MISMATCH BETWEEN CEREBRAL BLOOD-VOLUME AND FLOW INDEX DURING TRANSIENT FOCAL ISCHEMIA STUDIED WITH MRI AND GD-BOPTA

We investigated the regional and temporal changes in cerebral blood vo lume (CBV), cerebral blood flow (CBF), and vascular transit time in se ven mongrel cats during 30 min transient focal ischemia, caused by occ lusion of the middle cerebral artery, Dynamic susceptibility contrast magnetic resonance imaging was done at 4.7 T, using fast gradient echo T-2 weighted imaging and intravenous injection of gadolinium-BOPTA/D imeglumine. During occlusion, the areas showing a blood volume change were predominantly within the middle cerebral artery territory and cou ld be divided into areas showing either CBV increases or decreases, Th e area with decreased blood volume also had decreased blood flow as me asured by our flow-based index (p < 0.05) and was located in the centr al territory of the middle cerebral artery, Peripheral to this region was an area showing increased blood volume but without significant CBF changes (p > 0.05), During reperfusion, the CBF increased in the enti re zone shoeing changes in blood volume during occlusion, and remained significantly elevated until 45 min postocclusion, while CBV remained elevated in the hyperemic rim for at least 2 h, The presence of a per i-ischemic zone showing flow/volume mismatch identified a region where in baseline CBF is maintained by means of compensatory vasodilatation, but where the ratio of CBF to CBV is decreased, Dynamic susceptibilit y contrast magnetic resonance imaging with gadolinium-BOPTA/Dimeglumin e may be a valuable technique for the investigation of regional and te mporal perturbations of hemodynamics during ischemia and reperfusion. (C) 1998 Elsevier Science Inc.