How does an increased grid ratio affect image quality?

An increased grid ratio enhances image contrast by improving the grid's ability to absorb scattered radiation while allowing primary radiation to pass through. Grids are used in radiography to reduce the amount of scatter that reaches the image receptor, which can obscure detail and degrade image quality.

When the grid ratio is higher, the grid strips are positioned closer together and are taller compared to the interspace material. This design effectively targets more of the scatter and allows a greater proportion of the primary beam to reach the detector, resulting in cleaner, sharper images with improved contrast. Greater contrast in an image helps differentiate between structures that may otherwise appear similar in the presence of scatter, thus making important diagnostic features more visible.

The other options—such as decreasing image sharpness, having no effect on image quality, or reducing overall exposure time—do not accurately reflect the role and benefits of a higher grid ratio. A higher grid ratio specifically enhances contrast, which is vital in producing high-quality radiographic images.