【作者】 魏梦绮； 宦怡； 赵海涛； 彭勇； 杜渭清； 葛雅丽； 张劲松；

【Author】 WEI Meng - qi, HUAN Yi, ZHAO Hai - tao , PENG Yong, DU Wei - qing, GE Ya - li, ZHANG Jin - song (Department of Radiology, Xijing Hospital, Fourth Military Medical Univercity, Xi’ an, Shaanxi Province 710032, China

【机构】 第四军医大学西京医院放射科；

【摘要】 目的:利用功能磁共振及常规MRI对大鼠(MCAO)急性脑缺血模型的研究,探讨功能磁共振在脑缺血早期诊断中的价值。方法:建立大鼠急性脑缺血模型,选用42只雄性SD大鼠(280-320g),随机分为手术组(A1组,n=28)、假手术组(A2组,n=14)。单丝尼龙线置入颈内动脉,阻闭右侧大脑中动脉。于术后30min、1h、2h、3h、6h、12h及24小时行功能及常规磁共振扫描,对两组结果进行比较分析。同时用光镜检查,观察大脑缺血后细胞与组织学改变。以探讨功能磁共振所观察的形态学及代谢改变与组织学变化的关系。结果:(1)A1组于栓塞后30min均可在DWI上出现异常高信号,T2WI则在栓塞后约2h才有异常发现,病变范围小于同期DWI,且边界不清。(2)A1组于急性期病灶中心血流灌注严重减少:rCBV、rCBF均较健侧减少(P<0.05),MTT较健侧明显延长(P<0.05),缺血区To及Tpeak时间明显较正常脑组织长。结论:功能磁共振对急性脑缺血的诊断更早期、快速、准确,并可获得相关的ADC值及血液动力学参数信息,能为急性脑缺血病理生理发展过程的动态研究提供帮助。更多还原

【Abstract】 Objective: Using fMRI and routine MRI on rat acute brain ischemia model to evaluate the value of fMRI to diagnose acute brain ischemia in the early phase. Methods: Establish the rat acute brain ischemia model with 42 male SD rats (280 - 320g) divided randomly into operation group (A1,n=28) and non - operation group (A2,n=14).Single strand of nylon was put into the right middle cerebral artery to obstruct it.30mins, 1h, 2h, 3h, 6h, 12h, 24h after operation routine MRI and fMRI examination were performed respectively on rat model and the results was compared. Microscopy was used to observe the cells and tissues’ change of brain. After that, the relationship between morphological, metabolic changes detected by fMRI and histological changes of brain tissue was discussed. Results: (1) In Al group, all rats showed high intense signal on DWI after ischemia was created for 30mins while 2h after that did they show abnormal signal in T2WI. The extent of the lesions in T2WI was smaller than that in DWI and the lesions in T2WI had obscure boundaries. (2) In Al group, the blood perfusion of the center area of the lesions in acute stage decreased seriously: rCBV, rCBF decreased (p < 0.05), MTT prolonged (p < 0.05) compared with the healthy hemisphere of the brain. The To and Tpeak prolonged compared with the time of normal brain tissue. Conclusion: fMRI can provide earlier, swifter and more accurate diagnosis of brain acute ischemia, and provide us the pertinent value of ADC and hemodynamics data , which is helpful for the study of pathophsiological development of the disease.更多还原