Computed tomography of cerebral infarction: hemorrhagic, contrast enhancement, and time of appearance.

Large confluent petechial hemorrhages and/or hemorrhage within infarct may be seen on CT scan. Small petechial hemorrhages are not resolved by current equipment and techniques. Elevation of absorption values of an infarct following contrast media primarily occurs in the first month after onset, and may be occasionally confused with a tumor. Sequential CT changes in infarcts correlate well with established pathologic changes. Cerebral infarction may be seen on CT scan in some cases as early as 24--48 hr after its onset.