Where must persons present during exposure be located?

• A. Behind a shield allowing a view of the patient and the Exposure on indicator; wear protective apron or be at least 2 m from the source of scattered radiation (the patient’s head) and not in line with the primary beam.
• B. In front of the patient.
• C. In a separate room far from the equipment.
• D. In the hallway near the operator.

Answer: (A)

The main idea is protecting anyone present by using shielding and keeping a safe distance from the source of scatter. During exposure, the person should stay behind a protective barrier that still lets you see the patient and the exposure indicator. You should also wear a protective apron (and a thyroid collar if available). If a barrier isn’t available, you must be at least about two meters away from the patient’s head, which is where most scatter comes from, and you should not be in the path of the primary beam.

This combination reduces radiation exposure by both blocking direct radiation with shielding and reducing dose through greater distance (the inverse square law). Being behind shielding allows supervision of the patient and timing of the exposure without being in the beam path.

Choosing to stand in front of the patient, in a separate room far away, or in the hallway near the operator would place you in line with scatter or the primary beam or would make monitoring impractical, increasing exposure risk and not aligning with standard safety procedures.