Zarow G J, Graham S H, Mintorovitch J, Chen J, Yang G, Weinstein P R
Department of Neurological Surgery, School of Medicine, University of California, San Francisco, USA.
Neurol Res. 1995 Dec;17(6):449-54.
The purpose of this study was to ascertain if the signal intensity ratio and the lesion area determined by diffusion-weighted magnetic resonance imaging during brief focal ischemia and early reperfusion predict outcome determined by diffusion-weighted magnetic resonance imaging and T2-magnetic resonance imaging at 24 h. Seventeen rats were imaged before and during 30 min of endovascular middle cerebral artery occlusion and at 15 min, and 23.5 h after the onset of reperfusion. Both hemisphere and basal ganglia signal intensity ratio increased significantly from baseline during ischemia, decreased significantly from ischemic levels during early reperfusion, and increased again at 24 h. However, signal intensity ratio during ischemia or after 45 min of reperfusion did not correlate statistically with diffusion-weighted-signal intensity ratio at 24 h. Both hemisphere signal intensity ratio and basal ganglia signal intensity ratio at 15 min of reperfusion correlated, but only moderately, with diffusion-weighted-signal intensity ratio at 24 h (r = 0.52, p < or = 0.05). Although lesion areas during ischemia were comparable to those observed at 24 h, lesion areas at both 15 and 45 min of reperfusion were significantly smaller than those observed during ischemia and at 24 hr. Thus, sequential imagining demonstrated partial resolution and delayed recurrence of magnetic resonance-defined ischemic lesions during reperfusion after brief focal ischemia.
本研究的目的是确定短暂局灶性缺血和早期再灌注期间通过扩散加权磁共振成像测定的信号强度比和病变面积是否能预测24小时时通过扩散加权磁共振成像和T2加权磁共振成像测定的结果。对17只大鼠在血管内大脑中动脉闭塞30分钟前、期间以及再灌注开始后15分钟和23.5小时进行成像。在缺血期间，半球和基底节的信号强度比均较基线水平显著增加，在早期再灌注期间较缺血水平显著降低，并在24小时时再次升高。然而，缺血期间或再灌注45分钟后的信号强度比与24小时时的扩散加权信号强度比无统计学相关性。再灌注15分钟时的半球信号强度比和基底节信号强度比与24小时时的扩散加权信号强度比相关，但仅为中度相关（r = 0.52，p≤0.05）。尽管缺血期间的病变面积与24小时时观察到的相当，但再灌注15分钟和45分钟时的病变面积均显著小于缺血期间和24小时时观察到的。因此，连续成像显示短暂局灶性缺血后再灌注期间磁共振定义的缺血性病变部分消退并延迟复发。
