DWI评价大鼠急性脑梗死模型制备的价值

目的 观察大鼠急性脑梗死模型的MR扩散加权成像(DWI)表现,探讨DWI和神经功能缺失评分判定线栓法制作急性脑梗死动物模型的可靠性.方法 将雄性SD大鼠随机分成3组,对照组(10只)、假手术组(10只)、脑梗死组(10只).脑梗死模型组用Longa线栓法制备大鼠脑梗死模型(大脑中动脉闭塞),假手术组手术方法同脑梗死模型组,仅将线栓插入颈内动脉内约1 min即拔出.两组分别于术后6 h行MR扫描.各组大鼠均于检查完后行断头取脑,将脑组织进行TTC染色和常规HE染色.结果 脑梗死模型组中,栓塞后6 h的神经功能缺失评分＞3.对照组、假手术组及脑梗死模型组中1只大鼠脑组织病理结果为正常,T1WI、T2WI及DWI均未见异常信号.脑梗死组8只DWI序列显示大鼠大脑右侧基底节区出现高信号.以病理结果为金标准,神经功能缺失评分判断脑梗死造模成功的敏感性为89.00%,特异性为100%;DWI表现判断脑梗死造模成功的敏感性为100%,特异性为100%.结论 DWI技术在显示急性期脑梗死的灵敏度方面较神经功能缺失评分优越,可以早期显示脑缺血部位、范围,为动物脑梗死造模提供直观的影像学信息.

DWI assessment of the acute cerebral infarction model in rats

Objective To investigate the DWI patterns following single side middle cerebral artery occlusion with intraluminal thread in rats, and to assess the value and the reliability of DWI as the inclusive criteria in the acute cerebral infarction model in rats. Methods A total of 30 SD rats were divided into 3 groups: control group, sham operation group and cerebral infarction group (each n=10). Rats in sham operation group also adopted Zea Longa' method, but the nylon thread inserted into internal carotid artery was pulled out within 1 min. Rats in sham operation group and cerebral infarction group were scaned with MR after 6 h, and all rats were killed after finishing MR examination. The cerebral infarction was detected by TTC and pathological examination. Results In cerebral infarction group, rats scored beyond 3 were evaluated by standard neural function deficient degree. All rats in control group, shamoperation group and cerebral infarction group were histopathologically normal, and no positive signal in T1WI, T2WI or DWI was detected. High signal of DWI was detected in right basal ganglia area in 8 rats of cerebral infarction group, and histopathological changes were found. The sensitivity and specificity of DWI for acute cerebral infarction were 100% and 100%, while of score in the neural functional deficits were 89.00% and 100%, respectively. Conclusion DWI has high sensitivity for the diagnosis of acute cerebral infarction, being able to depict the location, extent of cerebral ischemia and provide intuitive imagings information of cerebral infarction.