Vocabulary

Question 1

Ionizing Radiation

Answer 1

Radiation that possesses 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 germ cell; Affects the next generation

Question 4

Artificially produced radiation

Answer 4

Man-made radiation (e.g., medical x-rays)

Question 5

Primary Radiation

Answer 5

Radiation exciting the x-ray tube

Question 6

Exit Radiation

Answer 6

X-rays that emerge from the patient and strike the image receptor, AKA Remnant radiation; image producing radiation

Question 7

Attenuation

Answer 7

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

Question 8

Heterogeneous beam

Answer 8

x-ray beam that contains photons of many different energies

Question 9

Photoelectric effect

Answer 9

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

Question 10

Compton Effect

Answer 10

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

Question 11

Roentgen (R)

Answer 11

Traditional unit of in-air exposure

Question 12

Coulombs per Kilogram (C/kg)

Answer 12

SI unit of in-air exposure

Question 13

Rad

Answer 13

Traditional unit of absorbed dose

Question 14

Gray

Answer 14

SI unity of absorbed dose

Question 15

Rem

Answer 15

Traditional unit of equivalent dose and effective dose

Question 16

Sievert

Answer 16

SI unit of equivalent dose and effective dose

Question 17

Curie

Answer 17

Traditional unit of activity

Question 18

Becquerel

Answer 18

SI 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 biologic effects of ionizing radiation and publishes resulting data

Question 20

International Commission on Radiological Protection (ICRP)

Answer 20

Organization that publishes international radiation protection guideline

Question 21

National Council on Radiation Protection and Measurements (NCRP)

Answer 21

Organization that publishes radiation protection guidelines for the US

Question 22

Nuclear Regulatory Commission (NRC)

Answer 22

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

Question 23

Effective dose limit

Answer 23

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 24

Cumulative effective dose (CED)

Answer 24

Lifetime occupational exposure must not exceed the radiographer’s age multiplied by 1 rem

Question 25

Equivalent dose limit

Answer 25

Upper boundary dose that can be absorbed, either in a single exposure or annually, with a negligible risk of a deterministic effect

Question 26

As low as reasonably achievable (ALARA)

Answer 26

Concept of radiologic practice that encourages a radiation users to adopt measures that keep the dose to the patient and themselves at minimal levels

Question 27

Dose-Response curves

Answer 27

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 28

Probabilistic Effects

Answer 28

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 29

Deterministic Effects

Answer 29

Effects of radiation that becomes more severe at high levels of radiation exposure and do not occur below a certain threshold dose

Question 30

Genetically significant dose (GSD)

Answer 30

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

Question 31

Linear Energy Transfer (LET)

Answer 31

Amount of energy deposited by radiation per unit length of tissue

Question 32

Relative biologic effectiveness (RBE)

Answer 32

Ability to produce biological damage; varies with the LET

Question 33

Direct effect

Answer 33

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

Question 34

Indirect effect

Answer 34

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

Question 35

Radiolysis of water

Answer 35

Effect that occurs as radiation energy is deposited in the water of the cell; The result of radiolysis is an ion pair in the cell: a positively charged water molecule (HOH+) and a free electron

Question 36

Mutation

Answer 36

Erroneous information passed to subsequent generations via cell division

Question 37

Law of Bergonie and Tribondeau

Answer 37

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

Question 38

Early somatic effects of radiation

Answer 38

Hematopoietic syndrome; GI syndrome; central nervous system syndrome

Question 39

Late somatic effects of radiation

Answer 39

Carcinogenesis; Cataractogenesis; embryologic effects; thyroid disfunction; life span shortening

Question 40

Cardinal principles of radiation

Answer 40

Time, distance, and shielding

Question 41

Distance

Answer 41

Best protection against radiation exposure

Question 42

Personnel monitoring devices examples

Answer 42

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

Question 43

Mean marrow dose

Answer 43

Average dose of radiation to the bone marrow