Which practice reduces scatter radiation and dose by restricting the beam to the region of interest?

Which practice reduces scatter radiation and dose by restricting the beam to the region of interest?

• A. Collimation
• B. Increased milliampere seconds (mA)
• C. Increased distance
• D. Increased kilovolts peak (kVp)

Answer: (A)

Collimation is narrowing the x-ray beam to the area of interest. When the beam is restricted to a smaller region, fewer tissues are irradiated, so fewer photons interact to produce scatter. Less scatter means better image contrast and a lower overall dose to the patient. The other options don’t accomplish this targeted restriction: increasing mA increases the number of photons and raises dose (and scatter), increasing kVp changes photon energy and can increase scatter while degrading contrast, and increasing distance changes geometry but doesn’t specifically limit exposure to the ROI.

Collimation is narrowing the x-ray beam to the area of interest. When the beam is restricted to a smaller region, fewer tissues are irradiated, so fewer photons interact to produce scatter. Less scatter means better image contrast and a lower overall dose to the patient. The other options don’t accomplish this targeted restriction: increasing mA increases the number of photons and raises dose (and scatter), increasing kVp changes photon energy and can increase scatter while degrading contrast, and increasing distance changes geometry but doesn’t specifically limit exposure to the ROI.