In calculating the entrance skin dose (ESD) for a technique using 60 mAs and an output intensity of 70 uGya/mAs, what is the resultant ESD?

To find the entrance skin dose (ESD), you multiply the output intensity by the technique used in terms of milliampere-seconds (mAs). In this case, the output intensity is 70 micrograys per milliampere-second (uGya/mAs), and the technique used is 60 mAs.

First, convert the output intensity from micrograys to milligrays since the final answer choices are in milligrays:

70 uGya = 0.070 mGya (since 1 mGya = 1,000 uGya).

Next, multiply this value by the mAs:

ESD = output intensity (in mGya/mAs) x mAs

ESD = 0.070 mGya/mAs x 60 mAs

ESD = 4.2 mGya.

Therefore, the resultant ESD is 4.2 mGya, which corresponds to the given choice. This calculated dose reflects the level of radiation exposure that a patient would receive at the entrance to the skin, allowing for safe and proper evaluations in radiologic practice.