Radiation Protection Principles Flashcards

What does the acronym ALARA stand for in radiation protection?

Answer: As Low As Reasonably Achievable

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

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

Answer: Low kVp, high mAs

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

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

Answer: 0.5 mm Pb

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

Which of the following best describes stochastic radiation effects?

Answer: Effects whose probability increases with dose but have no threshold

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

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

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

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

What is the primary purpose of a secondary protective barrier in a radiographic room?

Answer: Shield against scatter and leakage radiation

Secondary barriers are designed to attenuate scatter and leakage radiation, which travel in all directions from the patient and tube housing.

A OSL dosimeter measures occupational radiation dose using which principle?

Answer: Stimulated luminescence from aluminum oxide crystals

Optically stimulated luminescence (OSL) dosimeters use aluminum oxide crystals that emit light proportional to absorbed dose when stimulated by laser light.