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Appendix A Units and Constants

Energy 1 electron (eV) = 1.602 x 10- 12 1 kiloelectron volt (keV) = 1.602 x 10-9 erg 1 million electron (Me V) = 1.602 X 10-6 erg 1 (J) = 10 7 1 (W) = 107 ergs/s = 1 J/s 1 = 1 x 10-2 J/kg = 100 ergs/g 1 (Gy) = 100 rad = 1 J/kg 1 (Sv) = 100 rem = 1 J/kg 1 horsepower (HP) = 746W 1 calorie (cal) = 4.184 J

Charge 1 electronic charge = 4.8 X 10-10 electrostatic unit = 1.6 x 10-19 C 1 (C) = 6.28 X 10 18 charges 1 (A) = 1 Cis Mass and Energy 1 unit (amu) = 1.66 X 10-24 g = 1/12 the atomic weight of 12C = 931 MeV 1 electron rest mass =0.511 MeV 1 proton rest mass = 938.78 MeV 1 neutron rest mass = 939.07 MeV 1 pound = 453.6 g

Length 1 micrometer, or micron Cum) = 10-6 m = 104 A 186 Appendix A. Units and Constants 187

1 nanometer (nm) = 10-9 m 1 angstrom (A) = 10-8 cm 1 fermi (F) = 10-13 cm 1 inch = 2.54cm Activity 1 (Ci) = 3.7 X 10 10 disintegrations per (dps) = 2.22 x 1012 disintegrations per (dpm) 1 millicurie (mCi) = 3.7 x 107 dps = 2.22 X 109 dpm 1 microcurie {J.lCi) = 3.7 x 104 dps = 2.22 X 106 dpm 1 (Bq) = 1 dps = 2.703 X 10- 11 Ci 1 kilobecquerel (kBq) = 103 dps = 2.703 X 10-8 Ci 1 megabecquerel (MBq) = 106 dps = 2.703 X 10-5 Ci 1 gigabecquerel (GBq) = 109 dps = 2.703 X 10-2 Ci 1 terabecquerel (TBq) = 10 12 dps = 27.03 Ci Constants A vogadro's number = 6.02 X 1023 atoms/g· atom = 6.02 x 1023 molecules/g· Planck's constant (h) = 6.625 x 10-27 erg· s/cycle Velocity oflight = 3 x 10 10 cm/sec IT = 3.1416 e = 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 180 0 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 co• efficient, J1.) or per of an absorber (mass attenuation coefficient, J1.m)· Auger electron. An electron ejected from an energy shell, instead of a charac• teristic 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 10 23• 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 parti• cles near the nucleus of an absorber atom. Carrier. A stable element that is added in detectable quantities to a radio• nuclide of the same element, usually to facilitate chemical processing of the . 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 sys• tem contributed by the collimator. It is also called geometric resolution.

Committed dose equivalent (H T •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 10 10 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/cm2 ) 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. . An instrument to measure the cumulative dose of radiation re• ceived during a period of . . 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 elimi• nation 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 half• lives, respectively. 190 Appendix B. Terms Used in Text

Electron (e-). A negatively charged particle rotating around the atomic nu• cleus. 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 emis• sion 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 un• paired electrons. Generator, radionuclide. A device in which a short-lived daughter is separated chemically and periodically from a long-lived parent adsorbed on adsor• bent 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 num• ber 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 com• bined 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 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 radioac• tive 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 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 K• shell 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 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-. 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 equi• valent in rem from rad. It is defined as the ratio of the amount of a stan• dard radiation that causes certain biological damage to the amount of radiation in question that causes the same biological damage. . The quantity of x- or y-radiations that produces one electrostatic unit of positive or negative charge in 1 cm 3 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. (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 radioactiv• ity 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/cm 2 ) 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. . 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 10 15 atoms (b) 0.24 pg 2. (a) 4.75 x 1014 dpm (b) 216 Ci or 7.99 x 10 12 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/cm2

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 Appendix C. Answers to Questions 195

Chapter 14

4. (a) 0.5 Rjhr (b) 6.96 mm Pb 6.1.77 mm Pb 7.10% Index

Aberration, chromosome, 142 Annual limit on intake (ALI), 168 Absorbed dose, 158-166, 167-171 Antineutrino, 14, 191 annual limit on intake (ALI), 168 Atom, 3 equivalent, 167, 189 binding energy of electron of, 5 deep-dose equivalent, 168, 189 composition of, 3 effective dose equivalent, 168 electronic structure of, 3-5 shallow-dose equivalent, 168, 192 structure of the nucleus of, 6 total effective dose equivalent, 168 Atomic mass unit, 1, 3 weighting factor, 168 Atomic number, 6 Absorbed fraction, 159 Attenuation of ,-radiations, 58-62 Absorber half value layer and, 61,190 half-value layer, 61 in PET, 132 linear attenuation coefficient of, 58 in SPECT, 129 linear energy transfer of radiations in, linear attenuation coefficient, 58 52 mass attenuation coefficient, 59 mass attenuation coefficient of, 59 tenth value layer and, 61 ranges of radiations in, 53 Auger electron, 13, 188 A bsorption of}' radiations, 58 Auger process, 13 Accidental coincidence in PET, 133 Autofluoroscope, 105 correction for, 134 Avalanche ionization, 66 Accuracy, 34, 188 A verage value, 34 Activity, 21 Avogadro's number, 24, 46,187 radioactivity, 21 units of, 26 Agreement states, 175 Backprojection in tomography, 125 ALARA, program, 176 Backscatter peak, 79 Alpha «(X) decay, 14 Backscattering of y rays, 57, 78 Aluminum breakthrough test, 49 Bar phantom, 111 Analog-to-digital converter (ADC), 104 Becquerel (Bq), 26 Anger scintillation camera, see Gamma Beta (fr) particle, 14 camera average energy of, 15 Annihilation radiations, 17, 55, 80, 188 decay, 14 coincidence detections in PET, 131 energy spectrum of, 15 escape peaks, 80 range of, 53 198 Index

Binding energy, 188 Chain reaction, nuclear, 42 nuclear, 7 Characteristic x rays, 6, 13, 19 of electron, 5 peaks, 79 Bioassay, 179 Charged particles Biologic half-life, 25, 188 interaction of, with matter, 51 Bismuth germanate (BGO) detectors, linear energy transfer (LET), 52 132 ranges, 53 Bit, 104 Chart of the nuclides, 8 Blur, III Chromosome aberration, 142 Bragg ionization peak, 52 Chromosome in cells, 138 Bremsstrahlung, 54 Coincidence circuit in liquid scintillation, 81 Coincidence detection lie (Carbon-II), 44, 132 accidental or random, 133 Cadmium-tellurium detector, 83 correction, in PET systems, 134 Calibration liquid , 81 dose calibrator, 69 Collimators, 95, 100 high voltage or energy, in well converging, 95,100 counter, 89 diverging, 100 , 72 efficiency of, 116 Carcinogenesis by radiation, 151-152 fan beam, 100, 110 risk of, 151 focal length of, 95 Carrier, 41 focal point, 95 Carrier-free, 41 focused, for rectilinear scanner, 95 Cataractogenesis, 153 for thyroid probe, 91 Caution signs and labels, 178 holes, 95, 100 Cell survival curve, 144-149 parallel hole, 100-101, 108-110 Do, 145 pinhole, 100

Dq ,145 resolution of, 108-111 effects of dose rate on, 146 septal thickness, 95, 108 effects of LET of radiations on, 147 Color quenching, 82 effects of radioprotectors on, 149 Committed dose equivalent, 167, 189 effects of radiosensitizers on, 147 Compton edge, 78 extrapolation number n, 146 Compton electron, 56 oxygen effect on, 147 Compton plateau, 78 Cells, 138-140 Compton scattering, 56 chromosome, 138 Compton valley, 78 composition of, 138 Computers cycle, 139 in digital scintigraphy, 104 cytoplasm, 138 in SPECT, 125 DNA synthesis, 140 Confidence level in statistics, 35 gene, 138 Constants and units, 186 meiosis, 139 Contrast, image, 119-120 mitosis, 139 film contrast and, 119 nucleus, 138 patient motion and, 120 survival curve, 144 scatter radiations and, 119 Center of rotation in SPECT, 129, Control rods, reactor, 42 135 Converging collimator, 95, 96, 100 Central nervous system death, 150 fan beam, 100, 110 Index 199

Conversion electron, see Internal intrinsic efficiency, 85 conversion photopeak efficiency or photofraction, Counting, statistics of, see Statistics of 86 counting Detectors Counting of radioactivity, 90 bismuth germanate (BGO), 132 differential, 76 cadmium-tellurium, 83 integral, 76 gas-filled, 65-72 Cross section in nuclear reaction, 45, 189 liquid scintillation, 73, 81 Cumulated activity in dosimetry, 161 NaI(TI), 73, 74, 99 Cumulative radiation dose, 160 of scintillation cameras, 99 Curie (Ci), 26, 187 semiconductor, 83 Cyclotron, 40-42 solid scintillation, 73 cyclotron-produced radionuclides, 40 Differentiated cells, 143 equation for production of Digital computer, 104 radionuclid.:!s,45 Digital image, 104 targets, 45 acquisition modes for, 104 matrix sizes in, 104 Dilution quenching, 82 Dead time, 87-88, 189 Direct action of radiation, 143 GM counters, 71, 87 Disintegration rate, 21 in nonparalyzable systems, 87 Display or storage, 76 in paralyzable systems, 87 for scintillation cameras, 103 losses, 87 Distance in radiation protection, 171 pulse pileup, 87 Diverging collimator, 100 scintillation cameras. 88 Dos and don'ts in radiation protection, Decay constant, 21, 189 175 Decay of radionuclides, 11-20 Dose alpha (l), 14 Calculation in , beta (Pl, 14-17 158 electron capture. 18-19. 190 calibrators, 68-70 equations, 21-23, 29-32 accuracy, 69 general, 21-23 constancy, 69 successive, 29-32 geometry, 69, 70 half-life, 23, 190 linearity, 69 isomeric transition (IT), 11-14, 190 quality control, 69 mean life, 25, 191 equivalent, 141 positron or P+, 17-18 limits, 170 schemes, 15 rate, 158 secular equilibrium, 31 effect of, on cell survival, 146 successive decay, 29-32 Dosimeter transient equilibrium, 30 pocket, 70 units of radioactivity, 26 thermoluminescent, 174 Decay scheme of radionuclide, 15 Dosimetry, internal radiation, see Deep-dose equivalent, 168, 189 Internal radiation dosimetry Delta rays, 51 Double break in chromosome, 142 Deoxyribonucleic acid, 138 Double escape peak, 80 Department of Transportation, 182 Doubling dose, see Genetic effects of Detection efficiency, 85, 86 radiation geometric efficiency, 86 Dynode of photomultiplier tube, 75 200 Index

EC, see Electron capture decay Fission, 43 Edge packing, 118 and radio nuclide production, 43 Effective dose equivalent, 168 Fluorescence yield, 14 Effective half-life, 25, 189 Focal-plane tomography, 124 Electromagnetic radiations, 2 Focused collimators for rectilinear , 2 scanners, 95 wavelength,2 Forces, nuclear, 7 Electron capture (EC) decay, 18, 190 Fourier transform in computed Electron volt, 2 tomography, 129 Electronic collimation in PET, 132 Frame mode of data acquisition, Electronic structure of atom, 3 104 Electrons, 3-6, 190 Free radical, 143, 190 Auger, 13, 188 Frequency, 2 binding energies,S, 7, 188 of electromagnetic radiation, 2 conversion, 12 spatial, 114 Embryologic damage by radiation, 153 Full width at half maximum, 85, 113 Emission computed tomography, 124 PET,131-135 SPECT,125-131 67Ga (Gallium-67), 44,61,172 Energy, I 68Ga (Gallium-68), 44, 172 and mass units, 1 Gain, amplification, 75 calibration of well counter, 89 Gamma camera, 97 -105 transition (decay), 14 collimators, 100 Energy resolution, 84, 190 console, 98 Equilibrium, 30-32 contrast, 119 secular, 31 detector, 99 transient, 30 digital computer, 104 Equilibrium dose constant, 159, 162 display and recording system, 103 Errors, 34 head,98 random, 34 mobile, 99 systematic, 34 multicrystal, 105 Escape peak photomultiplier (PM) tube, 101 double, 80 pulse height analyzer (PHA), 103 iodine, 79 sensitivity, 116 single, 80 collimator efficiency, 116 Excitation of atoms, 6, 51 spatial resolution, 107 Excited states, 11 collimator, 108 Exponential decay, 23 evaluation of, III Exposure rate, in survey meter, 177 intrinsic, 107 Exposure rate constants, 171 scatter, 110 thin detector, 100 tomography with, 125 18F (Fluorine-I 8), 44, 132, 172 quality control tests, 120 Fetus, effects of radiation on, 153 uniformity in, 117 Film badge for personnel monitoring, X, Y-positioning circuit, 101 173 emission, 11 Film contrast, 119 Gas-filled detectors, 65-75 Filter, ramp, in computed tomography, Geiger-Miiller counter, 70 128 Geiger region, 66 Index 201

ionization chambers, 68 Image reconstruction, 125 Cutie pie survey meter, 68 IllIn (indium-Ill), 44 dose calibrator, 68 decay scheme of, 18 pocket dosimeter, 70 Indirect action of radiation, 143 , 66 Information density, 97 proportional region, 66 definition, 97 region of continuous discharge, 67 Interaction of radiations with matter, region of recombination, 65 51-62 region of saturation, 65 Internal conversion, 12, 190 Gastrointestinal death, 150 characteristic x ray, 6, 13, 19 Gaussian distribution, 35 conversion electron, 12 Geiger-M tiller (G M) counters, 70-72 in electron capture, 19 avalanche, 66 in isomeric transition, 12 counting efficiency, 71 Internal radiation dosimetry, 158- dead time, 71, 87 166 quenching in, 70 absorbed dose in SI units, 161 Generators, radionuclide, 47-49 absorbed fraction, 159 aluminum breakthrough, 49 cumulated activity, 161 99Mo_99mTc generator, 48 dose calculation, 158 molybdenum breakthrough, 49 dose rate, 158 Genetic effects of radiation, 154-156 equilibrium dose constant, 159 doubling dose, 154 mean absorbed dose, 161 genetically significant dose, 155 Intrinsic resolution of scintillation Geometric efficiency, 86 camera, 107, 190 in photopeak detectors, 86 Iodine escape peak, 79 in scintillation counter, 116 lon, 190 Germanium-lithium [Ge(Li)] detector, Ionization, 6, 51 83 by charged particles, 51 Gray (Gy), 140, 190 primary, 51 secondary, 51 specific, 52 3H (), 44,181 Ionization chambers, 68-70 Half-life, in , 23-25, Cutie Pie survey meter, 68 190 dose calibrator, 68-70 biologic, 25 pocket dosimeter, 70 definition, 23 Ionizing radiations, 51 effective, 25 Isobars, 8, 190 physical, 23 Isomeric transition, 11, 190 Half-value layer (HVL), 61,190 Isomers, 8,11,191 Hemopoietic death, 150 Isotones, 8, 191 Hine-Duley phantom, 112 Isotope selectors, 69, 103 Isotopes, 8, 191

1231 (iodine-l23), 44 1251 (iodine-125), 44 K absorption edges, 56 131 1 (iodine-131), 44 K shell, 3 decay scheme of, 16 K shell binding energies, 5 Image distortion by converging and K x-rays, 13 diverging collimators, 101 Kinetics of radioactive decay, 21-33 202 Index

Lead shielding, 79, 173 Medical cyclotrons, 41 x-ray peak, 79 Medical uses of radioactive materials, Licenses for use of radio nuclides, 175 177 general license, 175 Metastable states of nucleus, 191 specific license of broad scope, 176 99Mo_99mTc generators, 48 specific license oflimited scope, 176 aluminum breakthrough, 49 Life-shortening effect of radiation, 152 99Mo breakthrough, 49 Line of stability of nuclides, 7 Moderators in reactors, 42 Line spacing in rectilinear scanning, Modifying factor in radiation 97 protection, 141 Line spread function (LSF), 113 Modulation transfer function (MTF), spatial resolution and, 113 114 Linear amplifier, 75 Molybdenum-99, 43, 44, 48 Linear attenuation coefficient of decay scheme of, 16 absorber, 58 fission product, 43, 44 Linear energy transfer, 52, 191 Monitoring, personnel, 173 definition, 52 Multichannel analyzer (MCA), 76 effects of, in radiation, 147 Multicrystal camera, 105 Liquid scintillation counters, 81 Multiformat imaging, 103 applications of, 82 Multihole focused collimator in counting efficiency, 82 rectilinear scanning, 95, 96 primary solute, 81 Multiple radio nuclide counting, 24, quenching, 82 90 scintillator, 81 Mutations, 142 secondary solute, 82 and doubling dose, 154 solubilizer, 82 genetic, 154 solvent, 81 spontaneous, 154 wavelength shifter, 82 List mode data acquisition, 104 Lithium-drifted detectors, 83 13N (Nitrogen-B), 44, 132 Long-term effects of radiation, 150-156 NaI(Tl) detectors, 74 genetic effect, 154 in scintillation cameras, 99 somatic effect, 151 in thyroid probes, 91 Lower level discriminator in radiation in well counters, 88 detectors, 7 properties of, 74 NaI(Tl) well counters, 88 detection efficiency of, 91 Magic numbers, 6 effect of sample volume, 89 Major organogenesis, effects of energy calibration, 89 radiation, 153 shielding, 89 Mass and energy, 1 NCA, see No carrier added Mass attenuation coefficient, 59 Neutrino, 17, 191 Mass defect in nucleus, 8, 191 Neutron number, 6 Mass number, 6,191 Neutrons, 3, 6 Matrix in computers, 104 characteristics of, 3 Mean absorbed dose per cumulated fast, 42 activity, 161 interaction of, in matter, 62 Mean life of radio nuclide, 25,191 mass of, 3 Mean value, 35 thermal, 42, 192 Index 203

Neutron activation analysis, see Pair production, 57 Neutron capture reactions Parallel hole collimators, 100 Neutron capture reactions, 43 classification of, 109 No carrier added (NCA), 41, 191 in scintillation cameras, 100 Noise performance parameters of, 108 background in LS counting, 81 resolution, 108 effect of, on image contrast, 119 sensitivity, 116 in SPECT, 130 Paralyzable counting systems, 87 Nonparalyzable counting systems, 87 Parent-daughter decay, 29 Nonpenetrating radiations, 171 Particulate radiations, definition of, 1 NRC (Nuclear Regulatory Commission), Patient motion, 120 175 effects of, on image contrast, 120 Nuclear binding energy, 7 Penetrating radiations, 171 Nuclear chain reaction, 42 Persistence oscilloscope, 103 Nuclear fission, 42, 43 Personnel monitoring, 173 Nuclear forces, 7 PET systems, 131 Nuclear reactors, 42 Phantoms, 111-112 equation for production of bar, III radionuclides, 45 Hine-Duley, 112 principles of, 42 Photocathode of photomultiplier tubes, production of radionuclides in, 42 75 Nuclear Regulatory Commission, 175 Photodisintegration, 58 Nucleons, 3 Photoelectric effect, 55 Nucleus, 3, 6 Photofraction, 86 binding energy of, 7 Photomultiplier (PM) tubes, 75, 101 line of stability, 7 in LS counting, 81 liq uid drop model of, 6 in scintillation cameras, 101 metastable state of, 8 in scintillation counters, 75 notation for, 6 in thyroid probe, 91 radius of, 3 in well counters, 89 shell model of, 6 Photons, 2, 6 Nuclides, 8 annihilations, 18,55,80 chart of, 8 attenuation of, 58 definition of, 8 Compton scattering of, 56 definition of, 6 interactions of, 55 150 (Oxygen-15), 44, 132 pair production of, 57 Occupational dose limits, 170 photoelectric effect of, 57 Orbital electrons, 3-5 Photopeak, 77 Organ, critical, 191 efficiency, 86 Organ, target, 191 energy resolution of, 85 Oxygen-15, 44, 132 Pinhole collimator, 100 Oxygen effect, 147 Pixels, 104 Oxygen enhancement ratio, 147 Placards in transportation of radioactive material, 183 Planck's constant, 2, 187 32p (Phosphorus-32), 44,54, 173 Pocket dosimeter, 70 Packaging in transportation of Polaroid film, 103 radioactive material, 182 POPOP, in liquid scintillation, 82 204 Index

Positron emission tomography (PET), Quenching 131-135 in GM counters, 70 annihilation coincidence detection in, in liquid scintillation counting, 82 131 attenuation correction in, 132 detectors in, 132 R (roentgen), 140, 192 electronic collimation, 132 Rad, 140, 192 quality control tests, 135 Radiation(s) random coincidences, 133 absorption of, 58 sensitivity of, 135 effects ofradiation on man, 149-156 spatial resolution, 134 genetic, 154 (r), 17 somatic, 151 annihilation of, 18,55, 80 electromagnetic, 2 decay, 17 ionizing, 51 Preamplifiers, 75 monitoring of, exposure, 173 Precision, 34, 191 non penetrating, 171 Pregnancy particulate, 1 effects of radiation, 153 penetrating, 55, 171 radiation dose limits, 170 Radiation area, 168 lO- rule, 154 high radiation area, 168 Preimplantation stage, effects of very high radiation area, 168 radiation, 153 Radiation biology, 138-166 Prodromal stage, 149 Radiation detectors Propagation of errors, 37 cadmium-telluride, 83 Proportional counters, 66 detection efficiency of, NaI(TI), 85 Protons, 3 energy resolution of NaI(TI), 84 atomic number, 3 gas-filled, 65-72 properties of, 3 liquid scintillation, 81 Pulse height analyzers (PHA), 76, 103 NaI(Tl),74 discriminator settings, 76 semiconductor, 83 gamma cameras, 103 thyroid probe, 91 liquid scintillation counter, 81 well type, 88 multichannel,76 Radiation dose, see Internal radiation principles of operation of, 76 dosimetry single channel, 76 Radiation dose limits, 170 spectrum, 77 Radiation dosimetry, internal, see well counters, 89 Internal radiation dosimetry window settings, 76 Radiation effects in rectilinear scanners, 97 carcinogenesis, 151 in scintillation cameras, 103 cataractogenesis, 153 Pulse pileup, 87 cell survival curves, 144-146 central nervous system death, 150 chemicals, effects of, 147 Quality control tests chromosome aberration, 142 dose calibrators, 69 differentiated cells and, 143 scintillation cameras, 120 direct action, 143 SPECT and PET, 135 dose rate and, 146 Quality factor (QF), 141, 191 doubling dose, 154 Quantum number, 3-5 genetic effects, 154 Index 205

genetically significant dose, 155 survey for exposure rate, 177 gastrointestinal death, 150 survey meters, 177 hemopoietic death, 150 Radiation Safety Committee, 176 indirect action, 143 Radiation Safety Officer, 176 in utero, 153 Radiation units, 140 linear energy transfer and, 147 Radioactive decay long-term, 150 annihilation radiation in, 18 oxygen effect, 147 antineutrino in, 14 radioprotectors, 149 Auger electron, 13 radio sensitizers, 147 Auger process, 13 short-term, 149 by alpha particle (IX) emission, 14 spontaneous mutation, 154 by beta minus (fr) emission, 14 stage of cell cycle, 149 by electron capture (EC), 18 tissue sensitivities, 143 by positron Ur) emission, 17 undifferentiated cells and, 143 calculation related to, 27 Radiation protection, 167-175 characteristic x ray, 6, 13 activity, 173 conversion electron, 12 ALARA,I77 decay constant, 21 definition of terms, 167 decay equations, 21, 29 distance, 17 effective half-life, 25 dos and don'ts in, 175 exponential, 23 film badge, 173 fluorescence yield, 14 personnel monitoring, 173 half-life, 23 principles of, 171 internal conversion, 12 radiation dose limits, 170 isomeric transition, 11 shielding, 173 mean life, 25 sources of radiation exposure, 169 neutrino, 17 thermoluminescent , 174 of mixed radionuclide sample, 24 time, 171 secular equilibrium, 31 Radiation regulations, 175-183 specific activity, 26 agreement state, 175 successive decay, 29 ALARA,177 transient equilibrium, 30 Department of Transportation, 182 transition energy, 14 dose calibrator, 177 Radioactive decay equations, 21 high radiation area, 168 successive, 29 licenses, 175 Radioactive packages, receiving and general license, 175 monitoring, 179 specific license of broad scope, 176 Radioactive spill, 181 specific license of limited scope, disposal, 180-181 176 decay in storage, 180 medical uses of radionuclides, 177 incineration, 181 Nuclear Regulatory Commission release into sewerage system, 180 (NRC),175 transfer to authorized recipient, 181 radiation area, 168 Radioactivity radiation safety committee, 176 calculation related to, 27 radiation safety officer, 176 decay equations, 21 radioactive waste disposal, 180 definition, 21 record keeping, 182 successive decay equations, 29 survey for contamination, 177 units of, 26 206 Index

Radionuclide(s) Restitution, 142 cyclotron produced, 40 Restricted areas and unrestricted areas, decay of, 11 168 definition of, 8 Roentgen (R), 140, 192 medical uses of, 177 -82,44, 132 production of, 40 reactor produced, 42 Radionuclide generators, 47 S, mean absorbed dose, 161 99Mo_99mTc generator, 48 Saturation factor in production of Radioprotectors, 149 radionuclides, 46 Radiosensitivity of cells and tissues, 143 Scatter radiations Radiosensitizers, 147 Compton, 56 Ramp filter in computed tomography, effect of, on spatial resolution, 110 128 in PET, 133 Random coincidences in PET, 133 in SPECT, 130 Random errors, 34 Scatter resolution, 110 standard deviations and, 34 Scintillation camera, see Gamma camera Ranges of charged particles in absorber, Scintillation detectors, 73 53, 192 detection efficiency, 85 Reactors, nuclear, 42 energy resolution, 84 chain reaction, 42 for rectilinear scanner, 95 control rod, 42 for scintillation camera, 99 equation for production of for thyroid probe, 91 radionuclides, 45 for well counter, 88 fission, 42, 43 geometric efficiency, 87 moderators, 42 intrinsic efficiency, 85 neutron capture reaction, 43 intrinsic resolution, 107 reactor-produced radionuclides, 42 NaI(Tl) detectors, 74 targets, 45 photofraction, 86 Receiving of radioactive packages, 179 photopeak efficiency, 86 Reconstruction, image, 125 Scintillation solvents, liquid, 81 in SPECT and PET, 125 Secondary electrons, 51 Record keeping in NRC regulations, 182 Secular equilibrium in successive decay, Rectilinear scanners, 95-97 31 focused collimator, 95 Semiconductor detectors, 83 information density, 97 Sensitivity photorecording, 97 in PET, 135 principles of operation of, 96 in scintillation camera, 116 spatial resolution, III in SPECT, 131 Region of recombination in gas Septal penetration, 108 ionization, 65 Septal thickness, 108 Regulations, radiation, see Radiation Sewerage disposal of radioactive waste, regulations 180 Relative biological effectiveness, 141 Shallow dose equivalent, 168, 192 Rem (roentgen equivalent man), 141 Shell model of nucleus, 6 Resolution, energy, 84 Shielding in radiation protection, 173 Resolution, spatial, see Spatial Sievert (Sv), 141, 192 resolution Silicon detectors, 83 Index 207

Single break in chromosome, 142 single escape peak, 80 Single channel analyzer (SCA), 76 spectrum, 76 Single escape peak, 80 actual, 77 Single photon emission computed ideal, 77 tomography (SPECT), see Spontaneous discharge in gas SPECT ionization, 67 SI units Spontaneous mutations, 154 gray, 140, 190 Standard deviation, 34 radioactivity, 26 Statistics of counting, 34-39 rem, 141, 192 accuracy, 34 Sodium iodide detectors, see errors, 34 Scintillation detectors Gaussian distribution, 35 Sodium iodide well counter, 88 percent standard deviation, 36 Source organs, 158 precision, 34, 191 Sources of radiation exposure, 169 propagation of errors, 37 Spatial frequency, 114 standard deviation of count rate, 36 Spatial resolution, 107-116, 192 standard deviation of counts, 34 collimator resolution, 108 Straggling of range, 53 evaluation of, 111-116 Successive decay of radionuclides, 29 bar phantoms in, III Survey for contamination and exposure line spread function in, 113 rate, 177 modulation transfer function in, Survey meters, 177 114 Cutie pie, 68 intrinsic resolution, 107 Geiger-Muller, 70 limits of, in PET, 134 Survival curves, cell, see Cell survival limits of, in SPECT, 130 curve scatter resolution, 110 System Internationale (SI) unit Specific activity of radionuclide, 26, 192 becquerel, 26 Specific ionization, 52, 192 rad, 140 SPECT, 125-131 rem, 141 attenuation correction, 129 Systematic errors, 34 factors affecting, 129 principles of, 125 reconstruction of image, 125 Target in production of radionuclides, back projection, 125 45 sensitivity, 131 Target, organ, 191 spatial resolution, 130 -99m (99ffiTc), 44 Spectrometry, gamma ray, 76-80 characteristics of, 44 backscatter peak, 79 decay scheme of, 12 characteristic x ray, 79 exposure rate constant of, 172 coincidence or sum peak, 80 generator, 48 Compton edge, 78 half-value layer of Pb for, 61 Compton plateau, 78 Tenth value layer (TVL) of absorber, 61 Compton valley, 78 Terms used in the text, 188 double escape peak, 80 Thallium-201 e01Tl), 44 energy resolution, 84 exposure rate constant, 172 iodine escape peak, 79 half-value layer, 61 photopeak, 77 Thermal neutrons, 42, 192 208 Index

Thermoluminescent dosimeter Waste disposal, radioactive, 180 (TLD),174 Wavelength of electromagnetic Thyroid probe, 91 radiation, 2 Thyroid uptake, 92 Wavelength shifter, 82 Time and radiation protection, 171 Weighting factor in radiation dose, Tomography, 124 168 computed tomography, 124 Well counter, gamma, 88 focal plane tomography, 124 discrimination settings, 89 PET, 131 energy calibration of, 88 SPECT,125 photopeak efficiency for, 91 transverse, 124 sample volume effects, 89 Total effective dose equivalent, 168 Window setting, in pulse height analysis, Transient equilibrium in radioactive 76 decay, 30 Wipe test, 177 Transition energy in radioactive decay, 14 Transport index, 182 X rays, characteristic, 6, 13 X, Y positioning circuit, 101

Undifferentiated cells, 143 Uniformity of images, 117 Units, constants and, 186 Yield, fluorescence, 14 Unrestricted area, 171 Uptake, thyroid, 92 Uranium-235, 43 Z-pulse in scintillation camera, 101