Appendix A

Units and Constants

Energy 1 electron volt (eV) = 1.602 x 10- 12 erg 1 kiloelectron volt (keV) = 1.602 x 10-9 erg 1 million electron volts (Me V) = 1.602 X 10-6 erg 1 joule (J) = 107 ergs 1 watt (W) = 107 ergs/s

1 rad

1 gray (Gy)

1 sievert (Sv)

1 horsepower (HP) 1 calorie (cal)

Charge 1 electronic charge

1 coulomb (C) 1 ampere (A)

Mass and Energy 1 atomic mass unit (amu)

1 electron rest mass 1 proton rest mass 1 neutron rest mass 1 pound

Length

= 1 J/s = 1 x 10- 2 J/kg = 100 ergs/g = 100 rad = 1 J/kg = 100 rem = 1 J/kg = 746W = 4.184 J

= 4.8 X 10- 10 electrostatic unit = 1.6 x 10- 19 C = 6.28 X 1018 charges = 1 Cis

= 1.66 X 10-24 g = 1/12 the atomic weight of 12C

= 931 MeV =0.511 MeV = 938.78 MeV = 939.07 MeV = 453.6 g

1 micrometer, or micron Cum) = 10-6 m = 104 A

186

1 nanometer (nm) 1 angstrom (A) 1 fermi (F) 1 inch

Activity 1 curie (Ci)

1 millicurie (mCi)

1 microcurie {J.lCi)

1 becquerel (Bq)

1 kilobecquerel (kBq)

1 megabecquerel (MBq)

1 gigabecquerel (GBq)

1 terabecquerel (TBq)

Constants A vogadro's number

Planck's constant (h) Velocity oflight IT

e

Appendix A. Units and Constants 187

= 10-9 m = 10-8 cm = 10-13 cm = 2.54cm

= 3.7 X 1010 disintegrations per second (dps) = 2.22 x 1012 disintegrations per minute (dpm) = 3.7 x 107 dps = 2.22 X 109 dpm = 3.7 x 104 dps = 2.22 X 106 dpm = 1 dps = 2.703 X 10- 11 Ci = 103 dps = 2.703 X 10- 8 Ci = 106 dps = 2.703 X 10- 5 Ci = 109 dps = 2.703 X 10-2 Ci = 1012 dps = 27.03 Ci

= 6.02 X 1023 atoms/g· atom = 6.02 x 1023 molecules/g· mole = 6.625 x 10-27 erg· s/cycle = 3 x 1010 cm/sec = 3.1416 = 2.7183

Appendix B

Terms Used in Text

Absorption. A process by which the total energy of a radiation is removed by an absorber through which it passes.

Accelerator. A machine to accelerate charged particles linearly or in circular paths by means of an electromagnetic field. The accelerated particles such as!Y. particles, protons, deuterons, and heavy ions possess high energies and can cause nuclear reactions in target atoms by irradiation.

Accuracy. A term used to indicate how close a measurement of a quantity is to its true value.

Annihilation radiation. y-Radiations of 511 keV energy emitted at 1800 after a [3+ particle is annihilated by combining with an electron in matter.

Atomic mass unit (amu). By definition, one twelfth of the mass of l~C, equal to 1.66 x 10-24 g or 931 MeV.

Atomic number (Z). The number of protons in the nucleus of an atom. Attenuation. A process by which the intensity of radiation is reduced by

absorption and/or scattering during its passage through matter. Attenuation coefficient. The fraction of y-ray energy attenuated (absorbed

plus scattered) per unit length of an absorber (linear attenuation co­efficient, J1.) or per gram of an absorber (mass attenuation coefficient, J1.m)·

Auger electron. An electron ejected from an energy shell, instead of a charac­teristic x-ray, carrying the energy equal to that of the x-ray.

Average life (r). See Mean life. Avogadro's number. The number of molecules in 1 g' mole of any substance

or the number of atoms in 1 g' atom of any element. It is equal to 6.02 x 1023•

Binding energy. The energy to bind two entities together. In a nucleus, it is the energy needed to separate a nucleon completely from other nucleons in the nucleus. In a chemical bond, it is the energy necessary to separate two binding partners an infinite distance.

Biological half-life (7;,). The time by which one half of an administered dose of a substance is eliminated by biological processes such as urinary and fecal excretions.

188

Appendix B. Terms Used in Text 189

Bremsstrahlung. y-Ray photons produced by deceleration of charged parti­cles near the nucleus of an absorber atom.

Carrier. A stable element that is added in detectable quantities to a radio­nuclide of the same element, usually to facilitate chemical processing of the radionuclide.

Carrier-free. A term used to indicate the absence of any stable atoms in a radionuclide sample.

Collimator. A device to confine a beam of radiation within a specific field of view. Collimators may be converging, pinhole, diverging, and parallel-hole types.

Collimator efficiency. The number of photons passing through the collimator for each unit of activity present in a source.

Collimator resolution. A component of spatial resolution of an imaging sys­tem contributed by the collimator. It is also called geometric resolution.

Committed dose equivalent (HT •SO )' The dose equivalent to organs or tissues of reference (T) that will be received from an intake of radioactive material by an individual during the 50-year period following intake.

Compton scattering. In this process, a (-ray transfers only a partial amount of energy to an outer orbital electron of an absorber, and the photon itself is deflected with less energy.

Conversion electron (e-). See Internal conversion. Critical organ. See Organ, critical. Cross section (a). The probability of occurrence of a nuclear reaction or the

formation of a radionuclide in a nuclear reaction. It is expressed in a unit termed barn; 1 barn = 10- 24 cm 2 •

Curie (Ci). A unit of activity. A curie is defined as 3.7 x 1010 disintegrations per second.

Dead time. The period of time that a counter remains insensitive to count the next after an event.

Decay constant ().). The fraction of atoms of a radioactive element decaying per unit time. It is expressed as ). = 0.693/t 1/2 , where t1/2 is the half-life of the radionuclide.

Veep-dose equivalent (Hd)' Dose equivalent at a tissue depth of 1 cm (1000 mg/cm 2 ) resulting from external whole-body exposure.

Dose. The energy of radiation absorbed by any matter. Also, a general term for the amount of a radiopharmaceutical administered in microcuries or millicuries.

Dosimeter. An instrument to measure the cumulative dose of radiation re­ceived during a period of radiation exposure.

Dosimetry. The calculation or measurement of radiation absorbed doses. Effective half-life CT.). Time required for an initial administered dose to be

reduced to one half as a result of both physical decay and biological elimi­nation of a radionuclide. It is given by T" = (Tp x 1/,)/(Tp + 1/,), where T" is the effective half-life, and Tp and 1/, are the physical and biological half­lives, respectively.

190 Appendix B. Terms Used in Text

Electron (e-). A negatively charged particle rotating around the atomic nu­cleus. It has a charge of 4.8 x 10-10 electrostatic units and a mass of 9.1 x 10-28 g, equivalent to 0.511 MeV, or equal to 1/1836 of the mass of a proton.

Electron capture (EC). A mode of decay of a proton-rich radionuclide in which an orbital electron is captured by the nucleus, accompanied by emis­sion of a neutrino and characteristic x-rays.

Electron volt (eV). The kinetic energy gained by an electron when accelerated through a potential difference of 1 V.

Energy resolution. Capability of a detecting system to separate two y-ray peaks of different energies. It is given by the full width at half maximum (FWHM) of a given photopeak.

Erg. The unit of energy or work done by a force of 1 dyne through a distance of 1 cm.

Fission (f). A nuclear process by which a nucleus divides into two nearly equal smaller nuclei, along with the emission of two to three neutrons.

Free radical. A highly reactive chemical species that has one or more un­paired electrons.

Generator, radionuclide. A device in which a short-lived daughter is separated chemically and periodically from a long-lived parent adsorbed on adsor­bent material. For example, 99mTc is separated from 99Mo from the Moly generator with saline.

Gray (Gy). The unit of absorbed radiation dose in SI units. One gray is equal to 100 rad.

Half-life (t 1/ 2 ). A unique characteristic of a radionuclide, defined by the time during which an initial activity of a radionuclide is reduced to one half. It is related to the decay constant ), by t 1/2 = 0.693/),.

Half-value layer (HVL). The thickness of an absorbing material required to reduce the intensity or exposure of a radiation beam to one half of the initial value when placed in the path of the beam.

Internal conversion. An alternative mode to y-ray decay in which nuclear excitation energy is transferred to an orbital electron, which is then ejected from the orbit.

Ion. An atom or group of atoms with a positive charge (cation) or a negative charge (anion).

Intrinsic efficiency. The number ofradiations detected divided by the number of radiations striking the detector.

Intrinsic resolution. A component of the spatial resolution of an imaging system that is contributed by the detector and associated electronics and depends on the photon energy, detector thickness, and the number of PM tubes.

Isobars. Nuclides having the same mass number, that is, the same total num­ber of neutrons and protons. Examples are ~~Fe and ~~Co.

Isomeric transition (IT). Decay of the excited state of an isomer of a nuclide to a lower excited state or the ground state.

Appendix B. Terms Used in Text 191

Isomers. Nuclides having the same atomic and mass numbers but differing in energy and spin of the nuclei. For example, 99Tc and 99mTc are isomers.

Isotones. Nuclides have the same number of neutrons in the nucleus. For example, lUI and lUXe are isotones.

Isotopes. Nuclides having the same atomic number, that is, the same number of protons in the nucleus. Examples are I~C and I~C.

LDso 30' A quantity of a substance that, when administered or applied to a group of any living species, kills 50% of the group in 30 days.

Linear energy transfer (LET). Energy deposited by radiation per unit length of the matter through which the radiation passes. Its usual unit is ke V / /lm .

. \tass defect. The difference between the mass of the nucleus and the com­bined masses of individual nucleons of the nucleus of a nuclide .

. \Jass number (A). The total number of protons and neutrons in a nucleus of a nuclide .

. Weanlife (r). The average expected lifetime of a group of radionuclides before disintegration. It is related to the half-life and decay constant by r = 1/). =

L44t I 2'

.\1 etastable state (m). An excited state of a nuclide that decays to the ground state by the emission of ,'-radiation with a measurable half-life .

. \1odulation transfer function. A quantitative value of the spatial resolution of an imaging system .

. Veutrino (\'). A particle of no charge and mass emitted with variable energy during f3+, and electron capture decays of radionuclides. An anti neutrino (V) is emitted in f3- decay .

. Vo carrier added (NCA). A term used to characterize the state of a radioac­tive material to which no stable isotope of the compound has been added purposely.

Nucleon. A common term for neutrons or protons in the nucleus of a nuclide. Organ. critical. The organ that is functionally essential for the body and

receives the highest radiation dose after administration of radioactivity. Organ, target. The organ intended to be imaged and expected to receive the

greatest concentration of administered radioactivity. Pair production. i-rays with energy greater than 1.02 Me V interact with the

nucleus of an absorber atom, and a positron and an electron are produced at the expense of the photon.

Photoelectric effect. A process in which a {-ray, while passing through an absorber, transfers all its energy to an orbital electron, primarily the K­shell electron of an absorber, and the photoelectron is ejected from the shell.

Photofraction. The fraction of all detected {-rays that contributes to the photopeak.

Physical half-life (Tp). See Half-life. Precision. A term used to indicate the reproducibility of the measurement of

a quantity when measurements are made repeatedly. Quality factor (QF). A factor dependent on linear energy transfer that is

192 Appendix B. Terms Used in Text

multiplied by absorbed doses to calculate the dose equivalents in rem. It is used in radiation protection to take into account the relative radiation damage caused by different radiations. It is 1 for x-, y-, and f3-rays and 10 for neutrons and protons.

Rad. The unit of radiation-absorbed dose. One rad is equal to 100 ergs of radiation energy deposited per gram of any matter, or 10- 2 J/kg of any matter.

Range. The straight line distance traversed by a charged particle in an absorber.

Relative biologic effectiveness (RBE). A factor used to calculate the dose equi­valent in rem from rad. It is defined as the ratio of the amount of a stan­dard radiation that causes certain biological damage to the amount of radiation in question that causes the same biological damage.

Roentgen. The quantity of x- or y-radiations that produces one electrostatic unit of positive or negative charge in 1 cm3 of air at O°C and 760-mm Hg pressure (standard temperature and pressure, STP). It is equal to 2.58 x 10-4 Cjkg air.

Roentgen equivalent man (rem). A dose equivalent defined by the absorbed dose (rad) times the relative biological effectiveness or quality factor of the radiation in question.

Scintillation scanning or imaging. Recording of the distribution of radioactiv­ity in the body or a section of the body by the use of a Nal(Tl) detector to form an image.

Scintigraphy. A photographic recording of the distribution of radioactivity in an area of interest in the body by the use of a gamma camera.

Sensitivity. The number of counts per unit time detected by an imaging device for each unit of activity present in a source. It is expressed in cps/ /lCi.

Shallow-dose equivalent (Hs). Dose equivalent at a tissue depth of 0.007 cm (7 mg/cm2 ) averaged over an area of 1 cm 2 from external exposure to the skin.

Sievert (Sv). The SI unit of dose equivalent and equal to 100 rem. Spatial resolution. A measure of the ability of an imaging device to faithfully

reproduce the image of an object. It is given by the modulation transfer function (MTF) and is determined by the Fourier transform of the line spread function.

Specific activity. The amount of radioactivity per unit mass of a radio nuclide or labeled compound.

Specific ionization. The number of primary and secondary ion pairs produced by an incident radiation per unit path length in an absorber.

Thermal neutron. Neutrons of thermal energy 0.025 eV.

Appendix C

Answers to Questions

Chapter 2

3.81.3% 7. 130keV

Chapter 3

1. (a) 1.11 x 1015 atoms (b) 0.24 pg

2. (a) 4.75 x 1014 dpm (b) 216 Ci or 7.99 x 1012 Bq

3.6.97 hr 4. (a) 429 mCi (15.9 GBq)

(b) 120.7 mCi (4.46 GBq) 5.25.5 hr 6.4.03 days 7.6.41 mCi (237.2 MBq) 9.330 min

10.63% 11. 1.32 hr 12. N/2 13.168.3 (6.23 GBq)

Chapter 4

3. (a) 1707 ± 13.8 cpm (b) 1647 ± 14.9 cpm

4. 40,000 counts

193

194 Appendix C. Answers to Questions

5. 3 standard deviations 6. 1111 counts

Chapter 5

8. 665 mCi (24.6 GBq) 9. 8.92 mCi (330 MBq)

Chapter 6

15. (a) 7.32 HVLs (b) 8 HVLs

17.10 HVLs 18.2.31 em 19.2 mm

Chapter 8

8. (a) 25% (b) 50%

14.61.4%

Chapter 9

1. (b) 130 em/min 6. (c) 1911 counts/cm 2

Chapter 10

6. (e) 0.35

Chapter 13

1. 36,541 rad (365.4 Gy) 2. 350 rem (3.5 Sv) 7. 18,144 J.lCi· hr 8. 1.06 x 10- 2 J.lCi· hr 9. 1.2 rad

Chapter 14

4. (a) 0.5 Rjhr (b) 6.96 mm Pb

6.1.77 mm Pb 7.10%

Appendix C. Answers to Questions 195

Index

Aberration, chromosome, 142 Absorbed dose, 158-166, 167-171

annual limit on intake (ALI), 168 committed dose equivalent, 167, 189 deep-dose equivalent, 168, 189 effective dose equivalent, 168 shallow-dose equivalent, 168, 192 total effective dose equivalent, 168 weighting factor, 168

Absorbed fraction, 159 Absorber

half-value layer, 61 linear attenuation coefficient of, 58 linear energy transfer of radiations in,

52 mass attenuation coefficient of, 59 ranges of radiations in, 53

A bsorption of}' radiations, 58 Accidental coincidence in PET, 133

correction for, 134 Accuracy, 34, 188 Activity, 21

radioactivity, 21 units of, 26

Agreement states, 175 ALARA, program, 176 Alpha «(X) decay, 14 Aluminum breakthrough test, 49 Analog-to-digital converter (ADC), 104 Anger scintillation camera, see Gamma

camera Annihilation radiations, 17, 55, 80, 188

coincidence detections in PET, 131 escape peaks, 80

Annual limit on intake (ALI), 168 Antineutrino, 14, 191 Atom, 3

binding energy of electron of, 5 composition of, 3 electronic structure of, 3-5 structure of the nucleus of, 6

Atomic mass unit, 1, 3 Atomic number, 6 Attenuation of ,-radiations, 58-62

half value layer and, 61,190 in PET, 132 in SPECT, 129 linear attenuation coefficient, 58 mass attenuation coefficient, 59 tenth value layer and, 61

Auger electron, 13, 188 Auger process, 13 Autofluoroscope, 105 Avalanche ionization, 66 A verage value, 34 Avogadro's number, 24, 46,187

Backprojection in tomography, 125 Backscatter peak, 79 Backscattering of y rays, 57, 78 Bar phantom, 111 Becquerel (Bq), 26 Beta (fr) particle, 14

average energy of, 15 decay, 14 energy spectrum of, 15 range of, 53

198 Index

Binding energy, 188 nuclear, 7 of electron, 5

Bioassay, 179 Biologic half-life, 25, 188 Bismuth germanate (BGO) detectors,

132 Bit, 104 Blur, III Bragg ionization peak, 52 Bremsstrahlung, 54

lie (Carbon-II), 44, 132 Cadmium-tellurium detector, 83 Calibration

dose calibrator, 69 high voltage or energy, in well

counter, 89 survey meter, 72

Carcinogenesis by radiation, 151-152 risk of, 151

Carrier, 41 Carrier-free, 41 Cataractogenesis, 153 Caution signs and labels, 178 Cell survival curve, 144-149

Do, 145 Dq ,145 effects of dose rate on, 146 effects of LET of radiations on, 147 effects of radioprotectors on, 149 effects of radiosensitizers on, 147 extrapolation number n, 146 oxygen effect on, 147

Cells, 138-140 chromosome, 138 composition of, 138 cycle, 139 cytoplasm, 138 DNA synthesis, 140 gene, 138 meiosis, 139 mitosis, 139 nucleus, 138 survival curve, 144

Center of rotation in SPECT, 129, 135

Central nervous system death, 150

Chain reaction, nuclear, 42 Characteristic x rays, 6, 13, 19

peaks, 79 Charged particles

interaction of, with matter, 51 linear energy transfer (LET), 52 ranges, 53

Chart of the nuclides, 8 Chromosome aberration, 142 Chromosome in cells, 138 Coincidence circuit in liquid

scintillation, 81 Coincidence detection

accidental or random, 133 correction, in PET systems, 134

liquid scintillation counter, 81 Collimators, 95, 100

converging, 95,100 diverging, 100 efficiency of, 116 fan beam, 100, 110 focal length of, 95 focal point, 95 focused, for rectilinear scanner, 95 for thyroid probe, 91 holes, 95, 100 parallel hole, 100-101, 108-110 pinhole, 100 resolution of, 108-111 septal thickness, 95, 108

Color quenching, 82 Committed dose equivalent, 167, 189 Compton edge, 78 Compton electron, 56 Compton plateau, 78 Compton scattering, 56 Compton valley, 78 Computers

in digital scintigraphy, 104 in SPECT, 125

Confidence level in statistics, 35 Constants and units, 186 Contrast, image, 119-120

film contrast and, 119 patient motion and, 120 scatter radiations and, 119

Control rods, reactor, 42 Converging collimator, 95, 96, 100

fan beam, 100, 110

Conversion electron, see Internal conversion

Counting, statistics of, see Statistics of counting

Counting of radioactivity, 90 differential, 76 integral, 76

Cross section in nuclear reaction, 45, 189 Cumulated activity in dosimetry, 161 Cumulative radiation dose, 160 Curie (Ci), 26, 187 Cyclotron, 40-42

cyclotron-produced radionuclides, 40 equation for production of

radionuclid.:!s,45 targets, 45

Dead time, 87-88, 189 GM counters, 71, 87 in nonparalyzable systems, 87 in paralyzable systems, 87 losses, 87 pulse pileup, 87 scintillation cameras. 88

Decay constant, 21, 189 Decay of radionuclides, 11-20

alpha (l), 14 beta (Pl, 14-17 electron capture. 18-19. 190 equations, 21-23, 29-32

general, 21- 23 successive, 29-32

half-life, 23, 190 isomeric transition (IT), 11-14, 190 mean life, 25, 191 positron or P+, 17-18 schemes, 15 secular equilibrium, 31 successive decay, 29-32 transient equilibrium, 30 units of radioactivity, 26

Decay scheme of radionuclide, 15 Deep-dose equivalent, 168, 189 Delta rays, 51 Deoxyribonucleic acid, 138 Department of Transportation, 182 Detection efficiency, 85, 86

geometric efficiency, 86

Index 199

intrinsic efficiency, 85 photopeak efficiency or photofraction,

86 Detectors

bismuth germanate (BGO), 132 cadmium-tellurium, 83 gas-filled, 65- 72 liquid scintillation, 73, 81 NaI(TI), 73, 74, 99 of scintillation cameras, 99 semiconductor, 83 solid scintillation, 73

Differentiated cells, 143 Digital computer, 104 Digital image, 104

acquisition modes for, 104 matrix sizes in, 104

Dilution quenching, 82 Direct action of radiation, 143 Disintegration rate, 21 Display or storage, 76

for scintillation cameras, 103 Distance in radiation protection, 171 Diverging collimator, 100 Dos and don'ts in radiation protection,

175 Dose

Calculation in internal dosimetry, 158

calibrators, 68-70 accuracy, 69 constancy, 69 geometry, 69, 70 linearity, 69 quality control, 69

equivalent, 141 limits, 170 rate, 158

effect of, on cell survival, 146 Dosimeter

pocket, 70 thermoluminescent, 174

Dosimetry, internal radiation, see Internal radiation dosimetry

Double break in chromosome, 142 Double escape peak, 80 Doubling dose, see Genetic effects of

radiation Dynode of photomultiplier tube, 75

200 Index

EC, see Electron capture decay Edge packing, 118 Effective dose equivalent, 168 Effective half-life, 25, 189 Electromagnetic radiations, 2

frequency, 2 wavelength,2

Electron capture (EC) decay, 18, 190 Electron volt, 2 Electronic collimation in PET, 132 Electronic structure of atom, 3 Electrons, 3-6, 190

Auger, 13, 188 binding energies,S, 7, 188 conversion, 12

Embryologic damage by radiation, 153 Emission computed tomography, 124

PET,131-135 SPECT,125-131

Energy, I and mass units, 1 calibration of well counter, 89 transition (decay), 14

Energy resolution, 84, 190 Equilibrium, 30-32

secular, 31 transient, 30

Equilibrium dose constant, 159, 162 Errors, 34

random, 34 systematic, 34

Escape peak double, 80 iodine, 79 single, 80

Excitation of atoms, 6, 51 Excited states, 11 Exponential decay, 23 Exposure rate, in survey meter, 177 Exposure rate constants, 171

18F (Fluorine-I 8), 44, 132, 172 Fetus, effects of radiation on, 153 Film badge for personnel monitoring,

173 Film contrast, 119 Filter, ramp, in computed tomography,

128

Fission, 43 and radio nuclide production, 43

Fluorescence yield, 14 Focal-plane tomography, 124 Focused collimators for rectilinear

scanners, 95 Forces, nuclear, 7 Fourier transform in computed

tomography, 129 Frame mode of data acquisition,

104 Free radical, 143, 190 Frequency, 2

of electromagnetic radiation, 2 spatial, 114

Full width at half maximum, 85, 113

67Ga (Gallium-67), 44,61,172 68Ga (Gallium-68), 44, 172 Gain, amplification, 75 Gamma camera, 97 -105

collimators, 100 console, 98 contrast, 119 detector, 99 digital computer, 104 display and recording system, 103 head,98 mobile, 99 multicrystal, 105 photomultiplier (PM) tube, 101 pulse height analyzer (PHA), 103 sensitivity, 116 collimator efficiency, 116 spatial resolution, 107

collimator, 108 evaluation of, III intrinsic, 107 scatter, 110

thin detector, 100 tomography with, 125 quality control tests, 120 uniformity in, 117 X, Y-positioning circuit, 101

Gamma ray emission, 11 Gas-filled detectors, 65-75

Geiger-Miiller counter, 70 Geiger region, 66

ionization chambers, 68 Cutie pie survey meter, 68 dose calibrator, 68 pocket dosimeter, 70

proportional counter, 66 proportional region, 66 region of continuous discharge, 67 region of recombination, 65 region of saturation, 65

Gastrointestinal death, 150 Gaussian distribution, 35 Geiger- M tiller (G M) counters, 70-72

avalanche, 66 counting efficiency, 71 dead time, 71, 87 quenching in, 70

Generators, radionuclide, 47-49 aluminum breakthrough, 49 99Mo_ 99mTc generator, 48 molybdenum breakthrough, 49

Genetic effects of radiation, 154-156 doubling dose, 154 genetically significant dose, 155

Geometric efficiency, 86 in photopeak detectors, 86 in scintillation counter, 116

Germanium-lithium [Ge(Li)] detector, 83

Gray (Gy), 140, 190

3H (Tritium), 44,181 Half-life, in radioactive decay, 23-25,

190 biologic, 25 definition, 23 effective, 25 physical, 23

Half-value layer (HVL), 61,190 Hemopoietic death, 150 Hine- Duley phantom, 112

1231 (iodine-l23), 44 1251 (iodine-125), 44 131 1 (iodine-131), 44

decay scheme of, 16 Image distortion by converging and

diverging collimators, 101

Image reconstruction, 125 IllIn (indium-Ill), 44

decay scheme of, 18

Index 201

Indirect action of radiation, 143 Information density, 97

definition, 97 Interaction of radiations with matter,

51-62 Internal conversion, 12, 190

characteristic x ray, 6, 13, 19 conversion electron, 12 in electron capture, 19 in isomeric transition, 12

Internal radiation dosimetry, 158-166

absorbed dose in SI units, 161 absorbed fraction, 159 cumulated activity, 161 dose calculation, 158 dose rate, 158 equilibrium dose constant, 159 mean absorbed dose, 161

Intrinsic resolution of scintillation camera, 107, 190

Iodine escape peak, 79 lon, 190 Ionization, 6, 51

by charged particles, 51 primary, 51 secondary, 51 specific, 52

Ionization chambers, 68-70 Cutie Pie survey meter, 68 dose calibrator, 68-70 pocket dosimeter, 70

Ionizing radiations, 51 Isobars, 8, 190 Isomeric transition, 11, 190 Isomers, 8,11,191 Isotones, 8, 191 Isotope selectors, 69, 103 Isotopes, 8, 191

K absorption edges, 56 K shell, 3 K shell binding energies, 5 K x-rays, 13 Kinetics of radioactive decay, 21-33

202 Index

Lead shielding, 79, 173 Lead x-ray peak, 79 Licenses for use of radio nuclides, 175

general license, 175 specific license of broad scope, 176 specific license oflimited scope, 176

Life-shortening effect of radiation, 152 Line of stability of nuclides, 7 Line spacing in rectilinear scanning,

97 Line spread function (LSF), 113

spatial resolution and, 113 Linear amplifier, 75 Linear attenuation coefficient of

absorber, 58 Linear energy transfer, 52, 191

definition, 52 effects of, in radiation, 147

Liquid scintillation counters, 81 applications of, 82 counting efficiency, 82 primary solute, 81 quenching, 82 scintillator, 81 secondary solute, 82 solubilizer, 82 solvent, 81 wavelength shifter, 82

List mode data acquisition, 104 Lithium-drifted detectors, 83 Long-term effects of radiation, 150-156

genetic effect, 154 somatic effect, 151

Lower level discriminator in radiation detectors, 7

Magic numbers, 6 Major organogenesis, effects of

radiation, 153 Mass and energy, 1 Mass attenuation coefficient, 59 Mass defect in nucleus, 8, 191 Mass number, 6,191 Matrix in computers, 104 Mean absorbed dose per cumulated

activity, 161 Mean life of radio nuclide, 25,191 Mean value, 35

Medical cyclotrons, 41 Medical uses of radioactive materials,

177 Metastable states of nucleus, 191 99Mo_99mTc generators, 48

aluminum breakthrough, 49 99Mo breakthrough, 49

Moderators in reactors, 42 Modifying factor in radiation

protection, 141 Modulation transfer function (MTF),

114 Molybdenum-99, 43, 44, 48

decay scheme of, 16 fission product, 43, 44

Monitoring, personnel, 173 Multichannel analyzer (MCA), 76 Multicrystal camera, 105 Multiformat imaging, 103 Multihole focused collimator in

rectilinear scanning, 95, 96 Multiple radio nuclide counting, 24,

90 Mutations, 142

and doubling dose, 154 genetic, 154 spontaneous, 154

13N (Nitrogen-B), 44, 132 NaI(Tl) detectors, 74

in scintillation cameras, 99 in thyroid probes, 91 in well counters, 88 properties of, 74

NaI(Tl) well counters, 88 detection efficiency of, 91 effect of sample volume, 89 energy calibration, 89 shielding, 89

NCA, see No carrier added Neutrino, 17, 191 Neutron number, 6 Neutrons, 3, 6

characteristics of, 3 fast, 42 interaction of, in matter, 62 mass of, 3 thermal, 42, 192

Neutron activation analysis, see Neutron capture reactions

Neutron capture reactions, 43 No carrier added (NCA), 41, 191 Noise

background in LS counting, 81 effect of, on image contrast, 119 in SPECT, 130

Nonparalyzable counting systems, 87 Nonpenetrating radiations, 171 NRC (Nuclear Regulatory Commission),

175 Nuclear binding energy, 7 Nuclear chain reaction, 42 Nuclear fission, 42, 43 Nuclear forces, 7 Nuclear reactors, 42

equation for production of radionuclides, 45

principles of, 42 production of radionuclides in, 42

Nuclear Regulatory Commission, 175 Nucleons, 3 Nucleus, 3, 6

binding energy of, 7 line of stability, 7 liq uid drop model of, 6 metastable state of, 8 notation for, 6 radius of, 3 shell model of, 6

Nuclides, 8 chart of, 8 definition of, 8

150 (Oxygen-15), 44, 132 Occupational dose limits, 170 Orbital electrons, 3-5 Organ, critical, 191 Organ, target, 191 Oxygen-15, 44, 132 Oxygen effect, 147 Oxygen enhancement ratio, 147

32p (Phosphorus-32), 44,54, 173 Packaging in transportation of

radioactive material, 182

Index 203

Pair production, 57 Parallel hole collimators, 100

classification of, 109 in scintillation cameras, 100 performance parameters of, 108 resolution, 108 sensitivity, 116

Paralyzable counting systems, 87 Parent-daughter decay, 29 Particulate radiations, definition of, 1 Patient motion, 120

effects of, on image contrast, 120 Penetrating radiations, 171 Persistence oscilloscope, 103 Personnel monitoring, 173 PET systems, 131 Phantoms, 111-112

bar, III Hine-Duley, 112

Photocathode of photomultiplier tubes, 75

Photodisintegration, 58 Photoelectric effect, 55 Photofraction, 86 Photomultiplier (PM) tubes, 75, 101

in LS counting, 81 in scintillation cameras, 101 in scintillation counters, 75 in thyroid probe, 91 in well counters, 89

Photons, 2, 6 annihilations, 18,55,80 attenuation of, 58 Compton scattering of, 56 definition of, 6 interactions of, 55 pair production of, 57 photoelectric effect of, 57

Photopeak, 77 efficiency, 86 energy resolution of, 85

Pinhole collimator, 100 Pixels, 104 Placards in transportation of

radioactive material, 183 Planck's constant, 2, 187 Pocket dosimeter, 70 Polaroid film, 103 POPOP, in liquid scintillation, 82

204 Index

Positron emission tomography (PET), 131-135

annihilation coincidence detection in, 131

attenuation correction in, 132 detectors in, 132 electronic collimation, 132 quality control tests, 135 random coincidences, 133 sensitivity of, 135 spatial resolution, 134

Positrons (r), 17 annihilation of, 18,55, 80 decay, 17

Preamplifiers, 75 Precision, 34, 191 Pregnancy

effects of radiation, 153 radiation dose limits, 170 lO-day rule, 154

Preimplantation stage, effects of radiation, 153

Prodromal stage, 149 Propagation of errors, 37 Proportional counters, 66 Protons, 3

atomic number, 3 properties of, 3

Pulse height analyzers (PHA), 76, 103 discriminator settings, 76 gamma cameras, 103 liquid scintillation counter, 81 multichannel,76 principles of operation of, 76 single channel, 76 spectrum, 77 well counters, 89 window settings, 76

in rectilinear scanners, 97 in scintillation cameras, 103

Pulse pileup, 87

Quality control tests dose calibrators, 69 scintillation cameras, 120 SPECT and PET, 135

Quality factor (QF), 141, 191 Quantum number, 3-5

Quenching in GM counters, 70 in liquid scintillation counting, 82

R (roentgen), 140, 192 Rad, 140, 192 Radiation(s)

absorption of, 58 effects ofradiation on man, 149-156

genetic, 154 somatic, 151

electromagnetic, 2 ionizing, 51 monitoring of, exposure, 173 non penetrating, 171 particulate, 1 penetrating, 55, 171

Radiation area, 168 high radiation area, 168 very high radiation area, 168

Radiation biology, 138-166 Radiation detectors

cadmium-telluride, 83 detection efficiency of, NaI(TI), 85 energy resolution of NaI(TI), 84 gas-filled, 65-72 liquid scintillation, 81 NaI(Tl),74 semiconductor, 83 thyroid probe, 91 well type, 88

Radiation dose, see Internal radiation dosimetry

Radiation dose limits, 170 Radiation dosimetry, internal, see

Internal radiation dosimetry Radiation effects

carcinogenesis, 151 cataractogenesis, 153 cell survival curves, 144-146 central nervous system death, 150 chemicals, effects of, 147 chromosome aberration, 142 differentiated cells and, 143 direct action, 143 dose rate and, 146 doubling dose, 154 genetic effects, 154

genetically significant dose, 155 gastrointestinal death, 150 hemopoietic death, 150 indirect action, 143 in utero, 153 linear energy transfer and, 147 long-term, 150 oxygen effect, 147 radioprotectors, 149 radio sensitizers, 147 short-term, 149 spontaneous mutation, 154 stage of cell cycle, 149 tissue sensitivities, 143 undifferentiated cells and, 143

Radiation protection, 167-175 activity, 173 ALARA,I77 definition of terms, 167 distance, 17 dos and don'ts in, 175 film badge, 173 personnel monitoring, 173 principles of, 171 radiation dose limits, 170 shielding, 173 sources of radiation exposure, 169 thermoluminescent dosimeters, 174 time, 171

Radiation regulations, 175-183 agreement state, 175 ALARA,177 Department of Transportation, 182 dose calibrator, 177 high radiation area, 168 licenses, 175

general license, 175 specific license of broad scope, 176 specific license of limited scope,

176 medical uses of radionuclides, 177 Nuclear Regulatory Commission

(NRC),175 radiation area, 168 radiation safety committee, 176 radiation safety officer, 176 radioactive waste disposal, 180 record keeping, 182 survey for contamination, 177

Index 205

survey for exposure rate, 177 survey meters, 177

Radiation Safety Committee, 176 Radiation Safety Officer, 176 Radiation units, 140 Radioactive decay

annihilation radiation in, 18 antineutrino in, 14 Auger electron, 13 Auger process, 13 by alpha particle (IX) emission, 14 by beta minus (fr) emission, 14 by electron capture (EC), 18 by positron Ur) emission, 17 calculation related to, 27 characteristic x ray, 6, 13 conversion electron, 12 decay constant, 21 decay equations, 21, 29 effective half-life, 25 exponential, 23 fluorescence yield, 14 half-life, 23 internal conversion, 12 isomeric transition, 11 mean life, 25 neutrino, 17 of mixed radionuclide sample, 24 secular equilibrium, 31 specific activity, 26 successive decay, 29 transient equilibrium, 30 transition energy, 14

Radioactive decay equations, 21 successive, 29

Radioactive packages, receiving and monitoring, 179

Radioactive spill, 181 Radioactive waste disposal, 180-181

decay in storage, 180 incineration, 181 release into sewerage system, 180 transfer to authorized recipient, 181

Radioactivity calculation related to, 27 decay equations, 21 definition, 21 successive decay equations, 29 units of, 26

206 Index

Radionuclide(s) cyclotron produced, 40 decay of, 11 definition of, 8 medical uses of, 177 production of, 40 reactor produced, 42

Radionuclide generators, 47 99Mo_99mTc generator, 48

Radioprotectors, 149 Radiosensitivity of cells and tissues, 143 Radiosensitizers, 147 Ramp filter in computed tomography,

128 Random coincidences in PET, 133 Random errors, 34

standard deviations and, 34 Ranges of charged particles in absorber,

53, 192 Reactors, nuclear, 42

chain reaction, 42 control rod, 42 equation for production of

radionuclides, 45 fission, 42, 43 moderators, 42 neutron capture reaction, 43 reactor-produced radionuclides, 42 targets, 45

Receiving of radioactive packages, 179 Reconstruction, image, 125

in SPECT and PET, 125 Record keeping in NRC regulations, 182 Rectilinear scanners, 95-97

focused collimator, 95 information density, 97 photorecording, 97 principles of operation of, 96 spatial resolution, III

Region of recombination in gas ionization, 65

Regulations, radiation, see Radiation regulations

Relative biological effectiveness, 141 Rem (roentgen equivalent man), 141 Resolution, energy, 84 Resolution, spatial, see Spatial

resolution

Restitution, 142 Restricted areas and unrestricted areas,

168 Roentgen (R), 140, 192 Rubidium-82,44, 132

S, mean absorbed dose, 161 Saturation factor in production of

radionuclides, 46 Scatter radiations

Compton, 56 effect of, on spatial resolution, 110 in PET, 133 in SPECT, 130

Scatter resolution, 110 Scintillation camera, see Gamma camera Scintillation detectors, 73

detection efficiency, 85 energy resolution, 84 for rectilinear scanner, 95 for scintillation camera, 99 for thyroid probe, 91 for well counter, 88 geometric efficiency, 87 intrinsic efficiency, 85 intrinsic resolution, 107 NaI(Tl) detectors, 74 photofraction, 86 photopeak efficiency, 86

Scintillation solvents, liquid, 81 Secondary electrons, 51 Secular equilibrium in successive decay,

31 Semiconductor detectors, 83 Sensitivity

in PET, 135 in scintillation camera, 116 in SPECT, 131

Septal penetration, 108 Septal thickness, 108 Sewerage disposal of radioactive waste,

180 Shallow dose equivalent, 168, 192 Shell model of nucleus, 6 Shielding in radiation protection, 173 Sievert (Sv), 141, 192 Silicon detectors, 83

Single break in chromosome, 142 Single channel analyzer (SCA), 76 Single escape peak, 80 Single photon emission computed

tomography (SPECT), see SPECT

SI units gray, 140, 190 radioactivity, 26 rem, 141, 192

Sodium iodide detectors, see Scintillation detectors

Sodium iodide well counter, 88 Source organs, 158 Sources of radiation exposure, 169 Spatial frequency, 114 Spatial resolution, 107-116, 192

collimator resolution, 108 evaluation of, 111-116

bar phantoms in, III line spread function in, 113 modulation transfer function in,

114 intrinsic resolution, 107 limits of, in PET, 134 limits of, in SPECT, 130 scatter resolution, 110

Specific activity of radionuclide, 26, 192 Specific ionization, 52, 192 SPECT, 125-131

attenuation correction, 129 factors affecting, 129 principles of, 125 reconstruction of image, 125

back projection, 125 sensitivity, 131 spatial resolution, 130

Spectrometry, gamma ray, 76-80 backscatter peak, 79 characteristic x ray, 79 coincidence or sum peak, 80 Compton edge, 78 Compton plateau, 78 Compton valley, 78 double escape peak, 80 energy resolution, 84 iodine escape peak, 79 photopeak, 77

single escape peak, 80 spectrum, 76

actual, 77 ideal, 77

Index 207

Spontaneous discharge in gas ionization, 67

Spontaneous mutations, 154 Standard deviation, 34 Statistics of counting, 34-39

accuracy, 34 errors, 34 Gaussian distribution, 35 percent standard deviation, 36 precision, 34, 191 propagation of errors, 37 standard deviation of count rate, 36 standard deviation of counts, 34

Straggling of range, 53 Successive decay of radionuclides, 29 Survey for contamination and exposure

rate, 177 Survey meters, 177

Cutie pie, 68 Geiger-Muller, 70

Survival curves, cell, see Cell survival curve

System Internationale (SI) unit becquerel, 26 rad, 140 rem, 141

Systematic errors, 34

Target in production of radionuclides, 45

Target, organ, 191 Technetium-99m (99ffiTc), 44

characteristics of, 44 decay scheme of, 12 exposure rate constant of, 172 generator, 48 half-value layer of Pb for, 61

Tenth value layer (TVL) of absorber, 61 Terms used in the text, 188 Thallium-201 e01Tl), 44

exposure rate constant, 172 half-value layer, 61

Thermal neutrons, 42, 192

208 Index

Thermoluminescent dosimeter (TLD),174

Thyroid probe, 91 Thyroid uptake, 92 Time and radiation protection, 171 Tomography, 124

computed tomography, 124 focal plane tomography, 124 PET, 131 SPECT,125 transverse, 124

Total effective dose equivalent, 168 Transient equilibrium in radioactive

decay, 30 Transition energy in radioactive decay,

14 Transport index, 182

Undifferentiated cells, 143 Uniformity of images, 117 Units, constants and, 186 Unrestricted area, 171 Uptake, thyroid, 92 Uranium-235, 43

Waste disposal, radioactive, 180 Wavelength of electromagnetic

radiation, 2 Wavelength shifter, 82 Weighting factor in radiation dose,

168 Well counter, gamma, 88

discrimination settings, 89 energy calibration of, 88 photopeak efficiency for, 91 sample volume effects, 89

Window setting, in pulse height analysis, 76

Wipe test, 177

X rays, characteristic, 6, 13 X, Y positioning circuit, 101

Yield, fluorescence, 14

Z-pulse in scintillation camera, 101