大鼠超急性脑缺血再灌注后缺血周围区CT灌注参数动态变化研究

目的:研究多层螺旋CT灌注成像在大鼠大脑中动脉栓塞及再灌注过程中缺血周围区CT灌注参数的动态变化与病理损伤机制之间的关系。方法:将52只SD大鼠随机分为假手术组(A组)、缺血2 h组(B组)和缺血6h组(C组),B组按缺血后再灌注时间分为0h、0.5h、1h、2h、4h、6h、24h组;C组也按缺血后再灌注时间分为0h、0.5h、1h、2h、24h组。每组各4只。各组动物于缺血后再灌注不同时间点行CTPI检查。扫描完成后立即处死大鼠行光、电镜检查。结果:A组脑血流灌注参数相对值及光、电镜结果均未见异常改变。B组随着再灌注时间的延长,rCBF、rCBV值逐渐上升,rMTT、rTTP值逐渐下降,再灌注后与A组比较无统计学意义(P0.05)。光镜显示B组缺血周围区神经元密度减小,部分细胞体积增大呈空泡变,部分神经元胞体及胞核浓缩。C组随着再灌注时间的延长rCBF仍维持在低水平。光镜显示C组R 24h见较多细胞胞浆嗜伊红染。电镜下B组缺血周围区毛细血管基底膜增厚但尚完整。C组缺血周围区胞浆电子密度轻度升高,线粒体嵴有断裂。结论:CT灌注成像在大鼠大脑中动脉栓塞及再灌注过程中的动态变化与病理损伤机制有一定相关性,缺血2h缺血周围区脑组织为可逆性损伤,缺血6h缺血周围区脑组织为不可逆性损伤。

Investigation of CT perfusion imaging after focal cerebral ischemia in rats of ischemia peripheral zone

Objective:To investigate the relationship between CT perfusion imaging and pathological changes in the right middle cerebral artery occlusion of rats in ischemia peripheral zone.Methods:All 52 rats were divided into 3 groups: Group A(sham-operated) was taken as control study);Group B(occluded for 2 hours),CTPI scan were performed at 0 h,0.5 h,1 h,2 h,4 h,6 h,24 h after reperfusion;Group C(occluded for 6 hours),CTPI scan were performed at 0 h,0.5 h,1 h,2 h,24 h after reperfusion.All rats were killed immediat...