.R. Ozkan; Eskisehir/TR (cuneytcalisir_72@yahoo.com)

Purpose: To prospectively evaluate the accuracy of multidetector-row computed tomography (MDCT) in the emergency setting for the diagnosis of pulmonary embolism (PE).Methods and Materials: 112 consecutive patients with clinically suspected PE, according to revised Geneva score, were assessed. CT scanning was performed with a MDCT scanner. CT venography (CTV) was also performed. CT studies were interpreted first in the emergency setting by residents and subsequently by consensus consisting of a resident, a general radiologist, and a chest radiologist. Untreated patients with normal results were contacted by telephone after three months. To determine the accuracy of MDCT in a three-month follow-up patient outcome study, 39 patients were excluded from the study.Results: The concordance between the two reading sessions for CT angiography (CTA) results was good. The proportion of nondiagnostic CT acquisitions was 11.6% according to second interpretation. Images of 31 CTA examinations revealed PE. Deep venous thrombosis (DVT) was detected in 80.6% of the patients with posi-tive results at CTA. None of 112 patients with negative results at CTA had DVT at CTV. The three-month rate of thromboembolic events after negative results was 0%. The sensitivity of MDCT was 100%, specifity was 83.3%, and the accuracy was 90.4%.Conclusion: MDCT enables diagnosis in 88.4% of cases and offers a high sensi-tivity, but relatively low specifity in residents. Radiologists should be more careful not to misdiagnose motion artifact as PE. False positive results can be prevented by determining motion artifacts with the use of lung images.

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C-902 Aortic enhancement at CT angiography: A contrast injection protocol based on patient lean body weight Y. Yanaga, K. Awai, T. Nakaura, T. Namimoto, Y. Yamashita; Kumamoto/JP

Purpose: To compare inter-patient variability of aortic enhancement (AE) between CT angiography (CTA) injection protocols dose-adjusted for lean body weight (LBW) and total body weight (TBW).Methods and Materials: CTA for the whole aorta with a 64-detector CT (Bril-liance-64, Philips) was performed in 72 patients (mean age, 67.6 years) with confirmed or suspected aortoiliac diseases. Bolus tracking was used to time the start of scanning; the trigger threshold level was set at 150 HU. In protocol 1 (P1), 37 patients received contrast medium at 450 mg iodine (I) per kg LBW. The others (P2) received 360 mgI per kg TBW. We intended the dose for a 60-kg patient with 12 kg of fat tissue in P1 to be the same as that used in P2. We compared the two protocols for mean AE + the standard deviation (SD).Results: AE in P1 and P2 was 311.5 and 318.1 HU, respectively; there was no statistically significant difference between the 2 protocols (t-test, P=0.58). SD of AE in P1 and P2 was 40.0 and 59.8 HU, respectively; SD for P1 was significantly smaller than for P2 (Levene test, P 0.01).Conclusion: Contrast-injection protocols for CTA with the dose tailored to LBW may lessen inter-patient variability of AE compared to protocols whose dose is adjusted for TBW.

C-903 Initial evaluation of fast switching dual energy scanning in head CT angiography using 40 mm coverage volume CT K. Sugisawa, Y. Okano, M. Jinzaki, S. Kuribayashi, N. Monden, Y. Imai; Tokyo/JP

Purpose: The purpose of this study was to evaluate separation between contrast enhanced arteries and bone around ICA and COW with the dual energy CT imaging in head CT Angiography (CTA), and optimize its contrast material injection method.Methods and Materials: Thirty patients with age ranged from 23 to 79 years (average: 57) underwent head CTA with 90 ml contrast material (300 mgI/ml) by the fast switching dual energy scanning (80 and 140 kVp) on the 64-slice volume CT, and they were randomly separated by 3-group. In group-I, the contrast material was injected by 4.0 ml/sec with constant flow, in group-II, was 4.0 to 2.0 ml/sec with decelerating flow, and in group-III, was 5.0 to 2.5 ml/sec with decelerating flow. We reconstructed dual energy iodine enhanced images and evaluated its visibility of arteries by radiology physicians. And also, CT number of arteries at COW (posi-tion-A) and distal side (B) were measured on 80 kVp images.Results: In artery visibility, 6/10 in group-I, 5/10 in group-II, and 8/10 in group-III were acceptable. In group-I, average CT number of A was 362 HU and B was 143 HU. In group-II, A was 330 HU and B was 191 HU. In group-III, A was 500 HU and B was 253 HU. No significant differences between groups-I and II (p 0.05). Group-III improved for both A and B positions (p=0.039, 0.0095) and had good correlation between artery visibility and CT number (R2=0.9058).Conclusion: Dual energy method clearly demonstrated arteries abound ICA and COW. This provided better diagnosis of aneurysm without time-consumed post-processing in head CTA.

C-904 64-slice spiral carotid CT angiography using CareDose4D: Effects of current and pitch factor on image quality W. Liu, H.D. Xue, Z.Y. Jin; Beijing/CN (lw.pumch@hotmail.com)

Purpose: To assess the necessity of dose (reference mAs (refmAs)) and pitch factor adjustment at 64-slice spiral carotid CTA when CareDose4D is applied.Methods and Materials: A total of 60 subjects divided randomly into two groups (each 30) were examined by 64-slice spiral CT. Group A underwent scanning protocol with a refmAs=230 and pitch factor=1.4. For group B, refmAs=205 with pitch factor=1.0 was applied. Both groups were scanned with CareDose4D acti-vated. Effective current (effmAs) of shoulder and neck were recorded. Noise was assessed by measuring standard deviation (SD) CT value in muscle. Body mass index (BMI), scanning time, venous enhancement and radiation dose were also evaluated for each data set.Results: Noise at shoulder region was found higher in group A than that in group B [13.3Hu vs. 11.1Hu, P 0.01]. The effmAs at shoulder region was lower in group A than that in group B [(142 17) vs. (166 21), P 0.01]. However, no significant difference of noise was seen at neck [6.2Hu vs. 6.7Hu, P 0.05], though the effmAs was higher in group A [(76 7) vs. (67 5), P 0.01]. The scan time was significantly shorter in group A [4.9s vs. 6.7s, P 0.01]. Venous enhancement did not prevent confident assessment of arterial diseases in both groups. No significant difference of radiation dose in both groups [(7.33 0.34)mGy vs. (7.55 0.68)mGy, P 0.05].

Conclusion: When CareDose4D is activated, image quality acquired using a refmAs=205 and pitch factor=1.0 was superior to that obtained using refmAs=205 and pitch factor=1.0 at shoulder region, which is due to higher effmAs achieved.

C-905 Takayasu arteritis: Luminal and mural evaluations of carotid artery with CT angiography W. Liu, Z.Y. Jin, H.D. Xue, H. Sun, X. Wang; Beijing/CN (lw.pumch@hotmail.com)

Purpose: To retrospectively review carotid CT angiography (CTA) of patients with Takayasu arteritis (TA) so as to evaluate carotid luminal and mural changes in TA, and to compare mural changes between patients with and without disease activity.Methods and Materials: CTA images were retrospectively reviewed in 50 patients with confirmed TA affecting carotid arteries. Images included two distinct phases: pre-contrast transverse images and arterial-phase images combining with the ap-plication of 3D processing. Vessel wall thickness was measured on arterial-phase images. We correlated wall thickness with the presence of activity as assessed by the national institutes of health (NIH) criteria.Results: Contrast enhanced CT scanning combining with the application of 3D processing could clearly show carotid vascular luminal abnormalities, such as narrowing (58%), obstruction (21%), dilatation (4%), and collateral branches. Meanwhile, 16% (8/50) of patients showed normal luminal diameter of bilateral carotid arteries in spite of mural changes. 20% (10/50) patients with vessels above carotid bifurcation were affected. Wall thickness increased in 100% of the patients. Precontrast transverse images revealed a high-attenuation carotid wall in 32 of 32 patients with active disease and 15 of 18 patients without active disease (p 0.05). In patients with active disease, the wall thickness was more than those without active disease [(0.40 0.12) cm vs. (0.23 0.14) cm, p 0.05].Conclusion: CT angiography revealed carotid luminal abnormalities as well as mural changes in patients with TA. Arterial wall thickness increased in TA patients, especially in active disease.

C-906 The role of multidetector CT angiography in decision making in severe carotid stenosis A. Ben Ely, A. Puzhevsky, A. Bass; Rishon Le Zion/IL (liogonky@yahoo.com)

Purpose: The purpose of the present study is to compare the concordance rates of Multidetector CT Angiography (MCTA) with Duplex ultrasound (DUS) in clinical routine practice and to assess the value of Multidetector CT Angiography (MCTA) in altering severe carotid stenosis surgical decisions.Methods and Materials: Twenty-eight symptomatic patients (post TIA or stroke) were admitted for MCTA for verification of DUS results showing moderate (50-69%) or severe (70-99%) carotid stenosis, or suspected occlusion (unilateral or bilateral). In processing the Doppler data, we used the recent recommendations of the Radiologist Consensus Conference (2003). Fifty-six cases were evaluated by MCTA. The assessment of degree of stenosis was based on NASCET criteria.Results: In 22 ICAs with severe stenosis according to DUS, only 9 were confirmed by MCTA. In 13 other cases, the degree of stenosis on MCTA was estimated as moderate, equaling a disagreement in more than 50% of cases. Overall, MCTA revealed 10 cases of severe stenosis, 9 of which were also severely stenotic on DUS, with only one exception, where moderate stenosis on DUS later proved by angiography, was graded as severe on MCTA.Conclusion: According to our results, based on a limited group of patients, we suggest that DUS tends to overestimate the degree of stenosis. MCTA enabled avoiding intervention in 54% of cases with a discrepancy. Hence DUS cannot be used as the sole preoperative imaging modality, and MCTA appears to be highly recommended in all situations of severe ICA stenosis.

C-907 Virtual angioscopy of arterial disease revisited S.K.V. Bommana1, U.D. Patil1, R.M.S.V. Vadapalli2, B.Y.T. Arya1, R.H.N. Hanasoge1; 1Bangalore/IN, 2Colombo/LK (bommanasubhash@yahoo.com)

Purpose: 1. To discuss the usefulness of virtual arterial navigation by CT angiog-raphy in various arterial diseases. 2. To highlight the imaging appearances of these arterial diseases in virtual angioscopy.Methods and Materials: Patients referred for CT angiography for arterial diseases are selected retrospectively and virtual angioscopic study of the arteries was done. This poster discusses the characteristic appearances of the various arterial diseases in virtual angioscopy.

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Results: Virtual angioscopy is a very useful technique in the evaluation of the arterial diseases and acts as an adjuvant to the image evaluation. It gives more surgeon friendly images and helps in the treatment.Conclusion: Virtual angioscopy is a novel innovative imaging technique of evalua-tion of arterial diseases. This poster discusses the characteristics imaging appear-ances of the arterial diseases in virtual angioscopy and highlights its importance as an adjuvant in the image evaluation.

Vascular

DSA

C-908 Lower limb venography: The forgotten ‘gold standard’ A. Saini, N. Fotiadis, R. Dourado, F.S. Ahmad, I. Ahmed, T. Sabharwal, A. Adam; London/UK (ashsaini@doctors.org.uk)

Learning Objectives: Over the last10 years, dulpex ultrasound has become the primary modality used to assess lower limb venous disease. As a result, the use of contrast venography has declined and in some institutions is rarely performed. This pictorial review is based on the authors’ experience and aims to review the indications, techniques, venous anatomy and pathology as demonstrated by lower limb contrast venography.Background: Contrast venography has long been considered the ‘gold standard’ in the assessment of lower limb veno-occlusive disease and can effectively dem-onstrate thrombus within the below-knee veins. Since duplex ultrasound has the advantages of being non-invasive and does not use ionising radiation, it is favoured by both clinicians and patients as the initial diagnostic test for deep vein thrombosis. Radiologists in training no longer have the exposure previously available and may not be familiar with the techniques or the appearances of common pathology.Procedure Details: The indications, technique and radiological appearances of lower limb venography are illustrated. Emphasis is placed on common anatomical variants that are often poorly recognised by routine duplex ultrasound. The use of venography in the assessment of venous malformations, venous tumour encase-ment and in the post-phlebitic limb are also discussed.Conclusion: Venography remains the ‘gold standard’ in the assessment of lower limb venous disease. However since this method is no longer in frequent use, it is imperative that radiologists remain familiar with the current indications, technique and interpretation of the test.

C-909 Usefulness of 3-dimensional rotational angiography with flat detector in the management of transplanted kidney: Preliminary experience A. Ianniello, G. Carrafiello, D. Laganà, D. Santoro, F. Fontana, C. Fugazzola; Varese/IT (ianand@libero.it)

Purpose: To evaluate the usefulness of 3D rotational angiography (3D-RA) in the management of transplanted kidney.Methods and Materials: 3D-RA was consecutively performed in 18 renal trans-planted patients: 8 with suspicion of renal artery stenosis and 10 with suspicion of ureteral fistula. A series of images were acquired while the C-arm (Allura Xper FD20- Philips) of the equipment rotated around the region of interest. Contrast media in different concentrations (flow rate:3-4 ml/sec, duration time:10 sec) were injected through a 5 F catheter, with crossover technique, in ipsilateral iliac artery for the study of renal artery and 10-20 ml were gently injected through a 18 G needle for the study of urinary tract.Results: Three stenoses of renal artery were found and also 8 ureteral fistulas were demonstrated. The 3D reconstructions gave a better description of the renal artery stenoses with only 30-40 ml of contrast media and permitted to choose the correct orientation of C-arm to perform the angioplasty. Also, a correct visualization of fistulas gate was demonstrated in all cases, treated with double pig tail stents and nephrostomy catheters positioning.Conclusion: 3D-RA of the transplanted kidney provides to reduce contrast media administration, radiation dose and operative time in the management both of renal artery stenosis and ureteral fistulas.

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C-910 Hemangiomas and vascular malformations: A practical approach based on MR findings M.E. Nazar, A. Nápoli, D. Sarroca, C. Morales, H. Di Nunzio, C.H. Bruno; Buenos Aires/AR (menazar@arnet.com.ar)

Learning Objectives: To evaluate the usefulness of MRI dynamic sequences and of MRA with gadolinium in patients with diagnosis or clinical suspicion of hemangiomas and vascular malformations. To describe its characteristic findings, and to establish the keys to perform a suitable classification and a correct differential diagnosis.Background: Vascular anomalies are one of the most difficult lesions to diagnose and treat. Clinical manifestations vary from asymptomatic patients to congestive cardiac failure. Several classifications have been proposed. History and physical examination results can readily be used to diagnose the majority of them. However, imagenologic assessment is often required in certain circumstances. Based on our experience with 51 patients from August 2005 to July 2007, we will describe the characteristic MR findings of these malformations.Imaging Findings: The vascular anomalies found were: 14 hemangiomas, 11 arteriovenous malformations, 10 venous malformations, 8 lymphangiomas, 6 cases of Von-Klippel Trenaunay syndrome, 1 Kasabach-Merrit syndrome and 1 Rendu-Osler syndrome.Conclusion: Conventional and dynamic contrast-enhanced MR parameters can be used in combination to categorise vascular malformation and hemangiomas and to allow not only identifying malformation extension and morphology, but also differentiating between high- and low-flow vascular anomalies.

C-911 Acute aortic dissection: Typical and atypical MRI findings A. Buzzi, S. Ballester, C. Dominguez, R.J. de Cabo, F. Arredondo, L. Santamarina; Buenos Aires/AR (aebuzzi@fibertel.com.ar)

Learning Objectives: 1.To describe the pathological and clinical characteristics of acute aortic dissection (AAD) and the diagnostic information needed to proper treatment. 2. To illustrate the typical and atypical MRI findings.Background: AAD is the most common emergency affecting the aorta. It is a life-threatening condition, and untreated it can rapidly be fatal. Advances in surgi-cal and medical treatment have markedly improved survival. Its prompt diagnosis remains essential for successful management. However, atypical imaging features and diagnostic pitfalls can delay lifesaving therapy.Imaging Findings: MRI can produce high-quality images in the transverse, coronal, sagittal, and oblique planes of the aorta, and provide the information needed for a correct treatment: a) confirm or exclude the diagnosis of dissection, b) determine whether the dissection involves the ascending aorta (type A) or is confined to the descending aorta (type B), and c) a number of anatomical features (extent, sites of entry and reentry, presence of thrombus in the false lumen, extent of branch vessel involvement, presence and severity of aortic insufficiency, presence or absence of a pericardial effusion). T1 SE techniques offer excellent anatomic images with high contrast between the intimal flap and the low signal intensity of rapidly flowing blood. GRE and phase-contrast MRI also provide functional information.Conclusion: Noninvasive imaging allows prompt and reliable diagnosis of AAD and has largely supplanted aortography. MRI is an excellent modality for evaluation of patients with suspected dissection. It can image the aorta in multiple planes and give functional data on flow.

C-912 High-resolution MRI of the cervical arterial wall C. Oppenheim, O. Naggara, E. Touzé, J.-F. Toussaint, J.-L. Mas, J.-F. Méder; Paris/FR (c.oppenheim@ch-sainte-anne.fr)

Learning Objectives: 1. To present a comprehensive guide to perform high-reso-lution MRI (HR-MRI) of the cervical arteries. 2. To provide an overview of the MR patterns of cervical arterial wall diseases, including dissections and atherosclerosis. 3. To explain the method of differentiation of stable from unstable atherosclerotic plaques on HR-MRI for prognostic purposes.Background: HR-MRI is increasingly used for the identification of major compo-nents of atherosclerotic plaque i.e. the lipid core, mural haemorrhage, calcifica-tions as well as the fibrous cap. Beyond atherosclerosis, HR-MRI may be used for diagnostic purposes: confirmation of cervical dissection, etiological diagnosis in case of arterial occlusion, etc.

Procedure Details: This exhibit explains the choice of phased array surface coils and sequences parameters. It provides tips for optimal image quality and discusses current limitations. It highlights the fact that vertebral and carotid arteries can both be imaged with HR-MRI. Typical HR-MR findings in atherosclerotic plaques, arterial dissection, and other rare causes of stroke are illustrated. The imaging pattern of unstable/stable atherosclerotic plaques are explained.Conclusion: High-resolution MRI of the cervical arterial wall can provide information that is useful in practice for the purpose of diagnosis and prognosis.

C-913 Pre-operative assessment of potential, live renal donors: Venous variations as found on contrast-enhanced magnetic resonance angiography J.B. Straiton, G.H. Roditi; Glasgow/UK (jack_straiton@yahoo.co.uk)

Learning Objectives: (1) Understand the role of contrast-enhanced MRA (CE-MRA) in the evaluation of renal venous vasculature in potential, live renal donors. (2) Recognise CE-MRA appearances of anomalous/unusual renal venous drainage. (3) Understand the venous configurations that may preclude donor nephrectomy. (4) Appreciate how blood pool contrast agent (BPCA) CE-MRA improves venous visualisation.Background: CE-MRA is an established technique for the prospective evalua-tion of renal vasculature in potential, live donors. Previous studies have primarily focused on delineating anomalous arterial anatomy and their variations that may preclude donor nephrectomy. Laparoscopic donor nephrectomy aims to reduce donor morbidity. However, procedures may require conversion to open nephrectomy based on complex venous anatomy not prospectively identified. Hence, although renal venous anatomy is thought to be more consistent than arterial, the accurate pre-operative characterization of venous anomalies is essential.Imaging Findings: From a series of 119 CE-MRAs performed in our department between 1 September 2003 and 31 August 2007, all examples of venous variation were reviewed. The exhibit includes examples of retroaortic and circumaortic left renal veins, variations in left lumbar and gonadal connections and multiple right renal veins. The use of BPCA CE-MRA techniques, improving spatial resolution and venous conspicuity, are discussed and explained.Conclusion: Recognition of the various renal venous configuration appearances as demonstrated with CE-MRA is important for pre-operative planning of living renal donors.

C-914 Non-enhanced MR angiography of the pelvic vessels T. Koyama1, T. Okada1, K. Fujimoto1, N. Satogami1, A. Nakai1, A. Ninomiya2, S. Sato2, K. Togashi1; 1Kyoto/JP, 2Tokyo/JP (montpeti@kuhp.kyoto-u.ac.jp)

Learning Objectives: To introduce emerging techniques in non-enhanced MR angiography of the pelvic region, illustrating the techniques and sequence param-eters to optimize the images.Background:MR angiography (MRA) of pelvic vessels is not only applicable to various vascular disorders, but is also useful for surgical planning. MRA of pelvic vessels has been performed by 2D time of flight (TOF) or contrast-enhanced 3D-MRA with fluoroscopic trigger technique. However, these techniques have limitations in spatial resolution and necessitate long scanning time. Time-spatial labeling inversion pulse (Time-SLIP) is an emerging technique of arterial spin label-ing and permits detailed angiography of both arteries and veins. The purpose of this exhibition is to introduce non-enhanced MRA utilizing Time-SLIP of the pelvic vessels technique, illustrating sequences optimization. The clinical application of this technique is also discussed.Procedure Details:Non-enhanced MRA with Time-SLIP can be basically performed employing parallel imaging, combined with either 3D balanced steady-state free-precession (SSFP) technique or fast advanced spin-echo (FASE) technique, which utilizes 3D half-Fourier spin-echo sequence with ECG-triggering. In both techniques, the longer inversion time results in increased signal, but less contrast between arteries and veins. In FASE technique, depiction of fast-flow vessels are obtained during the diastolic cardiac phase, and adjustment of timing of the triggering can regulate the depiction of the arteries. In SSFP, increased number of segmentation provides better image, though scanning time becomes longer.Conclusion:Non-enhanced MRA with Time-SLIP is a promising technique for obtaining detailed angiography of the pelvic vessels. The sequence parameters should be adjusted according to the clinical application.

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C-915 Assessment of dysfunctional hemodialysis access fistula and graft of the upper extremity with high resolution contrast enhanced MR angiography A.A.A. Abdel Razek, A. Eltantawey, E. Saad; Mansoura/EG (arazek@mans.eun.eg)

Purpose: To assess dysfunctional hemodialysis access fistula and graft of the upper extremity with high-resolution three dimensional contrast enhanced MR angiography.Methods and Materials: Three-dimensional contrast enhanced MR angiography (CE-MRA) was performed for 33 patients (12 M, 11 F mean age 34 ys) with dys-functional hemodialysis access fistula or graft of the upper extremity. This study was conducted on 1.5 tesla MR unit (Symphony-Siemens). The parameters used were: TR=7 msec, TE=3 msec, Flip angle=40 degree, FOV=25-35 cm and matrix =256 x 256. Bolus of gadolinium-DTPA was injected in the forearm (0.2 mmol/kg at the rate of 3 ml/sec followed by 20 ml saline flush at the same rate). Multiple series are taken after contrast administration. The first acquisition served as a mask, which was subtracted from the other acquisitions.Results: All CE-MRA examinations were technically adequate for analysis with high signal noise ratio. CE-MRA accurately diagnosed stenosis (n=16) along the venous or arterial side of the fistula and graft. Thrombosis with complete occlu-sion of the graft was seen in four patients. Venous hypertension was diagnosed in four patients. Steel phenomena with decreased perfusion of the hand (n=3) and pseudo-aneurysm were easily diagnosed with CE-MRA.Conclusion: High resolution contrast enhanced MR angiography is a promising diagnostic imaging modality for diagnosis the causes of dysfunctional hemodialysis access fistula and graft and treatment planning.

C-916 MR angiography using 3-Tesla equipment and blood-pool contrast medium for preoperative planning of perforators flaps: Imaging findings from a work in progress A. Alonso-Burgos, E. Garcia-Turtor, C. Hernadez - Sastre, A. Benito, J. Zubieta; Pamplona/ES (alonso@unav.es)

Purpose: The objective of this report is to demonstrate the usefulness of angio-MR (AMR), advantages and experience using 3-tesla equipment and blood-pool contrast agent (BPCA) for preoperative planning in patients undergoing perforator flaps reconstruction. 1. To describe the AMR study protocol for preoperative plan-ning of perforator flaps reconstruction using a 3-tesla equipment and BPCA. 2. To show our experience, imaging findings, and multislice-CT angiography (angio-CT) correlation in each perforator flap.Methods and Materials: From 01/2007 to 04/2007, five consecutive patients were considered for breast reconstruction with perforator flaps: 2 superior gluteal artery and 4 deep inferior epigastric artery perforator flaps. Preoperative MRA was per-formed to localise widest perforator vessels in each procedure using a 3 T equipment and BPCA. Axial images, MPR and 3D VR images were analysed. Findings were correlated with angio-CT and surgery. Initial experience and imaging findings will be described. Content will be divided from each type of PF performed, including: 1) Location of the widest perforator vessels; 2) Main steps in surgical procedure; and 3) Pictorial essay from the AMR technical development, imaging findings and correlation with surgical procedures.Results: Identification of the main perforators was achieved in all patients with satisfactory concordance between AMR-angio-CT-surgery.Conclusion: Preoperative evaluation of perforator vessels with MRA could be feasible in patients undergoing perforator-flaps reconstruction. This technique provides a noninvasive global approach alternative to the vascular anatomy and the anterior abdominal wall structures. However, more patients need to be evaluated in order to clarify the potential aspects pointed in this report.

C-917 3 Tesla MR angographic assessment of the artery of Adamkiewicz in the work-up of aortic dissection S. Veron-Piot; Reims/FR (sophie_veron@hotmail.fr)

Purpose: The assessment of the artery of Adamkiewicz (AKA) in the pretherapeutic work-up of acute aortic dissection is an important issue. Detection of the AKA is particulary difficult when the artery arises from the false lumen of the dissected vessel. The aim of this study is to investigate the ability of 3 Tesla MRI for assess-ing the AKA in such patients.Methods and Materials: 18 consecutive patients (age range, 42-81 years; mean age, 60) underwent MR angiography on a 3 T MR unit (Achieva Philips, France, Reims). 12 patients presented with a repaired De Bakey I type aortic dissection and 6 patients with a III type aortic dissection. Contrast material enhanced three-

dimensional fast spoiled gradient recalled acquisition in the steady state (SPGR) sequence was used. Oblique sagittal sections along the posterior line of the vertebral body were performed. After injection of 15 mL, at a rate of 1 mL/sec, a series of two consecutive MR angiograms was obtained. These acquisitions were followed by a complete study of the thoracoabdominal aorta. Criteria for detection of the AKA were the morphologic “hairpin turn” criterion and “anatomic continuity” criterion.Results: In 10 of the 18 patients, as least one AKA was seen to arise from an intercostal artery. AKA was better depicted in all cases on the one minute delayed angiogram (increasing vascular signal intensity).Conclusion: 3 T MR angiography proved to be feasible in the detection of the AKA as part of a one step examination of pretherapeutic aortic dissection.

C-918 Assessing real-time vascular wall shear stress (WSS) using MRI in vivo for possible evaluation of abdominal aortic aneurysms (AAAs) and atherosclerosis S. Amirbekian, R.C. Long Jr., J. Suo, N.G. Willett, W. Taylor, D.P. Giddens, J.N. Oshinksi; Atlanta, GA/US (radiology.va@gmail.com)

Purpose: WSS in arteries contributes to a pro-atherogenic environment. Studying the hemodynamic environment in mouse models of AAAs may yield important clues about the pathogenesis and rupture of AAAs as well as atherosclerotic plaque formation and progression.Methods and Materials: In-vivo Phase-Contrast-MRI (PC-MRI) and 2D-Time-of-Flight (TOF) angiography techniques were used to obtain the blood flow velocity and accurate vessel geometry in N=15 mice. 3D-reconstructions were created. Computational-fluid-dynamics simulations were performed. Two models were created, one Rigid-Model (RM-imitating atherosclerotic vessels) with a constant diameter from the PC-MRI data and a second Compliant-Model (CM-noral vessels) based on the PC-MRI magnitude-data.Results: Supra-celiac aortic blood-flow, averaged across the cardiac cycle, was 16.9 6.3 ml/min. The infra-renal blood flow was 6.8 3.3 ml/min. Mean WSS in the aorta was 53 dynes/cm2 (range 20-180). Comparing the WSS profiles of the RM (imitating atherosclerotic vessels) and CM (normal vessels), we observed that in early systole the RM has areas of WSS values almost double the CM. From examina-tion of the WSS vector fields of these two models, we can see that the RM exhibits a greater number of areas of oscillatory shear stress than the CM. Secondly, there was reversal of the WSS vectors during early diastole in the supra-celiac aorta of the RM that was not exhibited by the CM.Conclusion: Compared to a normal compliant model, the rigid atherosclerotic model of the aorta experiences more areas of oscillatory shear stress as well as reversal of flow during diastole in the supraceliac segment where AAAs develop in mice. Correlation with biological disease markers is ongoing.

C-919 MR imaging of soft tissue venous malformations H. Rajhi, H. Jarraya, A. Salem, S. Mehiri, N. Mnif; Tunis/TN (hatem.rajhi@topnet.tn)

Purpose: Define the appearance of peripheral venous malformation at MRI and assess its role in the investigation of these lesions.Methods and Materials: Forty two patients with clinical evidence of a venous malformation, retrospectively reviewed between January 2000 and January 2007, were referred for MRI. Multisection T1 weighted spin-echo for basic anatomic evalu-ation and short inversion time in version recovery (STIR) T2 weighted sequences for evaluating the extension of the malformation were performed and completed in all cases by fat suppressed T1 weighted sequences before and after contrast materiel injection.Results: T1 weighted sequences can characterize venous malformation showing a specific gadolinium enhancement: nodular (n=18) or homogeneous extensive (n=24). T1 and STIR showed to be sufficient in characterizing these malforma-tions. In fact, the imaging features found are similar to that described on T1 and fat suppressed T1 weighted sequences before and after contrast materiel injection. Though, the primary role of MRI is to demonstrate their anatomic extent and the structures involved.Conclusion: MR imaging is excellent to establish the diagnosis when clinical findings are doubtful. It is also an adequate modality for primarily pretreatement evaluation of peripheral venous malformation extension.

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C-920 Radiological features of aortitis J. Alex1, K.T. Tan2, I.D. Lyburn1, M.C.K. Hamilton2, P. Wilde2, G. McGann1; 1Cheltenham/UK, 2Bristol/UK (jtealex@gmail.com)

Learning Objectives: After going through this exhibit, the reader should be able to: (1) understand the causes of aortitis; (2) describe the imaging findings of aortitis on computed tomography, MRI, angiography and nuclear medicine; and (3) list the differential diagnoses to aortitis.Background: Aortitis refers to inflammation of the aorta. Aortic inflammation can be caused by various diseases, including infection, trauma, connective tissue disease (including the various vasculitides) and atherosclerosis and up to 12% of surgical specimens from thoracic aneurysm surgery show signs of idiopathic aortitis. Aortitis was frequently a postmortem diagnosis before the development of advanced cross sectional imaging. However, developments in MSCT, MRI and nuclear medicine have meant that the radiologist is often the first doctor to diagnose the condition. Therefore, it is important that all radiologists are familiar with the diagnostic features of the disease.Imaging Findings: The imaging findings on the following modalities will be reviewed: (a) CT; (b) MRI; (c) PET; and (d) angiography. Other imaging features that may be related to the underlying disease, such as small vessel obliteration, microaneurysms and organ infarction, will also be discussed. The radiological differential diagnoses for aortitis, such as intramural haematoma, atherosclerosis and aortic dissection will also be discussed.Conclusion: Aortitis is an important radiological diagnosis, which can be diagnosed on imaging, but also easily missed by the unwary. The condition is often associated with other features of the underlying disease.

C-921 The acute aortic syndromes J. Alex1, K.T. Tan2, G. McGann1; 1Cheltenham/UK, 2Bristol/UK (jtealex@gmail.com)

Learning Objectives: (1) To describe the causes of the acute aortic syndrome; and (2) To describe the imaging findings of the acute aortic syndrome.Background: Patients presenting with the acute aortic syndrome are often unwell and present with severe chest and/or abdominal pain. Imaging is required both to diagnose and plan treatment of the disease. It is, therefore, important that every radiologist is familiar with the various aortic pathologies that can give rise to the syndrome. The most common of these include a leaking aortic aneurysm and aortic dissection. Rarer causes of the acute aortic syndrome include a penetrating aortic ulcer, acute intramural haematoma; aortitis; leaking/ infected aortic grafts and aortic transection.Imaging Findings: The imaging findings of the various causes of the acute aortic syndrome on CT/MRI are discussed. The abstract also gives an algorithm to the suggested imaging follow-up of patients presenting with acute aortic syndrome as this often differs among the different groups of patients.Conclusion: The acute aortic syndrome is often encountered by the general radiolo-gist as an acute emergency. However, it is easy to misdiagnose the rarer causes of the syndrome, often with disastrous consequences. In addition, different imaging follow-up strategies are required for the various causes of the syndrome.

C-922 Arteriovenous fistulas S. Baleato, R. Garcia-Figueiras, J.C. Vilanova, C. Villalva, C. Seoane, J.M. Pumar; Santiago de Compostela/ES (sandra.baleato.gonzalez@sergas.es)

Learning Objectives: 1. Identify the radiological features of arteriovenous fistulas (AVF) in different anatomic regions. 2. Review the current roles of imaging modali-ties in the evaluation of fistulas, CT, MRI and angiography. 3. Illustrate the role of interventional radiology in the management of AVF.Background: AVFs mainly involve the peripheral vascular system but can affect virtually any organ or system in the body. They can have different causes. All these features are sometimes associated with a different prognosis and they could require different therapeutic considerations.Imaging Findings: We illustrate a variety of radiological findings of AVFs on plain film, US, CT, MRI, and digital angiography in cases seen at our institution during the last 15 years. AVFs in different locations (central nervous system, thorax, abdomen, musculoskeletal system, and peripheral vascular system) are shown.

Conclusion: Familiarity with the spectrum of imaging findings is essential in the accurate interpretation of AVF. Radiologists could play a critical role in the diagnosis and treatment of AVFs. Digital angiography is helpful in elaborating a vascular map for an endovascular treatment.

C-923 Contrast-enhanced three-dimensional MR angiography of upper limbs: From thoracic inlet to fingertips M.E. Nazar, A. Nápoli, P. Batezatti, C. Morales, H. Di Nunzio, C.H. Bruno; Buenos Aires/AR (menazar@arnet.com.ar)

Learning Objectives: To illustrate the findings of upper limb vascular pathology by contrast-enhanced MR Angiography, to propose this method as an alternative to conventional angiography, and to describe its advantages and limits, based on a casuistic of 53 patients.Background: To date, few studies have been reported concerning upper limb vasculature, which reflect the difficulty in identifying the region’s vascular anatomy. In this exhibit, we will detail the most significant findings regarding upper limb vascular pathology, based on our experience with 53 patients from January 2003 to May 2007.Procedure Details: All patients underwent MRA with gadolinium in a 1.5 T unit; conventional angiography was performed in 22 of them. Gadolinium was adminis-tered by injection pump at 1.4 ml/sec average flow rate. One sequence used was RF-FAST, with the following parameters: TE, 2.5 ms; TR, 6 ms; slice thickness, 2-3 mm; gap, 0 mm; flip angle, 50°. The other sequence was 3D-FFE, with the following parameters: TE, 1.34 ms; TR, 4.7 ms; slice thickness, 1.3 mm; gap, 0; matrix, 352 x 352 /448 x 512; FOV, 400 x 400. Additionally, we performed T1 W axial sequences with and without fat suppression, T2 W, STIR and T1 W post gadolinium.Conclusion: Contrast-enhanced MR angiography is an extremely useful method to evaluate upper limb vasculature. It allows assessing the vascular tree with high resolution, determining intrinsic and extrinsic causes compromising upper limb circulation.

C-924 Development and congenital abnormalities of the portal venous system R. Shuto, H. Kiyosue, R. Takaji, S. Tanoue, S. Matsumoto, H. Mori; Oita/JP

Learning Objectives: 1. To understand normal development of the portal venous system. 2. To describe the characteristic clinical and imaging findings of various congenital abnormalities. 3. To understand etiology of various developmental abnormalities of the portal venous system.Background: Congenital anomaly of the portal venous system are rare but can cause serious symptoms. It is important to know the etiology and characteristic findings of various types of congenital anomaly for diagnosis and treatment of these anomalies.Procedure Details: We reviewed the cases with portal venous anomalies, including agenesis/hypogenesis of the portal vein, portal venous aneurysm, preduodenal portal vein, intrapancreatic portal vein, intra/extrahepatic portosystemic venous shunt, and congenital arterioportal shunt. The characteristics of these anomalies could be clearly depicted on ultrasonography, CT, MRI and angiography. The etiology of these anomalies could be understood by considering the embryol-ogy of the portal venous system. Some of them could be successfully treated by endovascular techniques.Conclusion: In this exhibit, we demonstrate normal and anomalous development of the portal venous system and describe characteristic clinical and imaging findings of congenital portal venous anomalies. The knowledge of the etiology and char-acteristic findings of these anomalies would be useful for diagnosis and treatment of the portal venous diseases.

C-925 Imaging of systemic manifestations of vasculitis A. Luna1, R. Ribes2, S. Rossi3, L.C. Da Cruz4, I. Rodriguez1, E. Ramón5; 1Jaén/ES, 2Córdoba/ES, 3Buenos Aires/AR, 4Rio de Janeiro/BR, 5Madrid/ES

Learning Objectives: To discuss the importance of imaging in the management of systemic vasculitis. To describe the radiologic manifestations of systemic vasculitis in the different organs/systems.Background: Systemic vasculitis are classified according to the size of the involved vessels: large vessels (giant cell arteritis, Takayasu arteritis), medium-sized vessels (polyarteritis nodosa, Kawasaki disease, primary granulomatous central nervous

system vasculitis), or small vessels (Wegener granulomatosis, Churg-Strauss syndrome, microscopic polyangiitis, Henoch-Schönlein syndrome, systemic lupus erythematosus, rheumatoid vasculitis, Behçet syndrome). Major areas of involve-

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ment include: central nervous system, cardio-vascular, gastrointestinal, pulmonary, genitourinary and musculo-skeletal systems. Patterns of presentation of vasculitis are not well described in the radiology literature, even though they have a wide extension in every radiology subspecialty because of its multisystem involvement and the wide age range of affected patients. The role of imaging in the monitoring of treatment is also not well established in the literature.Imaging Findings: A system/organ approach is used to analyze the manifesta-tions of vasculitis, including an analysis of the most adequate imaging techniques according to the involved area. Cross-sectional imaging plays a key role in the analysis of vasculitis in the different organs. Involvement of large and medium size vessels are well depicted with angiographic techniques. MR has a great sensitivity to detect vessel wall inflammation and it is of help in the monitorization of response to treatment.Conclusion: Imaging, and specially CT and MR, are useful in the detection and characterization of the multisystem manifestations of vasculitis. Post-treatment monitorization may also benefit for imaging follow-up.

C-926 Vascular complications of tuberculosis from head to foot A. Seith, S. Subramanian, H. Kandpal; New Delhi/IN (drsubbusmc@yahoo.co.in)

Learning Objectives: To illustrate the imaging spectrum of vascular complications of tuberculosis from head to foot.Background: Vascular complications in tuberculosis are uncommon and may devel-op as a result of direct intravascular seeding or of extension from contiguous focus. Imaging findings in patients with vascular complications have been illustrated.Imaging Findings: CNS: Tubercular meningitis causes obliterative endarteritis of the intracranial vessels. CT and MRI show enhancing exudates in the basal cisterns and infarcts in the brain supplied by the affected vessel. Chest: Lymph nodal involvement can cause compression of SVC or thrombosis of SVC leading to superior vena caval syndrome. Tubercular pseudo aneurysm may develop in the wall of the aorta. In addition, fibrosing mediastinitis may develop and CT shows ill-defined soft tissue mass in the mediastinum encasing and narrowing SVC and the pulmonary artery. Pulmonary parenchymal involvement causes pulmonary artery occlusion and hypertrophy of bronchial artery causing massive hemoptysis. Abdomen: Lymph nodal involvement around porta hepatis can lead to extrinsic narrowing or occlusion of the portal vein leading to cavernoma formation. Splenic vein thrombosis can lead to the development of short gastric collaterals. IVC and aorta can be encased by lymphnodes in the retroperitoneum. Thrombosis of IVC leading to limb edema and ascites can occur. Peripheral vessels: Stenosis or pseudo aneurysm can develop in the peripheral vessels.Conclusion: Tuberculosis can involve vessels in various parts of the body leading to significant morbidity and mortality. Knowledge of imaging findings in patients with vascular complication of tuberculosis is necessary for the proper diagnosis and management of these patients.

C-927 Causes of inferior vena cava thrombosis: A pictorial essay S.C.P.C. Dias, L.F.P. Gonçalves, H. Torrão, S. Kurochka, C. Leite, V.S. Mendes; Braga/PT (silviacostadias@hotmail.com)

Learning Objectives: To systematize and illustrate the spectrum of causes re-sponsible for inferior vena cava (IVC) thrombosis. To discuss ways to avoid and to detect artifactual fillings defects.Background: IVC thrombosis may occur due to a bland thrombus, extrinsic com-pression (nontumoral causes), tumoral invasion or intrinsic IVC tumor (tumoral causes). The most frequent cause is a bland thrombus, which may be idiopathic or reflect a hypercoagulable state, venous stasis or the presence of a foreign body. Many conditions can be responsible for extrinsic compression of the IVC with concurrent thrombus formation, the most common one being retroperitoneal adenopathies. Tumoral invasion of the IVC is usually related to renal cell carcinoma. Others malignancies may extend directly into the IVC, like hepatocellular and adrenalcortical carcinoma. Primary tumors of the IVC can also be a rare cause of IVC thrombosis.Imaging Findings: We selected a group of cases from our department that illus-trate the different etiologies for IVC thrombosis: 1) an extensive IVC thrombosis associated with supra-hepatic and renal vein thrombosis in a 38-year-old female patient with a history of oral contraceptive use; 2) a metastized cecum carcinoma with retroperitoneal adenopathies that compressed the IVC; 3) a left renal tumor that invaded the IVC and extended up to the right atrium; 4) a leiomyosarcoma in a female patient with concomitant extensive pulmonary thromboembolism.Conclusion: Various causes of IVC thrombosis can be detected in the imaging studies. Their characterization and distinction from pseudothrombosis may influence the management of these patients.

C-928 Diagnosis of acute mesenteric ischemia with different radiological modalities: A pictorial review M. Reiss-Zimmermann, D. Fritzsch, T. Kahn; Leipzig/DE (martin.reiss-zimmermann@medizin.uni-leipzig.de)

Learning Objectives: To learn the symptom patterns, disadvantages/advantages of CT, MRI, US and DSA and improvement of diagnostics by using post-process-ing features.Background: Because of its high mortality rate, acute mesenteric ischemia is still one of the most life-threatening causes of acute abdomen complex, which is mainly diagnosed in patients over the age of 65 and constitutes 1-8 % of all acute abdomens. Prognosis depends on the ischemic extent as well as on co-factors like age, morbidity of the patient and the time at which therapy began. Besides rare causes (vasculitides, intoxication) the main reason is a thrombembolic occlusion of the proximal mesenteric arteries. Less frequently are venous pathologies which result from reduced mesenteric blood flow at a state of shock trying to compensate for hypotension.Procedure Details: Using multislice CT (MSCT), the imaging of the whole abdomen can be acquired in a short time. Examination should be planned in two phases using a bolus tracking in the first phase resulting in a CT angiography (CTA). Multiplanar reconstructions (MPR) are easily made and can be very helpful. Alternate radio-logical procedures like DSA, ultrasound and MRI can be helpful. The indications as well as disadvantages/advantages are discussed.Conclusion: Because of its fast acquisition of the whole abdomen, possible supple-mentary CTA without additional contrast agent and optional MPR, MSCT is the first-choice diagnostic method for acute mesenteric ischemia. The main advantage of DSA is that it is a concomitant diagnostic and interventional modality. Ultrasound and MRI can be helpful in additional diagnostics.

C-929 Imaging manifestations and pitfalls of cerebral venous ischemia A. Hasanefendioglu Bayrak1, E. Kara2, Y. Özpeynirci3, S. Albayram3, N. Kocer3, C. Islak3; 1Diyarbakir/TR, 2Mersin/TR, 3Istanbul/TR (aylin_has@yahoo.com)

Learning Objectives: To illustrate the wide imaging spectrum of venous ischemia with various cases and different modalities like CT, CT venography, MRI, MRI venography and DSA. It is aimed to present images of patients who had normal or variant anatomy, and pitfalls.Background: Cerebral venous ischemia is a serious neurological pathology, although less common than arterial tromboemboli. Because of various underlying causes, different clinical manifestations and reversible nature of the disease with early diagnosis, imaging plays an important role in the diagnosis of the disease.Imaging Findings: We observed thromboses and recanalization of the sinuses, parenchymal edema with effacement of the sulcus, prominent medullary veins, thalamic edema and hemorrhage, decreased ADC, etc. Aplasia or hypoplasia of the sinuses, variants of confluence sinuum, arachnoid granulations, different flow patterns (especially for MRI), technical pitfalls of MRI venography, idiopathic intracranial hypertension, which can mimic or accompany venous ischemia, were evaluated as pitfalls of cerebral venous ischemia in the images of several cases. Limitations of each modality were reviewed.Conclusion: To make a diagnosis, it is important to know normal venous anatomy and its variants, different radiological findings and pitfalls. Also the limitations of different modalites should be kept in mind.

C-930 Hypertrophied bronchial and non-bronchial systemic arteries in hemoptysis: MDCT and DSA illustration of common variants M. Gupta, D.N. Srivastava, A. Seith, R. Gupta; Delhi/IN (drmuditgupta@yahoo.co.in)

Learning Objectives: To illustrate the common variants of abnormal bronchial and non-bronchial systemic arteries, causing hemoptysis, on MDCT and DSA.Background: : Hemoptysis is a serious emergency. Bronchial artery embolization (BAE) is the treatment of choice in acute conditions. However, bronchial arteries are variable in their origin and course. In few patients, non-bronchial arteries are the culprits. MDCT can depict the anatomy of abnormal arteries and thus guide interventional procedures. It has the potential of replacing flush aortogram during DSA. Imaging spectrum of abnormal bronchial and non-bronchial arteries causing hemoptysis are illustrated along with their angiographic appearance.Imaging Findings: Hypertrophied bronchial arteries appear as enhancing nodular structures at the hila on axial CECT, but it is difficult to appreciate their course. Volume rendered and MIP images exquisitely show their origin, as well as the course. Bronchial arteries are considered abnormal when their diameter exceeds 2 mm or if they can be traced up to the hila. A spectrum of variants of bronchial arteries including right and left bronchial, right and left intercostobronchial trunk

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and common trunk, as well as ectopic bronchial arteries, abnormal non-bronchial arteries such as internal mammary, lateral thoracic, intercostal and inferior phrenic arteries are illustrated. Embolization was performed and abnormal arteries were confirmed on DSA, which are illustrated.Conclusion: MDCT, with various reconstructions, is able to depict the origin and anatomy of orthotopic as well as ectopic bronchial and non-bronchial systemic arteries. Hence, it provides a detailed roadmap of thoracic vasculature to guide focused and efficient interventional procedure with better patient outcome and decreased complication rates.

C-931 Pulmonary arteriovenous malformations: From diagnosis to treatment A. Khalil, C. Nedelcu, L. Sahel, J. Korzec, C. Marsault, M.-F. Carette; Paris/FR (antoine_khalil@yahoo.fr)

Learning Objectives: 1. How I perform MDCT and CE-MRA in patients with pulmonary arteriovenous malformations (PAVMs). 2. Diagnosis criteria and pitfalls in chest X-ray, MDCT and CE-MRA of PAVMs. 3. PAVM and Rendu-Osler-Weber (ROW) disease: Genetics supports. 4. Pathophysiology of complications of PAVMs. 5. Why, when and how I treat the PAVMs. 6. Tips and tricks of trans-catheter vaso-occlusion (TCVO) of PAVMs. 7. Follow-up: Timing, methods and treatment. 8. Particular situations: Pregnancy, diffuse PAVM.Background: Unenhanced MDCT is the gold standard for detection and follow-up in patients with PAVM. In some cases, the CE-MRA could be helpful as in young patients or in renal failure. Worsening of symptoms during pregnancy in ROW disease occurs frequently. TCVO of PAVM is the treatment of choice to prevent complications.Imaging Findings: Aspects of PAVM are single pulmonary nodule with feeding and draining vessels or serpiginous mass with vascular connections. Differential diagnosis includes nodules and abnormal trajectory of pulmonary vein. PAVM has a predilection for the sub-pleural and lower lobes. Surgery is no longer the right treatment option for patients with PAVM, especially in ROW disease.Conclusion: Non-invasive imaging modalities (MDCT and CE-MRA) are accurate for diagnosis, pre-therapeutic evaluation and follow-up in patient management with PAVM. TCVO of PAVM is accurate and safe with a low rate of recurrence.

C-932 Imaging features and differential diagnosis of non-atherosclerotic arterio-occlusive lesions affecting the origins of the great vessel and the head and neck arteries P. Govender, I.M. Brennan, H.G. Delaney, C. Farrelly, J.F.M. Meaney; Dublin/IE

Learning Objectives: To illustrate the spectrum of non-atherosclerotic lesions affecting the aortic arch, origins of the great vessel and the carotid and vertebral arteries.Background: The vast majority of vascular lesions affecting the aortic arch, origins of the great vessel and the carotid and vertebral arteries are due to atherosclerosis. Although less common, non-atherosclerotic lesions frequently have a distinctive appearance, which should point towards the correct diagnosis.Causes include mycotic aneurysms, inflammatory arthritis (giant cell and Takayasu’s arteritis and Behcets syndrome), primary dissection either arising within the aorta and propagating distally or arising de-novo within the head and neck arteries, traumatic lesions (pseudoaneurysms and dissection), tumour compression or invasion and radiotherapy-induced changes.Imaging Findings: We illustrate the spectrum of findings on cross-sectional MR images, contrast-enhanced MRA, CT angiography, catheter angiography and duplex sonography. In particular, we emphasise the nature of the mural abnormality on routine and fat-suppressed images, which should point to the correct diagnosis.Conclusion: We present the imaging findings and differential diagnosis of non-atherosclerotic lesions affecting the aortic arch, origins of the great vessel and the carotid and vertebral arteries.

C-934 Multidetector CT vs. color Doppler US for planning breast reconstructive surgery with deep inferior epigastric artery perforators A. Cina, L. Barone Adesi, M. Salgarello, L. Bonomo; Rome/IT

Purpose: MDCT has recently proposed as accurate tool for preoperative mapping of deep inferior epigastric artery perforators (DIEP) employed for breast reconstruc-tion. No data are still available to compare MDCT with the established standard technique: color-Doppler US (CDUS). 1) To briefly describe the DIEP surgery and the role of diagnostic imaging; 2) to assess the accuracy of multidetector CT (MDCT) vs color-Doppler US for the identification of the DIEP; and 3) to evaluate the time-cost of both techniques.

Methods and Materials: 25 women underwent MDCT and CDUS for planning DIEP surgery. Blind evaluation of MDCT and CDUS was performed before surgery. Surgical findings are employed as gold standard. Accuracy of MDCT vs CDUS was assessed in detection and mapping of the dominant and three best perforators.Results: The best perforator, effectively employed for surgical reconstruction, was identified in 25/25 cases (100%) by CDUS and in 23/25 (92%) by MDCT. Perforators evaluated at surgery as adequate for reconstruction were identified in 64/71 cases by CDUS (90.1%) and in 68/71 cases (95.7%) by MDCT. Mean time for examination and mapping was 24 min for CDUS and 21 for MDCT.Conclusion: Both techniques resulted adequate for planning DIEP surgery. Global accuracy of MDCT is high, although not superior to CDUS for detection of the best perforator. CDUS can be still employed as reference technique, if an expert operator is available. If a dedicated US operator is not available or if CDUS is doubtful or panoramic anatomical information are required, MDCT can be recommended.

C-935 64 multidetector computed tomography angiography (64MDCTA) vs. digital subtraction angiography (DSA) in the evaluation of peripheral arteries: Personal experience F. Pozzi-Mucelli, S. Cernic, A. Pellegrin, R. Pizzolato, M.A. Cova; Trieste/IT

Purpose: To evaluate the potential of 64 MDCTA in the detection of significant lesions of lower extremities of inflow and runoff arteries.Methods and Materials: 55 patients (39 men, 16 women; mean age 71.7) with pe-ripheral arterial occlusive disease underwent both 64MDCTA and DSA evaluations of arterial tree from infrarenal aorta to supramalleolar region. CT parameters were 64x0.5 mm collimation, 0.3 mm increment/rotation (pitch 0.828) and 0.5-1.0 mm reconstruction interval. Axial CT scans, maximum intensity projection, volume rendering and multiplanar oblique reformatted images were independently reviewed by three readers for the degree of stenosis. Findings were graded according to four categories of stenosis: 1 (0-49%); 2 (50-99%); 3 (occluded); and 4 (unable to visualize). DSA was the standard of reference.Results: In 55 patients, a total of 1155 segments were evaluated (infrarenal aorta and 16 arterial segments for each leg: 23 bilateral and 27 monolateral comparison). We found agreement for the degree of stenosis in 92.8% and discrepancy for 7.2%. Comparing DSA versus CT angiography, this one showed sensitivity of 95.3 %, and specificity of 96.5%, positive predictive value of 91%, negative predictive value of 98.2% and diagnostic accuracy of 96.2%.Conclusion: 64MDCTA is helpful in detecting hemodynamically significant lesions in peripheral arterial occlusive disease. The results of 4 and 16 MDCTA were fur-thermore refined; however, a critical point is the presence of diffuse calcifications below the knee arteries.

C-936 Hereditary hemorrhagic telangiectasia (Osler-Rendu-Weber disease): Imaging findings in abdominal involvement L. Curvo-Semedo, J. Brito, A. Canelas, P. Belo-Oliveira, A. Gil Agostinho, E. Pinto, V. Carvalheiro, F. Caseiro-Alves; Coimbra/PT (rdd61333@mail.telepac.pt)

Purpose: To review and describe the imaging manifestations of abdominal visceral involvement in hereditary hemorrhagic telangiectasia (HHT).Methods and Materials: The database review of our institution retrieved 27 patients (11 male, 16 female; age range: 24-97 years old, median age: 66 years old) with the diagnosis of HHT in the last fifteen years based on the presence of at least 3 Curaçao criteria: family history (n=16), epistaxis (n=22), mucocutaneous telangiectasia (n= 22) and visceral involvement (n= 21). Imaging studies from the 21 patients were reviewed regarding abdominal visceral involvement. Patients were studied by US (including Döppler-US) (n=16), CT (n=5), DSA (n=5), MRI (n=2) and also through endoscopic studies (n=18).Results: Fourteen out of 21 patients (67%) had involvement of abdominal viscera all showing GI tract lesions, most commonly found in the stomach (12 cases). All vascular malformations were depicted on endoscopic studies but only in one case on dynamic CT and in two other patients by DSA. The liver was involved in 7 cases and the pancreas in one. Imaging signs were represented by vascular shunting, small telangiectases and/or larger vascular malformations.Conclusion: Information about the abdominal involvement in patients with HHT is instrumental since it carries an increased risk of developing serious haemorrhagic complications. Despite the frequency of GI vascular abnormalities they are less commonly depicted by cross-sectional techniques compared to endoscopic studies. On the contrary, liver lesions are easily appreciated on contrast-enhanced dynamic studies, whereas pancreatic involvement is rarely found.

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C-937 Role of duplex US and contrast enhanced MR angiography in the assesment of critical carotid stenosis M.A. Gelabert, R. Martinez, A.M. Quiles, M. Boada, E. Rosello, S. Remollo, S. Pedraza, J. Serena; Girona/ES (arantxagelabert@hotmail.com)

Purpose: To expose our experience in the preoperative evaluation of critical carotid stenosis with carotid duplex US and MR angiography. To evaluate the role transcranial US plays as an additional technique.Methods and Materials: We retrospectively examined 100 consecutive patients who underwent endarterectomy in our center. The surgical indication was taken by a multidisciplinary team based on the presence of symptoms (transient ischemic attack or stroke) and the presence of a carotid stenosis 70% assessed in most cases by noninvasive methods (carotid duplex ultrasound scanning and contrast enhanced MR angiography). Concordance between both noninvasive techniques was evaluated. In addition, clinic and epidemiologic variables, presence of contra-lateral stenosis, transcranial US findings, patient outcome and MR angiography and duplex US findings at three months post-endarterectomy were also registered.Results: A high concordance rate (94%) between duplex ultrasound scanning and contrast enhanced MR angiography was found. In three out of the six discordant findings, the MR angiography suggested stenosis 70% but was 70% in duplex US. The transcranial US detected an attenuated flow pattern suggestive of critical carotid stenosis in three out of the 6 cases. The post-endarterectomy carotid duplex US showed 1.5% carotid oclusions and 6% of no critical restenosis. The morbility and mortality rates were 4 and 3%, respectively.Conclusion: Noninvasive imaging techniques are mainstay in endarterectomy indication in patients with cerebrovascular strokes. Our analysis shows a high con-cordance rate between carotid duplex US and contrast enhanced MR angiography. In discordant cases, transcranial US might be useful.

Vascular

US

C-938 Vascular imaging with contrast-enhanced ultrasound: Abdominal aorta and arteries of the neck and the lower extremities H. Moschouris1, D. Kalikis1, P. Goutzios2, D. Matsaidonis1; 1Piraeus/GR, 2Athens/GR (hipmosch@in.gr)

Learning Objectives: To familiarise the radiologist with the technique and the findings of contrast-enhanced ultrasonography (CEUS) of the abdominal aorta, neck and lower extremity arteries.Background: Despite the extensive use of grey-scale and Color Doppler (CD) ultrasonography in vascular imaging, there are some limitations that often preclude a definitive diagnosis. CEUS could be applied immediately after the aforementioned methods, in order to overcome some of these limitations.Imaging Findings: A last generation ultrasound contrast agent (SonoVue, Bracco) is utilised in order: (a) to enhance Doppler signals (“Doppler rescue” technique), or (b) to image the vessels with a dedicated, contrast-specific algorithm (Contrast-Tis-sue Imaging, CnTI). Typical cases of vascular pathology are demonstrated, such as aortic aneurysm (intact and ruptured), aortic dissection, occlusions and stenoses of neck and lower extremity arteries. Several remarkable features of vascular CEUS are depicted including detailed delineation of lumen and thrombus in aneurysms, extravasation of contrast in cases of rupture, abnormal flow within the false lumen and delineation of the flap in cases of dissection. CEUS can confirm an arterial occlusion (commonly affecting the internal carotid or superficial femoral artery and suspected by CD) and differentiate between total and near-total occlusion. CEUS can also provide better visualisation of both normal and diseased vessels that cannot be studied adequately with CD because of slow flow, tortuosity, deep location or patient’s body habitus.Conclusion: CEUS can easily increase the confidence of ultrasonographic diag-nosis in many cases of vascular pathology.

C-939 Ultrasound of vascular anomalies of the skin: A pictorial essay C.I. Whittle, G. Pose, S. Seguel, G. Baldassare, G. Soto Giordani, F. Carreno; Santiago/CL (carolinaw@mi.cl)

Learning Objectives: Show the main ultrasound characteristics that help in the differential of vascular anomalies of soft tissues.Background: Vascular anomalies are frequent in childhood, 1/100 kids need evaluation because of them. They are classified into tumors (hemangiomas) and vascular malformations. Usually, hemangiomas have spontaneous regression. Vascular malformations do not involute spontaneously and may need treatment. An accurate differential diagnosis is essential to define the best management. We present a series of vascular lesions diagnosed by US, including hemangioma, and arteriovenous, venous and lymphatic malformations.Imaging Findings: Hemangiomas are benign endothelial neoplasms. Usually as superficial lesions, they appear in the first month of life, show fast growth, stability and posteriorly an involutive phase. On US, they are well-defined solid tumors, echo-genic, hypoechogenic or heterogenous. Arterial and venous flows are present.Congenital hemangiomas are fully developed at birth. Two types are described: RICH (rapidly involuting) and NICH (not involuting). They are more heterogenous, with calcifications in 17% of cases. Vascular malformations are congenital anoma-lies. They can present at birth, childhood or adolescence. They are classified into high flow (arteriovenous malformation) or slow flow (venous, capillary, lymphatic or mixed malformations). They are compressible. No mass is noted with US. Mul-tiple tubular tortuous vascular structures conform to a vascular nidus with arterial, venous or both flows present. They may have flebolites. Lymphatic malformations are fine-walled uni or multilocular lesions, with no flow.Conclusion: US is the method of choice for the initial evaluation of vascular anoma-lies and allows differentiation of hemangiomas from vascular malformations.

C-940 Color Doppler ultrasound of renovascular hypertension: How to perform and handle it R. Basilico, M. Romano, G. Patriarca, M. Storto; Chieti/IT (r.basilico@radiol.unich.it)

Learning Objectives: 1) To describe color Doppler US examination protocol in patients referred for renovascular hypertension. 2) To illustrate the various US scans and resulting images of normal main, accessories and parenchymal renal arteries. 3) To review US findings of renal artery stenosis. 4) To learn the causes of false positive and false negative US findings of renal stenosis.

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Background: Color Doppler US examination has the potential to be a screening test for renovascular hypertension, but the main disadvantage is its low diagnostic accuracy together with the high rate of technically inadequate examinations. The knowledge of appropriate US scans is useful in decreasing the number of technically inadequate color Doppler examinations of renal arteries, as well as being aware of false positive and false negative US findings of renal artery stenosis reduces the number of mistakes.Imaging Findings: Various US scans of normal main renal arteries, accessories and parenchymal renal arteries with different transducer positions and patient posi-tions are described and illustrated with relative US images and Doppler findings. Sample cases of renal artery stenosis detected at Color Doppler US, by also using US contrast agents, and compared to other imaging modalities are presented. False positive and false negative Doppler US findings of renal artery stenosis are shown and correlated with other imaging modalities.Conclusion: A color Doppler US-standardized technique is crucial in order to obtain an adequate examination of renal arteries in the evaluation of patients suspected to have renovascular hypertension and, consequently, to decrease the number of unnecessary CT/ MR angiography.

C-941 Volumetric high frequency Doppler ultrasound enables the assessment of early antiangiogenic therapy effects on tumor xenografts in nude mice M. Palmowski, M. Jugold, J. Huppert, E.C. Woenne, W. Semmler, F. Kiessling; Heidelberg/DE (m.palmowski@dkfz.de)

Purpose: The sensitivity of Doppler ultrasound below 10 MHz to assess early an-tiangiogenic therapy effects in animal tumor models has been shown to be limited. Thus, our aim of was to investigate the potential of high-frequency volumetric power Doppler ultrasound (HF-VPDU) for monitoring those treatments.Methods and Materials: Squamous cell carcinoma xenografts grown in nude mice were scanned with HF-VPDU at a center frequency of 30 MHz. Images with 200μm slice thicknesses were recorded and merged to a 3-dimensional dataset of which the relative color pixel density was determined. Animals received either VEGFR2-antibodies or 0.9% NaCl and were examined at day 0, 3 and 6 of treat-ment. After the last examination, tumors were resected and their vascularization characterized by immunohistology.Results: At day 6, no significant difference in volumes of treated and untreated tumors was observed yet. In contrast, mean tumor-vascularisation in treated ani-mals had decreased to 44%, while in the control group it had increased to 152% (p 0.01). In correspondence, vessel density as determined by CD31 staining was 0.19 0.10% in treated and 0.92 0.41% in untreated tumors (p 0.01). Additionally, the fraction of mature (SMA positive) vessels increased under therapy.Conclusion: HF-VPDU is capable of depicting early changes of tumor vascularisa-tion during antiangiogenic therapy.

C-942 Deep venous thrombosis: Is routine serial ultrasonography necessary? D. Mondal, R.M.S. Carter, J. Woodhouse, J. Amarnath, N. Graham; Milton Keynes/UK (dipanjali_mondal@hotmail.com)

Purpose: Ultrasonography is accurate for revealing femoral and popliteal vein thrombus but less sensitive and specific for deep vein thrombosis (DVT) confined to the calf. Rescanning within 1-7 days has been proposed to identify patients who develop extension of thrombosis into the proximal veins. Approximately, 80% of suspected DVT have negative findings on initial ultrasound and require a repeat scan. This audit investigates whether a positive rescan rate of 4%, based on local standards at a tertiary hospital, is currently being achieved at our institution.Methods and Materials: Serial Doppler ultrasonography reports for clinical suspi-cion of DVT over a six month period were reviewed using the hospital computerised radiology information system. Findings from the initial phase of the audit were disseminated to key clinical workers to increase awareness of the pathway for investigating DVT. A DVT algorithm was devised based on a clinical scoring system (Wells score) and the D-Dimer biochemical assay. A re-audit followed reviewing clinical serial Doppler ultrasonography rates as above.Results: Serial ultrasonography detected above-knee DVT in 2/110 (1.8%) patients. Re-audit showed a pick-up rate of 0/80 (0%) patients. There were 8 (10%) cor-rectly repeated scans, 5 (7%) incorrectly repeated scans and 8 (10%) incorrectly not repeated scans.Conclusion: The pick-up rate for DVT on serial ultrasonography is too low a yield to justify serial ultrasonography routinely. Re-audit showed no improvement despite attempts to increase awareness of the pathway for investigating DVT. Further educa-tion period is required with future planned re-audits to achieve our goals.

C-943 Contrast enhanced ultrasound (CEUS) in the assessment of carotid plaque vascularization: Correlation with the vessel density in the inmunohistochemical study R. Gilabert, N. Bargalló, N. Solanes, J. Ramirez, A. Garcia-Criado, V. Riambau; Barcelona/ES (gilabert@clinic.ub.es)

Purpose: Neovascularization within the atherosclerotic plaques is associated with infiltration of inflammatory cells and plaque vulnerability. To determine whether CEUS can identify and determine the amount of plaque vascularization present in advanced carotid plaques.Methods and Materials: Five consecutive patients with carotid stenosis 70% scheduled to carotid endarterectomy were studied with contrast enhanced ultra-sound (SonoVue 2.4 ml) with a 15 MHz transducer using low mechanical index (Siemens Sequoia, CPS software). Vascularization on CEUS was graded: Grade 0, no vascularization; Grade I, bubbles limited to the plaque adventitia and /or shoulder; Grade II, bubbles reaching the plaque core; Grade III, extensive contrast enhance-ment throughout the plaque. The findings of the CEUS study were correlated with the histopathologic and inmunohistoquimic analysis (plaque vessel density with CD31). Vessel wall density was graded: Grade 0, no vessels; Grade I, 50 ves-sels/mm2, Grade II 50 vessels/mm2; Grade III 100 vessels/mm2.Results: CEUS detected the periadventitial vasavasorum and plaque vasculariza-tion in all patients (Grade II, 2 patients; Grade III, 3 patients). Agreement between the CEUS and plaque vessel density with CD31 was observed in all but 1 patient (Grade II, CEUS; Grade III, CD31 vessel wall density).Conclusion: This preliminary data shows that CEUS can depict the presence and extent plaque and arterial wall vascularization. Further studies are warranted in order to determine: 1) the predictive value of CEUS for identifying patients at risk for plaque progression or developing symptoms, 2) the applicability of CEUS in pharmacologic trials.

C-944 A comparison of the value of the ultrasound tests assessing the degree of atherosclerosis in diabetic patients A. Rotkiewicz, P. Grzelak, B. Wozniakowski, C. Wolski, L. Stefanczyk; Lodz/PL (rotkiewicz@wp.pl)

Purpose: Morphological changes during atherosclerosis are preceded by functional abnormalities of vascular endothelium. Subclinical stage of atherosclerosis can be visualized with ultrasound. Diagnostic value of such examinations has not yet been clearly established. Therefore, the purpose of this study was: 1. Assessment of carotid IMT and vascular reactivity in diabetic subjects. 2. Assessment of cor-relations between IMT and vascular reactivity measured by ultrasound functional tests. 3. Usefulness assessment of above-mentioned tests in diagnosis of early-stage atherosclerosis.Methods and Materials: 56 male diabetics, aged from 21 to 64 were examined. 4 tests were performed: intima-media thickness (IMT) measurement and 3 functional tests for the evaluation of vessels reactivity: effort-mediated (EMD), flow-mediated (FMD) and nitric-mediated dilatation (NMD) of brachial artery. Pearson or Spearman correlation with an estimation of significance level was used to evaluate relation-ship between features.Results: IMT correlated with age much stronger than with duration of diabetes. Strong association was found between EMD and IMT. FMD showed strong correla-tion with age and weaker with IMT. The association of NMD with age and duration of diabetes was statistically significant but weaker than those between EMD and FMD. The relationship between NMD and IMT was weak.Conclusion: 1. IMT correlates well with age and weaker with duration of diabetes in male diabetics. 2. FMD and EMD strongly correlate with age and weaker with duration of diabetes. 3. IMT assessment and ultrasound functional tests may be useful tools to identify the increased predisposition to atherosclerosis, also before age of 30 years.

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