Impact of computed tomography on utilization of cerebral angiograms.

In order to assess the effects of computed tomography (CT) of the brain on utilization of cerebral angiography, a retrospective analysis of three cohorts of patients was undertaken. Each cohort consisted of 50 consecutive patients receiving angiography either before a CT scanner was available, after installation of CT, or 1 year after CT. Since availability of CT, a progressive decrease in the proportion of angiograms that are normal has occurred (from 36% to 16%). Patients being evaluated for mass lesions account for the decrease. We conclude that CT is making neurodiagnostic evaluation more efficient and less invasive for patients with suspected mass lesions.