ARRT Radiation Protection Principles 3

Question 1

What does the acronym ALARA stand for in radiation protection?

Accepted Answer

As Low As Reasonably Achievable

Answer

ALARA stands for 'As Low As Reasonably Achievable' and is the guiding principle for minimizing radiation exposure.

Question 2

Which of the following exposure factors would result in the highest patient dose during a radiographic procedure?

Accepted Answer

Low kVp, high mAs

Answer

Low kVp increases photoelectric interactions and beam absorption, and high mAs increases the number of photons, together yielding the highest patient dose.

Question 3

Protective lead aprons used in fluoroscopy are typically equivalent to what lead thickness?

Accepted Answer

0.5 mm Pb

Answer

Standard lead aprons provide 0.5 mm Pb equivalency, attenuating approximately 90–95% of scatter radiation at fluoroscopic energies.

Question 4

Which of the following best describes stochastic radiation effects?

Accepted Answer

Effects whose probability increases with dose but have no threshold

Answer

Stochastic effects (e.g., cancer, genetic effects) have no established threshold; their probability increases with dose.

Question 5

During fluoroscopy, where should the radiographer stand to minimize scatter exposure?

Accepted Answer

At a 90-degree angle to the primary beam, at maximum distance

Answer

Standing at 90 degrees to the primary beam and maximizing distance reduces scatter dose by applying both angular and inverse-square-law benefits.

ARRT - American Registry of Radiologic Technologists Practice Test

ARRT - American Registry of Radiologic Technologists Practice Test

ARRT Radiation Protection Principles 3