CRA CRA Radiation Physics & Safety 2

Question 1

Which regulatory body is responsible for overseeing radiation safety in medical facilities using radioactive materials in the United States?

Accepted Answer

NRC (Nuclear Regulatory Commission)

Answer

The NRC regulates the civilian use of radioactive materials, including those used in nuclear medicine and radiation therapy.

Question 2

What is the purpose of collimation in diagnostic radiology?

Accepted Answer

To limit the X-ray beam to the area of clinical interest and reduce patient dose

Answer

Collimation restricts the X-ray beam to the area of interest, reducing unnecessary radiation exposure to the patient and improving image quality.

Question 3

Which type of radiation interaction with matter is most responsible for photoelectric effect in diagnostic radiology?

Accepted Answer

Low-energy photons interacting with inner-shell electrons

Answer

The photoelectric effect occurs when a low-energy photon is completely absorbed by and ejects an inner-shell electron from an atom.

Question 4

A lead apron used for radiation protection in diagnostic radiology typically provides an attenuation equivalent of:

Accepted Answer

0.5 mm Pb

Answer

Standard lead aprons used in diagnostic radiology are typically equivalent to 0.5 mm of lead, providing approximately 90% attenuation of scatter radiation.

Question 5

Radiation-induced health effects that have a threshold dose below which no harm occurs and increase in severity with dose are called:

Accepted Answer

Deterministic (non-stochastic) effects

Answer

Deterministic effects (e.g., radiation burns, cataracts) occur above a threshold dose and worsen in severity as dose increases.

CRA - Certified Radiology Administrator Practice Test

CRA - Certified Radiology Administrator Practice Test

CRA CRA Radiation Physics & Safety 2