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

• A. One rad
• B. One to several rads
• C. Ten rads
• D. Hundred rads

Answer: (B)

CT skin dose is the energy deposited in the skin by the X-ray beam during a scan. For typical clinical protocols, this surface dose is on the order of tens of milligray, which corresponds to roughly one to several rads. The reason this range makes sense is that a CT examination uses a rotating beam and multiple projections, so energy is delivered along the beam path and accumulates at the skin entry point, but the overall surface dose tends to stay in that low- to mid-rad range. Modern practice emphasizes dose optimization, so routine scans generally fall within this neighborhood. Doses reaching ten rads or more are less common and usually would reflect high-dose protocols or specific circumstances, while hundreds of rads would indicate an unusually high exposure.