Which device shapes and limits the primary X-ray beam?

Which device shapes and limits the primary X-ray beam?

• A. Collimator
• B. Filter
• C. Anode
• D. Glass envelope

Answer: (A)

Shaping and limiting the primary X-ray beam is achieved by the collimator. The collimator sits at the tube head and uses adjustable lead shutters to define the field size and shape that reaches the patient. It often includes a light field that helps you align the X-ray beam with the image receptor, so you image only the area of interest. By constraining the beam, it reduces patient dose and decreases scatter radiation outside the intended area. The other components don’t shape the beam: a filter changes the energy spectrum by absorbing low-energy photons; the anode is the target where electrons produce X-rays; the glass envelope is just the tube housing.

Shaping and limiting the primary X-ray beam is achieved by the collimator. The collimator sits at the tube head and uses adjustable lead shutters to define the field size and shape that reaches the patient. It often includes a light field that helps you align the X-ray beam with the image receptor, so you image only the area of interest. By constraining the beam, it reduces patient dose and decreases scatter radiation outside the intended area. The other components don’t shape the beam: a filter changes the energy spectrum by absorbing low-energy photons; the anode is the target where electrons produce X-rays; the glass envelope is just the tube housing.