CT微血管表面通透性参数在检测缺血性脑卒中出血性转化中的应用

目的探讨CT灌注(CT perfusion,CTP)成像获得的脑组织局部微血管表面通透性(permeability surface,PS)参数在预测急性缺血性脑卒中后出血性转化中的应用价值。方法回顾性分析发病3~8h内急性缺血性脑卒中患者的影像学资料,所有患者均进行CTP检查。根据随访CT或MRI影像判断有无发生出血性转化(hemorrhagic transforma-tion,HT),分为出血组(PSHT)及未出血组(PSNo-HT)。采用Mann-Whitney U检验比较PSHT及PSNo-HT两者相应临床及影像学参数之间的差异。采用受试者工作曲线(receiver operating characteristic,ROC)分析相对表面通透性(rPS)值预测HT的敏感度及特异性。结果 26例患者进行入院CTP检查的患者中11例发生HT。PSHT组与PSNo-HT组患者的rPS值之间差异有统计学意义(P<0.05),两组患者的年龄、发病时间、rCBV及rCBF的差异无统计学意义(P值均>0.05)。ROC分析显示:rPS阈值为5.81时,预测HT的敏感性及特异性分别为90.91%、87.50%。结论动态CTP成像获得的PS参数图能够判断哪些患者易发生HT,在指导急性缺血性脑卒中患者的临床治疗方面有较高的应用价值。

Application of Micro-vascular Permeability Surface for Predicting Hemorrhage Transformation after Acute Ischemic Stroke using CT Perfusion Imaging

Objective To evaluate application of micro-vascular permeability surface（PS） maps derived from computed tomography perfusion（CTP） in prediction hemorrhagic transformation（HT） after acute ischemic stroke.Methods The patients who presented with acute ischemic stroke between 3 and 8 hours after stroke symptom onset were retrospective clinical history and image angiogram.All patients underwent pre-hospital CTP examinations.According whether developed HT,the patients were divided into PSHT and PSNo-HT.The rPS value between PSHT and PSNo-HT,was compared by using an exact Wilcoxon paired-sample signed-rank test with an exact 2-sided.The procedure was repeated in blood pressure classification between PSHT and PSNo-HT.A receiver operating characteristic（ROC） curve was calculated for analyzing the rPS value in predicting the sensitivity and specificity for hemorrhage transformation.Results Twenty-two patients were evaluated by admission admission CTP examinations.11 patients developed HT.There was significantly difference in rPS between PSNo-HT and PSHT（P0.05）.There was no significantly difference in age, onset time,rCBF and rCBV between two groups（P0.05）.The mean area under the ROC curve was 0.94±0.05（95% CI： 0～1.0）.The rPS threshold of 5.81 had 91% sensitivity and 88% specificity for predicting HT.Conclusions Elevated permeability can be detectable in acute ischemic stroke by using dynamic CTP.The quantitative analysis of the rPS value can distinguish patients with acute ischemic stroke who are likely from those who are not likely to develop HT.The data suggested that the risk would be low for patients with rPS 5.81 and significantly higher for those with rPS 5.81.