In calculating equivalent dose, which factor multiplies the absorbed dose?

In calculating equivalent dose, which factor multiplies the absorbed dose?

• A. Exposure rate
• B. Mass of tissue
• C. Tissue weighting factor
• D. Radiation weighting factor

Answer: (D)

Equivalent dose adjusts the energy deposited in tissue by the specific type of radiation, reflecting how biologically damaging it is. Start with the absorbed dose, which is the energy deposited per unit mass, and multiply it by a radiation weighting factor that represents the relative biological effectiveness of that radiation. This multiplier is what converts absorbed dose (Gy) to equivalent dose (Sv) because different radiation types cause different levels of harm even for the same energy deposition. The result is written as D × wR, giving an equivalent dose in sieverts. For example, alpha radiation has a much higher wR than gamma radiation, so the same absorbed dose from alpha particles yields a much larger equivalent dose. The exposure rate isn’t used in this conversion, the mass is already accounted for in the absorbed dose, and tissue weighting factors are used in a different concept (effective dose across tissues), not in determining the equivalent dose.

Equivalent dose adjusts the energy deposited in tissue by the specific type of radiation, reflecting how biologically damaging it is. Start with the absorbed dose, which is the energy deposited per unit mass, and multiply it by a radiation weighting factor that represents the relative biological effectiveness of that radiation. This multiplier is what converts absorbed dose (Gy) to equivalent dose (Sv) because different radiation types cause different levels of harm even for the same energy deposition. The result is written as D × wR, giving an equivalent dose in sieverts. For example, alpha radiation has a much higher wR than gamma radiation, so the same absorbed dose from alpha particles yields a much larger equivalent dose. The exposure rate isn’t used in this conversion, the mass is already accounted for in the absorbed dose, and tissue weighting factors are used in a different concept (effective dose across tissues), not in determining the equivalent dose.