CT skin dose is typically on the order of which range?

CT skin dose is typically on the order of which range?

• A. 0.5 rad
• B. 1 rad
• C. Five rad
• D. Ten rad

Answer: (C)

CT skin dose reflects the amount of radiation deposited where the beam enters the patient. Because a CT scan uses a rotating gantry and a relatively wide beam, the entrance point on the skin tends to receive a higher dose than a single radiographic view. For a typical diagnostic CT exam, the entrance-skin dose is in the order of a few rad, commonly around five rad (about 50 mGy). This rough range accounts for differences in body region, technique, and scanner design, and while actual values vary, five rad is a good general estimate. Values like 0.5 or 1 rad are generally too low for standard CT, and ten rad would be higher than typical modern CT skin doses, though optimization and protocol choice can influence the exact amount.

CT skin dose reflects the amount of radiation deposited where the beam enters the patient. Because a CT scan uses a rotating gantry and a relatively wide beam, the entrance point on the skin tends to receive a higher dose than a single radiographic view. For a typical diagnostic CT exam, the entrance-skin dose is in the order of a few rad, commonly around five rad (about 50 mGy). This rough range accounts for differences in body region, technique, and scanner design, and while actual values vary, five rad is a good general estimate. Values like 0.5 or 1 rad are generally too low for standard CT, and ten rad would be higher than typical modern CT skin doses, though optimization and protocol choice can influence the exact amount.