Iconoscopic Evaluation of Cerebral Vascular Disease

Abstract

A major problem in patients with cerebral vascular disease has been correlating the neurological status with results from electroencephalography, carotid angiography, brain scanning and cerebral blood flow studies. The EEG is limited in regional localization when the involved area is small or if the adjacent collateral blood supply is sufficient. Blood vessels smaller than 0.5 mm in diameter cannot be visualized by carotid angiography because of resolution limitations. Unless there is anatomical alteration of the vascular bed, especially at the capillary level, the brain scan using 197 Hg or ^99mmTc pertechnetate will not show regions of increased radioactivity. Cerebral blood flow studies have been more precise in regional localization, especially when multiple collimated detectors and a tape recording system are used. However, inordinate time is required to retrieve and calculate these results. In contrast, iconoscopic study of the cerebral hemisphere [1, 2] has provided a rapid (1 min) procedure which has been used in 100 patients with clinical evidence of intracranial pathology. The radioisotope studies were performed following carotid angiography, using the same indwelling internal carotid artery catheter. 30 of these patients had cerebral vascular disease.