Safety Registry Review

Question 1

Ionizing radiation

Answer 1

radiation that possess the ability to remove electrons from atoms by a process called ionization

Question 2

Somatic effects

Answer 2

effects of radiation on the body being irradiated

Question 3

Genetic effects

Answer 3

effects of radiation on the genetic code of a cell; affects the next generation

Question 4

Natural background radiation

Answer 4

radiation contained in the unpolluted environment

Question 5

Artificially produced radiation

Answer 5

also called man-made radiation (e.g., medical x-rays)

Question 6

Primary radiation

Answer 6

radiation exiting the tube

Question 7

Exit radiation (remnant radiation; image producing radiation)

Answer 7

x-rays that emerge from the patient and strike the image receptor

Question 8

Attenuation

Answer 8

absorption and scatter (loss of intensity) of the x-ray beam as it passes through the patient

Question 9

Heterogeneous beam

Answer 9

x-ray beam that contains photons of many different energies

Question 10

Photoelectric effect

Answer 10

absorption of x-ray photons in the atoms of the body

Question 11

Compton effect

Answer 11

scatter of x-ray photons from the atom of the body

Question 12

Air kerma

Answer 12

unit of exposure

Question 13

Gray

Answer 13

unit of absorbed dose, measured in joules per kilogram (j/kg); 1 Gy = 1 J/kg

Question 14

Gray(a)

Answer 14

unit of radiation absorbed in air

Question 15

Gray (t)

Answer 15

unit of radiation absorbed in tissue

Question 16

Sievert

Answer 16

unit of effective dose

Question 17

Sievert

Answer 17

unit of equivalent dose

Question 18

Becquerel

Answer 18

unit of activity

Question 19

National academy of sciences/national research council committee on the biological effects of ionizing radiation (NAS/NRC-BEIR)

Answer 19

organization that studies biological effects of ionizing radiation and publishes resulting data

Question 20

International commission on radiologic protection

Answer 20

organization that publishes international radiation protection guidelines

Question 21

National council on radiation protection and management (NCRP)

Answer 21

organization that publishes radiation protection guidelines for the United States

Question 22

Nuclear regulatory commission (NRC)

Answer 22

organization that enforces radiation protection standards at the federal level related to use of radioactive material

Question 23

NCRP Report #102

Answer 23

makes recommendations on equipment design and protection regarding lead shielding and fluoroscopic and mobile exposure rates

Question 24

NCRP Report #116

Answer 24

defines annual exposure limits; makes recommendations pertaining to risk-benefit analysis of radiation exposure; states that somatic and genetic effects should be kept to a minimum when radiation is used for diagnostic imaging

Question 25

Effective dose limit

Answer 25

upper boundary dose that can be absorbed, either in a single exposure or annually, with a negligible risk of somatic or genetic damage to the individual; effective dose implies whole-body radiation exposure

Question 26

Cumulative effective dose

Answer 26

lifetime occupational exposure must not exceed the radiographer's age multiplied by 10 mSv

Question 27

Equivalent dose

Answer 27

equal to the effective dose multiplied by the radiation weighting factor

Question 28

As low as reasonably achievable (ALARA)

Answer 28

concept of radiologic practice that encourages radiation users to adopt measures that keep the dose to the patient and themselves at minimum levels

Question 29

Dose-response curves

Answer 29

graphs that illustrate the relationship between radiation dose and the response of the organism to exposure; may be linear or nonlinear, threshold or nonthreshold

Question 30

Probablistic (stochastic) effects

Answer 30

randomly occurring effects of radiation; the probability of such effects is proportional to the dose (increased dose equals increased probability, not severity, of effects)

Question 31

Deterministic effects

Answer 31

effects of radiation that become more severe at high level of radiation exposure and do not occur below a certain threshold dose

Question 32

Genetically significant dose (GSD)

Answer 32

average annual gonadal dose of radiation to individuals of childbearing age; addresses the relationship of gonadal doses to individuals versus an entire population and the overall effects

Question 33

Linear energy transfer (LET)

Answer 33

amount of energy deposited by radiation per unit length of tissue

Question 34

Relative biological effectiveness (RBE)

Answer 34

ability to produce biological damage; varies with the LET

Question 35

Direct effect

Answer 35

effect that occurs when radiation directly strikes DNA in the cellular nucleus

Question 36

Indirect effect

Answer 36

effect that occurs when radiation strikes the water molecules in the cytoplasm of the cell

Question 37

Radiolysis of water

Answer 37

effect that occurs as radiation energy is deposited in the water of the cell: a positively charged water molecule (HOH+) and a free electron

Question 38

Mutation

Answer 38

erroneous information passed to subsequent generations via cell division

Question 39

Law of Bergonie and Tribondeau

Answer 39

cells are most sensitive to radiation when they are immature, undifferentiated, and rapidly dividing

Question 40

Early somatic effects of radiation

Answer 40

hematopoietic syndrome; gastrointestinal syndrome; central nervous system syndrome

Question 41

Late somatic effects of radiation

Answer 41

carcinogenesis; cataractogenesis; embryologic effects; thyroid dysfunction; life span shortening

Question 42

Cardinal principles of radiation protection

Answer 42

distance, time, shielding

Question 43

Distance

Answer 43

best protection against radiation exposure

Question 44

Personnel monitoring devices

Answer 44

optically stimulated luminescence (OSL) badge, film badge, thermoluminescent dosimeter (TLD)

Question 45

Mean marrow dose

Answer 45

average dose of radiation to the bone marrow