American Society of Radiologic Technologist (ASRT) Practice Exam

What technique helps to improve image quality when using digital imaging?

1. Higher kVp settings

2. Lower mAs settings

3. Increased grid ratio

4. Increased exposure time

The correct answer is: Increased grid ratio

Using an increased grid ratio significantly contributes to improving image quality when using digital imaging. Grids are designed to reduce the amount of scattered radiation that reaches the image receptor. When the grid ratio is increased, it better absorbs the scattered radiation while allowing more of the primary radiation to pass through. This leads to images with higher contrast and better detail, ultimately enhancing the diagnostic utility of the images produced. Higher kVp settings may lead to increased penetration of the beam, which can be beneficial in certain situations, but it does not directly improve image quality in terms of contrast in the same way that an increased grid ratio does. Lowering mAs settings, while sometimes necessary for reducing radiation exposure, can result in a decrease in the overall image quality by making the images too grainy or underexposed. Increased exposure time can also result in motion blur if the patient moves during the exposure, further degrading image quality rather than enhancing it. Therefore, the increased grid ratio stands out as the technique that specifically targets and mitigates the effects of scatter, thereby enhancing overall image clarity and contrast.