Question

Which of the following is a good estimate of the effective dose from a typical CT head scan?

1) .3 mSv
2) 2 mSv
3) 5 rem
4) 9 rem

Answer 1

A good estimate of the effective dose from a typical CT head scan is 2 mSv, as this aligns with the provided information that other X-ray procedures can range up to about 10 mSv in a CT scan.

Step-by-step explanation:

The question asks for an estimate of the effective dose from a typical CT head scan. Based on the provided information, which indicates that other X-ray procedures can range up to about 10 mSv in a CT scan, the best estimate from the given options for the effective dose from a typical CT head scan would be 2 mSv. It is important to note that 1 Sv is equivalent to 100 rem, therefore, options 3) 5 rem and 4) 9 rem are significantly lower than the approximate dose given by a CT scan, as they would convert to 0.05 and 0.09 mSv respectively, which are both much less than the 2 mSv estimate. Option 1) 0.3 mSv is also a low estimate compared to the typical doses ranging up to 10 mSv. Hence, the best estimate from the provided choices is option 2) 2 mSv.