Rad 260: Safety

Question 1

Exit radiation (image-producing radiation) are

Answer 1

X-rays that emerge from the patient and strike the image receptor; composed of primary and scattered photons

Question 2

Attenuation is

Answer 2

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

Question 3

Most common photon–tissue interactions in diagnostic radiography are______ and______ interactions.

Answer 3

Photoelectric and Compton

Question 4

Cardinal Principles of Radiation Protection

Answer 4

Time, distance, and shielding

Question 5

Fluoroscopy timer that sounds alarm after_______ of beam-on time.

Answer 5

5 minutes (300 seconds)

Question 6

Amount of filtration that reduces the intensity of the x-ray beam to half of its original value—measured at least annually by a qualified radiation physicist.

Answer 6

Half-value layer

Question 7

Main parts of the cell are the

Answer 7

Cell membrane, cytoplasm, and nucleus

Question 8

Early tissue reactions (deterministic) include:

Answer 8

1.Erythema
2.Epilation
3.Decreased blood count
4.Acute radiation syndrome

Question 9

Late tissue reactions (deterministic) include:

Answer 9

1.Cataractogenesis: Causes cataracts to form
2.Thyroid: cancer or cessation of function
3.Effect on fertility

Question 10

Stochastic effects (probabilistic) include:

Answer 10

1.Carcinogenesis: radiation-induced malignancy
2.Nonmalignant radiodermatitis
3.Embryologic effects: Most sensitive during the first trimester of gestation
4.Genetic mutations

Question 11

a.Indicates that no level of radiation can be considered completely safe
b.A response occurs at every dose
c.The degree of response to exposure is directly proportional to the amount of radiation received

Answer 11

Linear-nonthreshold relationship

Question 12

Linear-threshold relationship

Answer 12

a.Indicates that at lower doses of radiation exposure (to the left of the line intersecting the x-axis), no response is expected
b.When the threshold dose is exceeded, the response is directly proportional to the dose received

Question 12

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

Answer 12

Photoelectric effect

Question 13

a.Indicates that at lower doses of radiation exposure (to the left of the curve intersecting the x-axis), no response is expected
b.When the threshold dose is exceeded, the response is not directly proportional to the dose received and is increasingly effective per unit dose

Answer 13

Nonlinear-threshold relationship

Question 14

Nonlinear-nonthreshold relationship

Answer 14

a.Indicates that no level of radiation can be considered completely safe
b.A response occurs at every dose
c.The degree of the response is not directly proportional to the dose received
d.The effect is large even with a small increase in dose

Question 14

Photon-tissue interaction that produces radiation that may expose others in the room during fluoroscopy

Answer 14

Compton

Question 15

The unit of radiation absorbed in air is

Answer 15

Graya

Question 16

The unit of radioactivity is the

Answer 16

Becquerel

Question 17

Unit of effective dose and equivalent dose

Answer 17

Sievert

Question 17

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

Answer 17

Exit radiation

Question 18

Primary radiation

Answer 18

Radiation exiting the x-ray tube

Question 19

Ionizing radiation

Answer 19

Radiation that possesses the ability to remove electrons from atoms by a process called ionization

Question 20

Unit of equivalent dose is calculated as:

Answer 20

Sv = Gy × WR

Question 21

Unit of effective dose is calculated as:

Answer 21

Sv = Gy × WR × WT

Question 22

Meiosis

Answer 22

Describes the process of division of germ cells

Question 23

Erroneous information passed to subsequent generations via cell division

Answer 23

Mutation

Question 24

A ______ is placed in the x-ray beam to remove long-wavelength (low-energy) x-rays.

Answer 24

Filter

Question 25

Cosmic radiation:

Answer 25

Is a part of natural background exposure

Question 26

A feature of fluoroscopic x-ray machines that automatically adjusts kVp and mA to maintain image brightness for necessary image quality is called

Answer 26

Automatic brightness control (ABC)

Question 27

The total of air kerma over the exposed area of the patient is called:

Answer 27

Dose area product

Question 28

What agency publishes radiation protection standards based on scientific research?

Answer 28

National Council on Radiation Protection and Measurements (NCRP)

Question 29

The agency that enforces radiation protection standards relating to radioactive material at the federal level is the:

Answer 29

Nuclear Regulatory Commission (NRC)

Question 30

______occurs when radiation transfers its energy to DNA.

Answer 30

Direct effect

Question 31

_______states that each cell has a master molecule that directs all cellular activities and that, if inactivated, results in cellular death.

Answer 31

Target theory

Question 32

_______ is the amount of radiation required to increase the number of mutations in a population by a factor of 2.

Answer 32

Doubling dose

Question 33

Most of the damage to a cell occurs as a result of:

Answer 33

Indirect effect