How does an increase in grid ratio affect the amount of scatter radiation reaching the image receptor?

An increase in grid ratio effectively decreases the amount of scatter radiation that reaches the image receptor. Grids are devices placed between the patient and the image receptor, designed to absorb scattered photons that would otherwise contribute to image fog and reduce contrast.

The grid ratio refers to the height of the lead strips in the grid compared to the distance between them. A higher grid ratio means that the lead strips are taller and closer together, making it more efficient at absorbing scatter. As a result, when the grid ratio is increased, it allows fewer scattered photons to pass through to the image receptor while permitting more direct, useful radiation to reach it. This leads to improved image quality by enhancing contrast and detail.

In contrast, options suggesting that the amount of scatter radiation increases or remains unaffected overlook the primary function of grids, which is to reduce scatter. The choice that states it causes complete absorption of scatter is inaccurate because no grid can absorb all scatter; some will inevitably reach the detector.