Which statement about collimation and patient exposure is true?

Which statement about collimation and patient exposure is true?

• A. Collimation reduces patient exposure by limiting beam size
• B. Collimation increases patient exposure by focusing more radiation
• C. Collimation has no effect on exposure
• D. Collimation only affects image sharpness

Answer: (A)

Collimation shapes the X-ray beam to match the area of interest, so it irradiates less tissue. By restricting the beam size, you reduce the amount of tissue exposed and, as a result, the overall dose to the patient. Fewer tissues irradiated also means less scattered radiation within the body, which further lowers dose and can improve image contrast. This is why the statement is true: limiting beam size directly lowers patient exposure. Collimation does not increase exposure, nor does it have no effect, and while it can influence image quality, its primary impact is on dose reduction rather than sharpening alone.

Collimation shapes the X-ray beam to match the area of interest, so it irradiates less tissue. By restricting the beam size, you reduce the amount of tissue exposed and, as a result, the overall dose to the patient. Fewer tissues irradiated also means less scattered radiation within the body, which further lowers dose and can improve image contrast. This is why the statement is true: limiting beam size directly lowers patient exposure. Collimation does not increase exposure, nor does it have no effect, and while it can influence image quality, its primary impact is on dose reduction rather than sharpening alone.