In CT, a ring artifact on the reconstructed image is most commonly caused by:

• A Patient motion during the scan
• B A miscalibrated or defective detector element ✓
• C Beam hardening from dense bone
• D Insufficient tube current (mAs)

Explanation

Ring artifacts arise from a faulty or miscalibrated detector channel that consistently reads incorrect attenuation values. As the tube rotates, this detector traces a ring centered on the isocenter. Patient motion causes blurring or streaking, beam hardening causes dark bands between dense objects, and low mAs causes quantum mottle (grainy noise), not rings.

Reference: Bushberg, The Essential Physics of Medical Imaging, 3rd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.