Clinical significance ^<123>I-IMP single photon emission computed tomography in detecting regional cerebral blood flow

In order to estimate the N-isopropy- (I-123) p-Iodoamphetamine (^<123>I-IMP) single-photon-emission-computed tomography (SPECT) and cold Xenon CT, Cerebral blood flow (CBF) by means of both methods were measured almost simultaneously in 13 patients. The patients (10 males and 3 female) showed an age distribution from 33 to 69 years (mean＝57.4 years). Eleven patients had cerebral infarction and the other two patients had cerebral hemorrhage. All oatients have been at the choronic stage. ^<123>I-IMP was utilized for SPECT using a rotating gamma-camera system. The uptakes of ^<123>I-IMP were counted for 2030 min and again 3-4 hours after the injection. The CBF by Xe-CT was mesured by means of Xe gas inhalation method. The results were as follows : 1) In the correlation of L/R ratio between ^<123>I-IMP-SPECT and Xe-CT, the ratin of ^<123>I-IMP uptake count correlated to the CBF ratio in Xe-CT. 2) The diffuse low CBF areas may be well visualized by SPECT rather than by CT-scan. 3) CBF image of ^<123>I-IMP-SPECT could be useful to evaluate cerebro-vescular diseases. Moreover, it may provide some insights into the pathophysiology of cerebral remote effect and vaibility.