If detector uniformity fails QA, what artifact might appear on the image?

• A. Image Shows Nonuniform Brightness or Mottling Across the Field
• B. Image Contrast Improves
• C. No Effect on Image
• D. Noise Decreases

Answer: (A)

Detector uniformity is about how evenly the detector responds across its surface when the same X-ray exposure is applied. If uniformity fails, the image shows nonuniform brightness across the field, often described as mottling or patchy shading. This happens because different areas of the detector respond slightly differently due to aging, defects, or calibration drift, so some portions appear brighter or darker than others even though the exposure was uniform. The resulting pattern degrades image quality and can obscure or mimic anatomy if not corrected.

Such a defect would not improve image contrast—it would create uneven brightness instead of a cleaner, more uniform appearance. It’s also not correct that there would be no effect on the image, nor that noise would decrease; the failure introduces a fixed pattern variation rather than reducing noise.