The function of a _______ is to reduce the scattered radiation produced in the patient before it reaches the X-ray film.

The function of a _______ is to reduce the scattered radiation produced in the patient before it reaches the X-ray film.

• A. Grid
• B. Filter
• C. Collimator
• D. Kevlar cassette

Answer: (A)

Scatter from the patient lowers image contrast, so placing a grid between the patient and the film helps. The grid is made of lead strips with radiolucent spacers, and it absorbs many of the scattered photons while allowing the primary beam to pass through the gaps. This selective absorption improves image contrast because fewer scattered photons reach the film. Keep in mind that because the grid also takes out some primary photons, you usually need to increase exposure to maintain film density.

Scatter from the patient lowers image contrast, so placing a grid between the patient and the film helps. The grid is made of lead strips with radiolucent spacers, and it absorbs many of the scattered photons while allowing the primary beam to pass through the gaps. This selective absorption improves image contrast because fewer scattered photons reach the film. Keep in mind that because the grid also takes out some primary photons, you usually need to increase exposure to maintain film density.