What is the approximate Entrance Skin Dose (ESD) for a patient during a fluoroscopic examination lasting 3 minutes, assuming an ESD of 40 mGyt/min?

To determine the approximate Entrance Skin Dose (ESD) during a fluoroscopic examination, you can calculate it by multiplying the ESD rate by the duration of the examination. In this case, the examination lasts 3 minutes with an ESD rate of 40 mGyt per minute.

The calculation would be:

Entrance Skin Dose = ESD rate × duration

= 40 mGyt/min × 3 min

= 120 mGyt.

This computation leads to an ESD of 120 mGyt, making the given answer correct. The rationale behind using this formula is rooted in understanding that the dose received by the patient's skin correlates directly with the time exposed to the fluoroscopic radiation at a given rate. This calculation is a standard approach used in radiology to assess patient exposure and ensure it remains within safe limits.