When one ring malfunctions, the image will appear as which dropout band at a depth?

When one ring malfunctions, the image will appear as which dropout band at a depth?

• A. Vertical dropout band
• B. A dropout band at all depths
• C. Horizontal or side-to-side dropout band
• D. Circular dropout band

Answer: (D)

When a single ring in the detector array fails, the artifact that appears is a circular dropout band. The detectors are arranged in a circle around the bore, so a fault in one ring creates a consistent error along that circular path in the projection data. After reconstruction, that error shows up as a ring encircling the image center, appearing at a fixed radius in every cross‑section. It’s this circular geometry that distinguishes it from vertical, horizontal, or depth-spanning dropouts, which would arise from faults aligned with rows, columns, or broader detector issues.

When a single ring in the detector array fails, the artifact that appears is a circular dropout band. The detectors are arranged in a circle around the bore, so a fault in one ring creates a consistent error along that circular path in the projection data. After reconstruction, that error shows up as a ring encircling the image center, appearing at a fixed radius in every cross‑section. It’s this circular geometry that distinguishes it from vertical, horizontal, or depth-spanning dropouts, which would arise from faults aligned with rows, columns, or broader detector issues.