CAMRT Radiography Practice Exam

What happens to exposure factors as grid ratio increases?

1. They must be decreased

2. They remain the same

3. They must be increased

4. They become irrelevant

The correct answer is: They must be increased

As the grid ratio increases, exposure factors must be increased to maintain optimal image quality. A higher grid ratio indicates that the grid is more efficient at reducing the amount of scattered radiation that reaches the image receptor. This is because a higher grid ratio has thinner interspaces and leads to increased absorption of scattered photons, which enhances image contrast. However, as more of the scattered radiation is absorbed, a compensatory increase in exposure factors—such as milliampere-seconds (mAs) or kVp—is necessary to ensure that sufficient primary radiation makes it to the receptor to properly expose the image. If exposure factors are not increased, the resulting images may appear underexposed or lack adequate density, leading to potential misinterpretation of the diagnostic data. It's important to understand that while the grid helps improve image quality by minimizing scatter, it also demands adjustments in exposure settings to achieve the desired diagnostic outcome. This relationship between grid ratio and exposure factors is a crucial concept in radiographic technique and practice.