^18F－FDG microPET/CT在脑缺血再灌注模型筛选中的应用

Application of 18F-FDG microPET/CT in the screening of cerebral ischemia reperfusion models

目的探讨18F－脱氧葡萄糖（FDG） microPET/CT显像筛选脑缺血再灌注（CIR）模型的可行性。方法采用线栓法可逆性栓塞大脑中动脉制作大鼠CIR模型。术后清醒时，将Zea－Longa评分1～4分视为入选标准。共选取18只雄性SD大鼠。术后2和24 h，采用Garcia 18评分法进行大鼠神经功能评分。建模后2和24 h经尾静脉注射18F－FDG, 40 min后行microPET/CT显像，对图像进行视觉分析及半定量分析。对意外死亡的大鼠进行尸体解剖及HE染色；对术后24 h存活大鼠，在完成microPET/CT显像后取脑组织行氯化三苯基四氮唑（TTC）染色，观察脑梗死情况。以病理检查结果为＂金标准＂，采用Fisher确切概率法分析比较神经功能评分与microPET/CT评价CIR模型的准确性。结果18只入选大鼠的病理结果为：CIR模型11只，蛛网膜下腔出血（SAH） 4只，SAH伴脑出血3只。术后8～12 h，4只大鼠意外死亡。术后2 h，神经功能评分及microPET/CT的诊断准确性分别为11/18和15/18，差异有统计学意义（P〈0.05）；术后24 h，神经功能评分及microPET/CT的诊断准确性分别为11/14和14/14，差异无统计学意义（P〉0.05）。结论18F－FDG microPET/CT可比神经功能评分更早地筛选出CIR模型。

ObjectiveTo investigate the feasibility of 18F-fluorodeoxyglucose （FDG） microPET/CT in the screening of cerebral ischemia reperfusion （CIR） models.MethodsThe suture-occluded method was used to establish CIR rat models with reversible middle cerebral artery embolism. After that only awake rats whose Zea-Longa scores were 1-4 were selected for the following experiments, and 18 male SD rats were selected. Garcia scale with 18 points was used to evaluate the neurological function of rats at 2 and 24 h post-operation. At the same time points, 18F-FDG was injected into caudal vein after anesthesia and microPET/CT scan was conducted at 40 min post-injection. Visual and semi-quantitative analyses were adopted to analyze the images. The autopsy and HE staining were performed on accidentally dead rats. The other alive rats were sacrificed after microPET/CT scan at 24 h post-operation, and their brain tissues were taken out quickly to detect the infarction by triphenyl tetrazolium chloride （TTC） staining. The pathological results were taken as the gold criteria. Fisher exact test was used to compare the difference of accuracy for diagnosing CIR models between neurological function score （NFS） and microPET/CT.ResultsAccording to the pathology, there were 11 CIR models, 4 with subarachnoid hemorrhage （SAH）, 3 with SAH and cerebral hemorrhage. Between 8-12 h post-operation, 4 rats died accidentally. At 2 h post-operation, the diagnostic accuracies of NFS and microPET/CT were 11/18 and 15/18 （P〈0.05）. At 24 h post-operation, the diagnostic accuracies of NFS and microPET/CT were 11/14 and 14/14, respectively, no statistical difference was observed（P〉0.05）.Conclusion18F-FDG microPET/CT is better than NFS in screening CIR models in early stage.