An Unusual Stroke Mimicker: A Case of CT Artifact Produced by Contrast Leakage onto the Detector Panel.

To improve image quality and reduce the possibility of misdiagnosis, radiologists should be informed of both common and uncommon manifestations of artifact on computed tomography (CT) imaging. We present an unusual case of scanner-based artifact, which produced peripheral dark attenuation defects on several cranial CT exams obtained from a single scanner, mimicking cerebral infarction. After confirmation of the artifact with the use of a water-based phantom, the source was found to be from contrast material which had leaked onto the CT detector panel. The ability to recognize artifactual patterns and an understanding of quality control measures are crucial to identify and mitigate sources of artifact.