Which statement about equivalent dose is correct?

Which statement about equivalent dose is correct?

• A. It uses tissue weighting factors to convert absorbed dose to a tissue-specific dose
• B. It is the same as absorbed dose
• C. It is measured in Gray
• D. It applies only to occupational exposure

Answer: (A)

The concept being tested is how equivalent dose relates to the energy actually deposited in tissue and how its value reflects the potential biological effect of different radiation types. Absorbed dose tells you how much energy is deposited per unit mass (measured in Gy). To express this in a way that relates to risk for a specific tissue, that absorbed dose is weighted to account for how harmful the radiation is to that tissue, yielding a tissue-specific dose expressed in Sieverts. This weighting process is what makes equivalent dose different from the raw absorbed dose. The statement captured here describes that idea by noting the use of weighting factors to convert absorbed dose into a tissue-specific dose. In precise terms, the weighting factor used for the conversion is tied to the radiation type, and tissue weighting factors come into play when combining doses across tissues to get the overall effective dose. The other choices—being the same as absorbed dose, being measured in Gray, or applying only to occupational exposure—do not align with how equivalent dose is defined and used.

The concept being tested is how equivalent dose relates to the energy actually deposited in tissue and how its value reflects the potential biological effect of different radiation types. Absorbed dose tells you how much energy is deposited per unit mass (measured in Gy). To express this in a way that relates to risk for a specific tissue, that absorbed dose is weighted to account for how harmful the radiation is to that tissue, yielding a tissue-specific dose expressed in Sieverts. This weighting process is what makes equivalent dose different from the raw absorbed dose. The statement captured here describes that idea by noting the use of weighting factors to convert absorbed dose into a tissue-specific dose. In precise terms, the weighting factor used for the conversion is tied to the radiation type, and tissue weighting factors come into play when combining doses across tissues to get the overall effective dose. The other choices—being the same as absorbed dose, being measured in Gray, or applying only to occupational exposure—do not align with how equivalent dose is defined and used.