急性血栓法大鼠脑缺血模型不同区域DWI和PWI的演变规律  

Evolution of DWI and PWI in acute thromboembolic stroke model in rat

作　　者：尤小芳[1] 赵俊功[1] 李明华[1] 李永东[1] 程英升[1] 

机构地区：[1]上海交通大学附属第六人民医院放射科,上海200233

出　　处：《中国医学影像技术》2008年第6期830-834,共5页Chinese Journal of Medical Imaging Technology

基　　金：国家自然科学资金(30470506)资助

摘　　要：目的探讨血栓法大鼠脑缺血模型不同区域DWI和PWI随时间变化的规律。方法对成功建立的30只SD大鼠血栓法脑缺血模型在不同时间段进行MRI扫描,分析rADC、rNEI、rTTM和rMSI的变化规律。结果缺血灶内不同部位均表现为rADC、rNEI、rMSI下降,rTTM延长,中心区较边缘区明显。中心区24h内rADC无明显变化,24h后逐渐上升,边缘区rADC于脑缺血后逐渐下降,10h达最低点74%,7d后逐渐恢复至对侧相应区域水平,中心区与边缘区在脑缺血0.5～4h、8～24h存在显著差异(P<0.05)。中心区和边缘区rNEI变化相仿,分别为17.83%和50.45%,随缺血时间逐渐上升,中心区和边缘区24h内不同时间均存在差异(P<0.05)。缺血后rTTM逐步缩短。缺血3h内rMSI呈下降改变,随后逐渐升高。不同时间缺血中心区与边缘区rTTM和rMSI均存在交叉重叠。结论动态观察血栓法脑缺血模型DWI及PWI演变规律,可以更好地了解脑缺血后不同区域的血流及病理生理改变,为溶栓治疗时间窗提供个体化信息。Objective To investigate the evolution of DWI and PWI after acute stroke at the center and margin of the cerebral infarction.Methods Male SD rats（n=30）were established to acute thromboembolic stroke model.MRI was performed at different time with the aim to explore the evolution of rADC,rNEI,rTTM and rMSI.Results The rADC at center and margin of the cerebral infarction both declined after occlusion,and the descent extent at center is significant compared with that at margin.There was no significant difference of rADC at the center within 24 hours after stroke onset,then it ascended gradually.rADC at margin descended in a slow fashion,reached minimum at 10 h,and resumed at 7 d.There was significant difference（P〈0.05）of rADC at center with that at margin in 24 h.The evolution of rNEI over time at center and margin of the cerebral infarction showed a significant difference（P〈0.05）,and shared the same curve diagram.rNEI grew in a slow fashion over time,started to increase quickly at 24 h.The evolution of rTTM over time at center and margin showed no significant difference（P〉0.05）,and decreased slowly.The evolution of rMSI at center and margin showed no significant difference（P〉0.05）,and shared the same curve diagram.Score of rMSI descended in 3 h,then ascended after that.Conclusion With observation on the evolution of DWI and PWI in thromboembolic stroke model,we can better understand the micro blood circulation and pathology in acute cerebral ischemia,which can provide a strong theoretical basis for evaluation of the therapeutic efficacy after pharmaceutical intervention or therapy.

关 键 词：急性脑缺血 弥散加权成像 灌注加权成像 

分 类 号：R-332[医药卫生] R445.2