磁敏感加权成像在大鼠缺血性卒中缺血半暗带中的预测价值研究

Predictive value of susceptibility weighted imaging for ischemic penumbra in rats with ischemic stroke

目的研究磁敏感加权成像(SWI)在大鼠缺血性卒中缺血半暗带中的预测价值.方法将30只SD大鼠参照改良Longa法制备脑动脉缺血再灌注模型.造模成功后,采用磁共振机器进行扫描,分别扫描其扩散加权成像(DWI)、SWI和磁共振灌注造影成像(PWI)序列,采用2,3,5-三苯基氯化四氮唑(TTC)法检测脑组织梗死面积;采用Person相关性分析SWI与PWI检测之间的相关性,采用Kappa一致性检验SWI检测缺血半暗带的准确率、灵敏度、特异性、阳性预测、阴性预测和Kappa值;采用受试者工作特征(ROC)曲线分析SWI对缺血半暗带的预测价值,曲线下面积(AUC)表示诊断的准确度.结果SWI与PWI的脑组织ASPECTS评分和DWI不匹配区域呈显著正相关关系(r=0.795,P=0.000;r=0.812,P=0.000);采用一致性分析,SWI诊断缺血半暗带的灵敏度为92.00%,特异度为100.00%,准确率为93.33%,阳性预测值为100.00%,阴性预测值为71.43%,Kappa值为0.793;ROC分析显示,SWI诊断大鼠缺血性卒中缺血半暗带的AUC为0.933.结论SWI对大鼠缺血性卒中的缺血半暗带具有较高的预测价值.

Objective To evaluate the predictive value of susceptibility weighted imaging(SWI)for ischemic penumbra in rats with ischemic stroke.Methods Thirty SD rats were used for modeling ofcerebral artery ischemia reperfusion via modified Longa method.After successful modeling,the rats underwentmagnetic resonanceexaminationfordiffusion-weighted imaging(DWI),SWI,and perfusion-weighted imaging(PWI)sequences.The 2,3 and 5-triphenyltetrazolium chloride(TTC)method was usedto detect the infarct size of brain tissues.The correlation between SWI and PWI was analyzed by Pearson correlation analysis.Kappa consistency test was performed to detect accuracy,sensitivity,specificity,positive predictive,negative predictive and Kappa values of SWI for detecting ischemic penumbra.The receiver operating characteristic(ROC)curve was generated to analyze predictive value of SWI for ischemic penumbra.The area under the curve(AUC)was calculated toevaluate the diagnosticaccuracy.Results The brain tissues ASPECTS scores of SWI and PWI were significantly positively correlated with DWI-unmatched areas(r=0.795,P=0.000.r=0.812,P=0.000).Kappaconsistency analysis showed that the accuracy,sensitivity,specificity,positive predictive,negative predictive and Kappa values of SWI for diagnosis of ischemic penumbra were 92.00%,100.00%,93.33%,100.00%,71.43% and 0.793,respectively.ROC analysis showed that AUC of SWI for diagnosis of ischemia penumbra inischemic stroke rats was 0.933.Conclusion Relatively high predictive value ispossible with SWI for ischemic penumbra in ischemic stroke rats.