What is the primary purpose of using grids in imaging?

The primary purpose of using grids in imaging is to improve image quality by reducing scatter. Grids are designed to allow only the primary radiation—which is the useful beam that contributes to the image—to reach the image receptor while effectively absorbing scattered radiation. Scatter occurs due to the interaction of X-rays with matter, such as the patient’s body tissues, and it can degrade the quality of an image by reducing contrast and clarity.

By minimizing the amount of scatter that reaches the detector, grids help to enhance the visibility of anatomical structures, thereby improving overall image quality. This is particularly important in fluoroscopic and radiographic imaging, where high contrast is necessary to detect subtle changes in tissue structure.

While increasing exposure time can sometimes lead to better image quality, it is not the primary function of a grid. Additionally, the intention of grids is not to reduce patient dose; in fact, using grids may require a higher dose due to increased exposure times or higher mAs needed to compensate for the attenuation of the primary beam. Grids also do not serve to increase field size; instead, they primarily address the issue of scatter to enhance image quality.