弥散加权成像评价大鼠复苏后脑损伤研究

Diffusion-weighted Imaging to Evaluate the Brain Injury after Resuscitation in A Cardiac Arrest Rat Model

目的:对比分析不同时间点弥散加权成像(DWI)检查对评估大鼠心脏骤停(CA)模型心肺复苏(CPR)后脑水肿的价值。方法:将20只体重为(506±13)g的雄性SD大鼠随机分为sham组(n=6)、ROSC 6 h(n=7)组及ROSC24h组(n=7),利用气管插管制作大鼠心脏骤停窒息模型。模型组大鼠恢复自主循环(ROSC)6 h及24 h后行DWI序列扫描,假手术组于术后6 h扫描。对比分析各组大鼠全脑表观弥散系数(ADC值)及水通道蛋白4(AQP4)免疫组化结果的差异。结果:14只大鼠接受了CPR,12只大鼠成功ROSC其中2只未能ROSC,其余6只大鼠接受了假手术。ROSC6h组大鼠全脑ADC值明显低于sham组及ROSC 24 h组(P<0.05);sham组与ROSC24h组全脑ADC值无统计学差异(P>0.05)。ROSC6h组及ROSC24组大鼠神经细胞AQP4抗体表达均为阳性,ROSC6h染色强度明显高于ROSC 24 h组。结论:ADC值可用于CA/CPR后复苏早期(ROSC 6 h)脑水肿评估,但是在复苏后期(ROSC 24 h)评估脑水肿受限。

Objective:To explore comparative of the value of diffusion-weighted imaging(DWI)at different time points to evaluate brain edema after cardiopulmonary resuscitation(CPR)in a cardiac arrest(CA)rat model. Methods:Twenty male SD rats weighing(506±13)g were randomly divided into sham group(n=6),ROSC6 h group(n=7)and ROSC24 h group(n=7),and using a tracheal intubation to establish a rat asphyxia cardiac arrest model. The model groups were undergoing MRI scanning after recovered spontaneous circulation(ROSC)in 6 hours and 24 hours,and the sham group was performed MRI scanning at 6 hours after the operation. The differences of the whole brain apparent diffusion coefficient(ADC)value and immunohistochemical results of aquaporin 4(AQP4)among eachgroup were compared and analyzed. Results:Fourteen rats have received CPR,12 rats in the model group were successfully resuscitated,while two failed. The remaining six rats underwent sham-operation.The ADC value of the whole brain in the ROSC6 h group was significantly lower than that of the sham and ROSC 24 h groups(P<0.05). There was no significant difference in the ADC value of the whole brain between the sham and ROSC 24 h group(P>0.05). The expression of AQP4 antibody in ROSC6 h group and ROSC24 group were positive,and the staining intensity of ROSC6 h group was significantly higher than that in ROSC 24 h group. Conclusion:ADC value can be used to evaluate brain edema in the early stage of resuscitation(ROSC6 h)after CA/CPR,but there is limited in the late stage of resuscitation(ROSC 24 h).