What is the primary purpose of using a grid in mammography?

In mammography, the primary purpose of using a grid is to improve image contrast by reducing scatter radiation. Scatter radiation occurs when x-rays interact with surrounding tissues and create additional, unwanted radiation that can degrade the quality of the image. This is particularly important in mammography, where clear visualization of subtle structures such as microcalcifications and small tumors is crucial for diagnosis.

The grid acts as a filter, allowing only the primary x-ray beams that travel in a straight line to reach the detector while absorbing some of the scattered radiation. This selective passage enhances the contrast of the image, making the details more discernible and allowing radiologists to identify abnormalities more effectively.

While the use of a grid may have some secondary effects, such as potentially leading to a more consistent exposure across the image, its main function in this context is focused on improving contrast due to the reduction of scatter.