A physiologic, mathematically derived method for interpreting first circulation time-indicator curves was used to evaluate 36 proven cases of cerebral pathology taken from the literature. The method of interpretation has been published previously and uses two physiologic parameters to assign each pair of time-indicator curves into one of nine possible categories. Each category is associated with a pathophysiologic state and a list of possible etiologies that were developed on theoretical grounds. Dynamic computed tomography was used in 25 cases and radionuclide angiography in 11; there were a variety of etiologies. Of the 36 cases, 26 (72%) fell in the predicted categories, three (8%) did not fall in the predicted categories, and seven (19%) had etiologies that were not considered in the theoretical classification. Thus, the actual patterns of time-indicator curves in the proven cases from the literature correlated reasonably well with the patterns previously predicted on theoretical grounds. The results give clinical support to this method of interpreting time-indicator curves.