Cerebral contrast staining mimicking parenchymal haemorrhage in a stroke patient.

A 75-year-old female patient presented with signs and symptoms of a right hemispheric syndrome. A CT scan of the brain with angiogram showed an acute infarct in the right middle cerebral artery (MCA) territory secondary to thromb-occlusion of the M1 segment of the right MCA. A follow-up CT scan 2 weeks later showed a large hyperdense region in the infarcted area. With the aid of a dual-energy CT scan, this was eventually shown to be due to contrast staining from an earlier administration of iodinated contrast on the same day, rather than frank haemorrhagic conversion of the recent right MCA infarct.