Deck 9: Basic Radiation Protection and Radiobiology

Question 1

The dose equivalent limits for radiation workers are based on the radiation received from what source(s)?

A)Background radiation
B)Medical and dental radiography
C)Occupational exposure
D)Radiation fallout

Answer 1

C
Because patients and workers exposed to radiation are at risk for biologic effects,limits must be set to ensure safe practice for both patients and radiation workers.Dose measurement for radiation workers is limited exclusively to occupational exposure.The annual whole-body effective dose limit for the occupational worker is 50 mSv (5 rem).

Question 2

Which of the following is a principle of the ALARA concept?

A)All diagnostic x-ray exposure is low energy and of little concern.
B)The radiographer should hold a standard number of patients per year as long as it is below the allowable limits.
C)X-ray doses can increase progressively to allowable limits on older patients.
D)The radiographer's occupational exposure should be kept as low as reasonably achievable.

Answer 2

D
The concept of ALARA-as low as reasonably achievable-is used to guide radiation protection practices when performing examinations.This principle applies to both patients and coworkers.

Question 3

In which of the following x-ray interactions with matter is the energy of the incident photon completely absorbed?

A)Compton scattering
B)Photoelectric absorption
C)Bremsstrahlung interactions
D)Characteristic interactions

Answer 3

B
Because complete energy absorption takes place in photoelectric interactions,this constitutes the greatest hazard to patients in diagnostic radiography.Compton scattering contributes most to radiation worker exposure,and Bremsstrahlung and characteristic interactions are not x-ray photon interactions.

Question 4

With regard to the ALARA principle,the responsibility of the radiographer is to

A)obtain high-quality radiographs in an efficient manner.
B)keep radiation exposures at the lowest levels possible.
C)assess image quality as a function of dose.
D)determine the risk-to-benefit relationship between ordered examinations and dose.

Question 5

Acute radiation syndrome manifests in four major stages.In what order do these stages occur?

A)Latent period,prodromal period,manifest stage,and recovery or death
B)Manifest stage,prodromal period,latent period,and recovery or death
C)Prodromal period,latent period,manifest stage,and recovery or death
D)Manifest stage,latent period,prodromal period,and recovery or death

Question 6

Which of the following personnel radiation monitors will provide a near-immediate reading of radiation exposure,if necessary?

A)TLD
B)Film badge
C)Lithium fluoride chips
D)Pocket dosimeter

Question 7

The law of Bergonie and Tribondeau states that cells are more radiosensitive if they are
1)highly mitotic.
2)undifferentiated.
3)mature cells.

A)1 only.
B)1 and 2 only.
C)2 and 3 only.
D)1,2,and 3.

Question 8

Protective devices such as lead aprons are intended to protect the user from _____ radiation.
1)scattered and secondary
2)primary
3)remnant
4)latent

A)1 only
B)1,2,and 4 only
C)1 and 3 only
D)1,3,and 4 only

Question 9

The radiation a person receives from the sun (cosmic radiation)is categorized as

A)natural background radiation.
B)human-made background radiation.
C)human-made radiation.
D)radioactivity.

Question 10

For a pregnant radiographer who declares her pregnancy to the employer,a second personnel monitoring device is provided.The purpose of this additional monitor is to ensure that the monthly equivalent dose to the embryo or fetus does not exceed _____ mSv (_____ rem).

A)0.5;0.05
B)10;1
C)5;0.5
D)50;5

Question 11

Nausea is principally associated with the

A)prodromal period.
B)latent period.
C)central nervous system syndrome.
D)doubling-dose period.

Question 12

When laser light stimulates the sensing material in an optically stimulated luminescence dosimeter (OSL),the

A)material luminesces in proportion to the amount of radiation exposure received.
B)aluminum oxide stores the laser energy.
C)lithium fluoride chip emits light.
D)film darkens proportionally to the amount of laser light.

Question 13

The material commonly used for shielding against radiation exposure in protective aprons and gloves is

A)lead.
B)aluminum.
C)copper.
D)tungsten.

Question 14

The radiographic beam should be collimated so that it is _____ the image receptor.

A)slightly larger than
B)no larger than
C)twice as large as
D)four times as large as

Question 15

The photon interaction that results in the highest patient exposure is _____ interactions.

A)bremsstrahlung
B)Compton
C)classical scattering
D)photoelectric

Question 16

The function of an x-ray beam filter in diagnostic radiology is to

A)permit only alpha rays to reach the patient's skin.
B)permit only beta particles to interact with the atoms of the patient's body.
C)decrease the x-radiation dose to the patient's skin and superficial tissue.
D)remove gamma radiation from the useful x-ray beam.

Question 17

A given dose of radiation generally has the greatest potential for damage in tissues that have

A)the most cells.
B)the largest cells.
C)more rapidly dividing cells.
D)cells with the lowest water content.

Question 18

If a technologist stands 2 m from an x-ray tube and receives an exposure rate of 4 mR/hr,the exposure rate would be _____ mR/hr if the person stands 4 m from the x-ray tube.

A)1
B)2
C)3
D)4

Question 19

Which action of ionizing radiation is most prevalent and most harmful to the human body?

A)Direct action
B)Indirect action
C)Hormesis
D)Mitotic apoptosis

Question 20

A woman who is 3 months' pregnant has been in a motor vehicle accident.The emergency department physician suspects there is injury to her cervical spine and thus feels justified in ordering an x-ray examination to aid in determining the extent of the patient's injury.Because the patient is pregnant,the radiographer should
1)select the lowest exposure factors that will produce a diagnostically useful radiograph.
2)adequately and precisely collimate the radiographic beam to include only the anatomic area of interest.
3)shield the patient's lower abdomen and pelvic region with a suitable protective contact shield.

A)1 only.
B)2 only.
C)3 only.
D)1,2,and 3.

Question 21

With regard to the annual whole-body effective dose limit for occupational personnel

A)the annual limit in 50 mSv (5 rem).
B)the allowable cumulative whole-body dose limit is much lower than that permitted in the 1970s.
C)the maximum accumulated whole-body effective dose is calculated using 1 rem multiplied by the person's age (1 rem ´ age in years).
D)all of the above are true.