An early CT sign of ischemic infarction: increased density in a cerebral artery.

The diagnosis of ischemic cerebral infarction by CT usually is not possible for 12-24 hr after the event. A sign that allows earlier diagnosis is increased density of a cerebral vessel secondary to a thrombus or embolus. We report 19 cases of increased density in a middle cerebral artery or one of its major branches visible on the initial CT scan of patients subsequently clinically proven to have suffered a cerebrovascular accident. In three cases angiography confirmed the presence of embolus or thrombus as seen on the CT scans. In several cases subsequent CT scans showed the density to dissipate, thereby confirming its nature as thrombus or embolus. Recognition of this finding will allow earlier diagnosis of ischemic infarction, which may be important in instituting an appropriate therapeutic regimen.