Ring artifact

Ring artifacts are a CT phenomenon that occur due to miscalibration or failure of one or more detector elements in a CT scanner. Less often it can also be caused by insufficient radiation dose, or contrast material contamination of the detector cover 2. They occur close to the isocenter of the scan and are usually visible on multiple slices at the same location. They are a common problem in cranial CT.

The remedy is usually simple, recalibrate the scanner and let the referrer know that the worrying-looking ring shadows are artifactual. Occasionally detector elements need replacement which can be costly.

Physics and imaging technology: CT
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Article information

rID: 1988
Section: Physics
Synonyms or Alternate Spellings:
  • Ring artefacts
  • Ring artifacts
  • Ring artefact

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Cases and figures

  • Case 1: ring artefact
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  • Case 2: ring-artefact after reconstruction
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  • Case 3: streak, beam hardening and ring artifacts
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  • Case 4
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  • Case 5
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  • Case 6
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  • Case 7: partial ring
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  • Case 8
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  • Case 9
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