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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

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

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

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