ARRT Radiation Physics and Radiobiology 4

Question 1

Which of the following is an example of deterministic (non-stochastic) radiation effect?

Accepted Answer

Cataracts from high-dose eye exposure

Answer

Cataracts are a deterministic effect with a dose threshold; they occur in all exposed individuals once the threshold is exceeded, with severity increasing with dose.

Question 2

Pair production requires a minimum photon energy of:

Accepted Answer

1.02 MeV

Answer

Pair production requires at least 1.02 MeV (twice the rest-mass energy of an electron, 2 × 0.511 MeV) to create an electron-positron pair.

Question 3

What does the term 'radiolysis of water' describe?

Accepted Answer

Ionization of water molecules by radiation producing free radicals

Answer

Radiolysis of water is the decomposition of water molecules by ionizing radiation, producing reactive free radicals such as hydroxyl (·OH) and hydrogen (H·) radicals.

Question 4

The ALARA principle in radiation protection stands for:

Accepted Answer

As Low As Reasonably Achievable

Answer

ALARA (As Low As Reasonably Achievable) is the guiding principle requiring radiation doses to be kept as low as possible while still achieving the diagnostic or therapeutic objective.

Question 5

Which type of chromosome aberration results from two simultaneous double-strand breaks in different chromosomes?

Accepted Answer

Translocation

Answer

Translocation results when double-strand breaks occur in two different chromosomes and the fragments rejoin incorrectly, exchanging segments between chromosomes.

ARRT - American Registry of Radiologic Technologists Practice Test

ARRT - American Registry of Radiologic Technologists Practice Test

ARRT Radiation Physics and Radiobiology 4