Cerebral ischemia with CT.

One hundred fifty-eight patients with cerebral ischemia, and divided into four clinical groups were studied with CT. The results were correlated with those of angiography, scintigraphy and regional cerebral blood flow measurement. CT evolution was closely correlated with clinical and anatomical evolution. Changes in cerebral parenchyma density, in relation to the ischemic lesion, are the result of two phenomena: first, edema showing a fairly stable peak of intensity in the 2nd week and disappearing totally before the 20th day; and second, necrosis, variable in extent from patient to patient at the onset with subsequent evolution towards cavitation and thus a density similar to that of cerebro-spinal fluid.