Which statement best describes radiological dose metrics and their use?

Which statement best describes radiological dose metrics and their use?

• A. Gy is the absorbed dose; Sv and rem measure the effective dose
• B. Gy is the effective dose
• C. Sv is the absorbed dose
• D. Rem is unrelated to dose

Answer: (A)

The key idea is understanding what each unit means and what it measures in radiological dose. The gray measures absorbed dose—the actual energy deposited in tissue per kilogram. The sievert and the rem measure the effective (or dose equivalent) dose, which adjusts that energy by accounting for the type of radiation and the sensitivity of different tissues to produce a risk-related quantity. This is why the statement is best: it correctly assigns gray to absorbed dose and sievert/rem to effective dose. A rem is an older unit, with 1 sievert equals 100 rem, and 1 rem equals 0.01 sievert, reinforcing that both sv and rem relate to dose quality and biological risk rather than mere energy deposition.

The key idea is understanding what each unit means and what it measures in radiological dose. The gray measures absorbed dose—the actual energy deposited in tissue per kilogram. The sievert and the rem measure the effective (or dose equivalent) dose, which adjusts that energy by accounting for the type of radiation and the sensitivity of different tissues to produce a risk-related quantity. This is why the statement is best: it correctly assigns gray to absorbed dose and sievert/rem to effective dose. A rem is an older unit, with 1 sievert equals 100 rem, and 1 rem equals 0.01 sievert, reinforcing that both sv and rem relate to dose quality and biological risk rather than mere energy deposition.