What is the impact of using a grid with a higher grid ratio on image quality in radiography that requires a grid?

• A. Decreased image contrast
• B. No change in image contrast
• C. Increased image contrast
• D. Inconsistent image quality

Answer: (C)

Increasing the grid ratio makes the image more contrasty because it more effectively suppresses scattered radiation before it reaches the image receptor. Scatter adds a gray haze that washes out differences between tissues; taller lead strips and closer spacing in a higher-ratio grid absorb more of that scatter, so the primary beam’s differences are preserved, producing greater image contrast.

Keep in mind the trade-offs: you typically need more exposure to compensate for the grid's attenuation of the primary beam, and higher-ratio grids are more sensitive to alignment issues, which can cause grid cutoff if not centered correctly. But when a grid is used and the ratio is higher, the result is increased image contrast.