What is the function of the radiographic grid?

• A. Absorb primary radiation
• B. Absorb remnant radiation
• C. Absorb scattered radiation
• D. Absorb low energy radiation before it reaches the patient

Answer: (C)

Grids are used to improve image contrast by removing unwanted scatter before it reaches the image receptor. When X-rays pass through the patient, some photons scatter in many directions. This scattered radiation adds a hazy exposure to the image and reduces contrast, making structures harder to distinguish. The grid, with its alternating lead strips and radiolucent spaces, absorbs a large portion of that scatter while allowing the primary beam to pass through with minimal attenuation. By cutting down on scatter, the resulting image has sharper details and better contrast.

Absorbing primary radiation would darken the image and require higher exposure, which grids are not designed to do. Absorbing remnant radiation isn’t the specific function—remnant radiation includes both transmitted primary and scatter that reach the detector, and the goal is to reduce the scatter component. Absorbing low energy radiation before it reaches the patient is accomplished by filtration, not a grid.