脑梗死大鼠脑水肿程度的磁共振DTI序列评估

Evaluation of cerebral edema in rats with cerebral infarction by magnetic resonance DTI sequence

目的:评估磁共振DTI序列评估脑梗死大鼠的脑水肿程度的价值。方法:将100只SD大鼠分为假手术组和MCAO模型组,每组50只。于MCAO后1、3、6、12、24 h对大鼠进行神经功能评分(mNSS)测定,并测量病灶侧的ADC值和FA值,采用免疫组化法测定脑组织中AQP-4蛋白的表达,每个时间点10只,并分析mNSS与ADC值、FA值及AQP-4表达的相关性。结果:与假手术组相比,MCAO模型组大鼠脑梗死区ADC值、FA值均降低,12 h降至最低,随后略有升高(P<0.05);mNSS和脑组织中AQP-4蛋白表达均增加(P<0.05)。MCAO模型组大鼠mNSS与ADC值及FA值呈负相关(r=-0.874、-0.856,P<0.05),与AQP-4蛋白表达呈正相关(r=0.885,P=0.013);FA值与ADC值呈正相关(r=0.848,P=0.004),与AQP-4蛋白表达呈负相关(r=-0.911,P=0.010);ADC值与AQP-4蛋白表达呈负相关(r=-0.798,P=0.005)。结论:磁共振DTI序列可动态监测脑梗死大鼠脑水肿程度。

Aim:To evaluate the cerebral edema in rats with cerebral infarction by magnetic resonance DTI sequence.Methods:A total of 100 SD rats were selected and randomly allocated into two groups(50 in each group),sham operation group and MCAO model group.The neurological function of rats was evaluated at 1,3,6,12 and 24 hours after MCAO(10 at each time point),and the ADC and FA values on the focal side were measured.The expression of AQP-4 protein in ischemic brain tissue was measured by immunohistochemical method.The relationship between neurological function score(mNSS)and ADC value,FA value,AQP-4 expression was analyzed.Results:Compared with the sham operation group,the values of ADC and FA in the cerebral infarction area of the MCAO model group decreased to the lowest at 12 hours,and then increased slightly(P<0.05).The expression of AQP-4 protein in the ischemic area and mNSS of the MCAO model group increased at different time points compared with the sham operation group(P<0.05).The mNSS of rats in MCAO model group was negatively correlated with ADC value and FA value(r=-0.874,-0.856,P<0.05),and positively correlated with AQP-4 protein expression(r=0.885,P=0.013),FA value was positively correlated with ADC value(r=0.848,P=0.004),and negatively correlated with AQP-4 protein expression(r=-0.911,P=0.010).ADC value was negatively correlated with AQP-4 protein expression(r=-0.798,P=0.005).Conclusion:DTI sequence could dynamically monitor the changes of cerebral edema in the cerebral infarction area of rats.