To restrict the x-ray beam in radiography means the same as to

• A. filter
• B. attenuate
• C. preserve
• D. collimate

Answer: (D)

Collimation is the control of the x-ray beam’s size and shape, achieved with lead shutters to define the field of interest. This restriction limits radiation to only the anatomy being imaged, which lowers patient dose and reduces scatter, improving image quality by concentrating photons where they’re needed. Filtering changes the beam’s energy spectrum by absorbing low-energy photons, not the field size. Attenuation describes the weakening of the beam as it passes through matter, not how the beam is geometrically restricted. So restricting the beam to the area of interest is best described by collimation.