In mobile X-ray examinations, the controlled area extends to how many metres from the X-ray source?

In mobile X-ray examinations, the controlled area extends to how many metres from the X-ray source?

• A. Two metres from the X-ray source
• B. One metre from the X-ray source
• C. Three metres from the X-ray source
• D. Five metres from the X-ray source

Answer: (A)

The main idea is about how radiological protection defines a restricted area around the X-ray source in mobile examinations. In these cases, the controlled area is set at a practical distance from the source to limit exposure to personnel not directly involved in the imaging. Two metres from the X-ray source is the standard boundary. This distance provides a safe buffer against the primary beam and the scattered radiation that results when a patient is imaged, while still allowing the procedure to be performed efficiently. The inverse square law means exposure falls off quickly with distance, so moving to a 2 m boundary keeps staff outside the most intense regions of radiation. Distances shorter than this would leave staff at higher risk from scatter, while much larger distances would complicate positioning and workflow without providing a meaningful safety gain in typical portable setups.

The main idea is about how radiological protection defines a restricted area around the X-ray source in mobile examinations. In these cases, the controlled area is set at a practical distance from the source to limit exposure to personnel not directly involved in the imaging.

Two metres from the X-ray source is the standard boundary. This distance provides a safe buffer against the primary beam and the scattered radiation that results when a patient is imaged, while still allowing the procedure to be performed efficiently. The inverse square law means exposure falls off quickly with distance, so moving to a 2 m boundary keeps staff outside the most intense regions of radiation. Distances shorter than this would leave staff at higher risk from scatter, while much larger distances would complicate positioning and workflow without providing a meaningful safety gain in typical portable setups.