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

The primary purpose of using a grid in radiography is to improve image contrast. Grids are used to enhance the quality of the radiographic image by allowing only the primary rays that are directed at the image receptor to reach it while absorbing the scattered radiation that can degrade image quality. Scattered radiation occurs as X-rays interact with the tissues, and it can cause a fogging effect on the image, which reduces contrast and detail. By using a grid, radiographers can achieve a clearer image with better differentiation between structures, thus improving the diagnostic value of the radiograph.

While increasing image density can be a side effect of using a grid due to the increased amount of primary radiation that reaches the image receptor, the foremost objective remains the enhancement of contrast. The options related to reducing patient exposure and eliminating motion blur do not directly pertain to the primary role of a grid in enhancing image contrast. Grids are primarily deployed based on the density of tissue and the potential for scatter, rather than directly to minimize exposure or motion artifacts.