Contrast enhancement in ischaemic lesions. I. Relationship to prognosis.

The contribution of post-enhancement CT scans to the diagnosis of acute cerebral infarction was studied in a consecutive series of infarcts. The timing, density and pattern of enhancement were also analysed for any possible prognostic information, and the incidence of factors of known prognostic significance was estimated on plain and contrast enhanced scans. Enhancement patterns of infarcts were variable and in those cases in which the plain CT diagnosis was equivocal the post-enhancement CT was not infrequently ambiguous also, and occasionally misleading. The outcome of infarcts that enhanced was significantly poorer than in those not showing enhancement, although no relationship between the timing, density or pattern of enhancement and prognosis could be shown. Consideration of the distribution of other factors known to adversely affect prognosis in the two groups does not adequately account for the difference between them suggesting that the contrast medium itself could be the cause of the poorer outcome. There are few positive indications for post-contrast scanning of suspected infarcts and the possible adverse effects of contrast medium should be considered prior to administration.