Hyperintense Acute Reperfusion Marker on FLAIR in Patient with Possible Contrast-Induced Encephalopathy Following Cerebral Angiography

Contrast-induced encephalopathy (CIE) is a rare complication of angiography and endovascular intervention following administration of iodinated intravenous contrast agents. Neuroimaging findings of CIE usually show cerebral edema, leptomeningeal enhancement, and parenchymal signal abnormality on fluid-attenuated inverse recovery (FLAIR). Hyperintense acute reperfusion marker (HARM) generally implies an enhancement of the subarachnoid cerebrospinal fluid space on brain FLAIR imaging in cases of acute ischemic stroke or hyperperfusion syndrome. We report a case of possible CIE following cerebral angiography, accompanied by HARM sign.