Contrast enhancement of cerebral infarcts. Incidence and clinical value in different states of cerebral infarction.

Information obtained from CT scan after contrast administration was evaluated in 59 consecutive stroke patients. CT scans before and after contrast administration were performed 3 days and 2 1/2 weeks after stroke. A plain CT scan was repeated 6 months later. Contrast enhancement was practically not seen on the first examination, but was seen in 46% on the second examination. There was a close relationship between the occurrence of contrast enhancement and the socalled "fogging effect". Contrast scanning gave additional information only when this effect was present. Plain CT scans 3 days after stroke were superior to contrast scans taken at any time for detecting and visualizing cerebral infarcts.