RAD 260: safety

Question 1

ionizing radiation

Answer 1

radiation that removes electrons by a process called ionization

Question 2

somatic effects

Answer 2

effects of radiation on the body being radiated

Question 3

genetic effects

Answer 3

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

Question 4

natural background radiation

Answer 4

radiation contained in the unpolluted environment

Question 5

artificially produced radiation

Answer 5

man-made radiation

Question 6

primary radiation

Answer 6

radiation exiting the x-ray tube

Question 7

exit radiation

Answer 7

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

Question 8

attenuation

Answer 8

absorption and scatter of the x-ray beam as it passes through the patient

Question 9

heterogenous 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 effeect

Answer 11

scatter of x-ray photons from the atoms in the body

Question 12

NCRP report 102

Answer 12

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

Question 13

NCRP report 116

Answer 13

defines annual exposure limits, makes recommendation 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 14

effective dose limit

Answer 14

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 15

cumulative effective dose

Answer 15

lifetime occupational exposure must not exceed the radiographers age times by 10 msv

Question 16

equivalent dose

Answer 16

equal to the effective dose times the radiation weighting factor

Question 17

dose response curves

Answer 17

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

Question 18

stochastic effects

Answer 18

randomly occurring effects of radiation the probability of such effects is proportional to the dose

Question 19

tissue reactions

Answer 19

effects of radiation that become more severe at high levels of radiation exposure and don’t occur below a certain threshold dose

Question 20

linear energy transfer (LET)

Answer 20

amount of energy deposited by radiation per unit length tissue

Question 21

relative biological effectiveness (RBE)

Answer 21

ability to produce biological damage; varies with the LET

Question 22

direct effeect

Answer 22

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

Question 23

indirect effect

Answer 23

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

Question 24

radiolysis of water

Answer 24

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

Question 25

mutation

Answer 25

erroneous information passed to the subsequent generations via cell divison

Question 26

law of bergonie and tribondeau

Answer 26

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

Question 27

early somatic effects of radiation

Answer 27

hematopoietic syndrome; gastrointestinal (GI) syndrome; central nervous system syndrome

Question 28

late somatic effects of radiation

Answer 28

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

Question 29

personnell monitoring devices

Answer 29

optically stimulated luminescence (OSL) badge, thermoluminescent dosimeter (TLD), digital ionization dosimeter

Question 30

mean marrow dose

Answer 30

average dose of radiation to the bone marrow

Question 31

National Academy of Sciences/National Research Council Committee on the Biological Effects of Ionizing Radiation (NAS/NRC-BEIR)

Answer 31

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

Question 32

International Commission on Radiologic Protection (ICRP)

Answer 32

organization that publishes international radiation protection guidelines

Question 33

National Council on Radiation Protection and Measurements (NCRP)

Answer 33

organization that publishes radiation protection guidelines for the United States

Question 34

Nuclear Regulatory Commission (NRC)

Answer 34

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

Question 35

air kerma

Answer 35

unit of exposure

Question 36

gray

Answer 36

unit of absorbed dose, measured in joules per kilogram (J/kg)

Question 37

sievert

Answer 37

unit of effective dose

Question 38

sievert

Answer 38

unit of equivalent dose

Question 39

becquerel

Answer 39

unit of activity

Question 40

Gray a

Answer 40

unit of radiation absorbed in air

Question 41

gray t

Answer 41

unit of radiation absorbed in tissue