磁共振弥散加权成像预测出血性转化实验研究

Value of DWI at 3.0T MRI in Predicting Hemorrhagic Transformation after Acute Ischemic Stroke in Rabbits

目的:探讨3.0T磁共振弥散加权成像(DWI)中表观弥散系数(ADC)值及指数表观弥散系数(e ADC)值对兔急性脑缺血性脑卒中出血性转化(HT)的预测价值。方法:37只新西兰大白兔颈内动脉注射自体血栓制备急性脑缺血性脑卒中模型,模型制备3.5h时行DWI检查,模型制备成功者,术后4h行尿激酶静脉溶栓。模型成功72h后处死动物,行HE染色。应用SPSS16.0统计学软件,采用独立样本t检验比较无HT组与HT组之间ADC值、e ADC值的差异有无统计学意义。结果:27只新西兰大白兔急性缺血性脑卒中模型制作成功,其中6例发展为HT,HI型5例,PH型1例。无HT组3.5h梗死区ADC值为(0.752±0.114)×10-3mm^2/s,HT组ADC值为(0.482±0.068)×10^(-3)mm^2/s,两组ADC值的差异有统计学意义(P=0.000)。无HT组3.5h梗死区e ADC值为0.479±0.053,HT组e ADC值为0.618±0.074,两组e ADC值的差异有统计学意义(P=0.000)。结论:缺血性脑卒中急性期ADC值、e ADC值的改变与HT的发生存在一定相关性,ADC值越低、eADC值越高则HT发生的可能性就越大,这对临床溶栓治疗的预后判断有一定的参考意义。

Purpose：To assess the value of apparent diffusion coefficient（ADC） and exponential apparent diffusion coefficient（e ADC） value of diffusion weighted imaging（DWI） in predicting hemorrhagic transformation（HT） after acute ischemic stroke in rabbits. Methods：Autologous thrombus was injected into unilateral internal carotid arteries of 37 New Zealand white rabbits to set up acute ischemic stroke model. These rabbits were undergone DWl on a 3.0T machine at 3.5 hours after operation. Thrombolytic therapies were carried out with urokinase at 4.0 hours after arterial occlusion. Rabbits were killed after the end of all scanning. Their brains were extracted and microscopic histological exams were done. The HT rabbits were classified into non-HT and HT group. The differences of ADC and e ADC between non-HT and HT group were assessed by using SPSS 16.0 software, P0.05 was considered to indicate statistical significance. Results：Acute ischemic stroke model was successfully set up in 27 rabbits. There were 6 rabbits who had HT included 5 rabbits with HI and 1 with PH. The ADC value of HT group was（0.482±0.068）×10^-3mm^2/s, the non-HT group was（0.752±0.114）×10^-3mm^2/s. There were statistical significant differences between non-HT and HT group in ADC values（P=0.000）. The e ADC value of HT group was 0.618±0.074, non-HT group was 0.479±0.053. There was statistical significance between non-HT and HT group in e ADC value（P=0.000）. Conclusion：There is correlation between the decrease of ADC, the increase of e ADC and the occurrence of HT in acute ischemic stroke.The changes of e ADC and EDC value can be used to predict HT, which may provide important information for thrombolysis therapy.