【摘要】 目的探讨基线CT灌注(computed tomography perfusion,CTP)对动脉瘤性蛛网膜下腔出血(aneurysmal subarachnoid hemorrage,SAH)延迟性缺血(delay cerebral ischemia,DCI)的预测作用。方法回顾性分析2011年8月至2012年9月54例动脉瘤性SAH患者基线和1周后CTP。计算优势出血侧与对侧各参数比值,即相对血容量(rCBV)、相对血流量(rCBF)、相对平均通过时间(rMTT),感兴趣区(ROI)选基底节为中心的两层大脑前动脉分布区(ACA区)、中动脉分布区(MCA区)、后动脉分布区(PCA区)、基底节区及前、后分水岭区。结合复查CTP、CT平扫及神经功能临床评估确定DCI组和无DCI组,对两组基线、复查CTP分别行两样本t检验;对DCI组两次CTP行配对t检验;基线rCBF分为≤0.75、0.75<rCBF<0.85、≥0.85组,用χ2检验分析组间DCI发生率差异,运用SPSS16.0软件,P<0.05为有统计学差异。运用MedCalc 9.6 2.0通过受试者工作特征曲线(ROC)确定预测DCI的理想基线rCBF、rMTT、rCBV值。结果 18例(18/54,33.3%)发生DCI,基线CTP比较,DCI组、无DCI组平均rCBF分别为0.78和1.01(t=6.63,P<0.01),rCBV分别为0.90和1.01(t=4.43,P<0.01),rMTT分别为1.24和0.96(t=5.29,P<0.01)。DCI组复查较基线rCBF减低(t=3.18,P<0.05)、rCBV减低(t=2.83,P<0.05)、rMTT无统计学差异(t=0.99,P=0.38)。不同基线rCBF水平DCI发生率有统计学差异(χ2=38.00,P<0.05)。ROC分析:理想基线rCBF为0.84,预测DCI的敏感性、特异性分别87.5%、90.62%,曲线下面积(AUC)为0.945(95%CI:0.824~0.992);rMTT为1.1,敏感性、特异性分别为75%、84.37%,AUC为0.844(95%CI:0.694~0.939);rCBV为0.94,敏感性、特异性分别为75%、71.87%,AUC为0.781(95%CI:0.622~0.896)。结论在基线期采用CTP可以对存在DCI高风险的动脉瘤性SAH患者进行早期识别。更多还原

【Abstract】 Objective To assess the diagnostic accuracy of CT perfusion (CTP) during admission baseline period defined as days 0-3 following aneurysmal subarachnoid hemorrhage (A-SAH) for the prediction of development of delayed cerebral ischemia (DCI). Methods CTP image data of baseline and 1 week after onset about 54 A-SAH patients from Aug 2011 to Sep 2012 were retrospectively studied. Relative cerebral blood volume (rCBV),relative cerebral blood flow (rCBF) and relative mean transit time (rMTT) were measured. ROI was performed in anterior cerebral artery area (ACA area),middle cerebral artery area (MCA area),basal ganglia area,posterior cerebral artery area (PCA area),front and back watershed area. Patients were divided into DCI and no DCI groups by combination of non-contrast CT,CTP reexamination and clinical assessment of neurological deficits. Quantitative baseline and reexamination PCT data for all patients were evaluated for statistically significant differences between DCI and no DCI groups utilizing Student’ s t test.Compare the quantitative baseline and PCT reexamination data of DCI with paired Student’ s t test. Baseline rCBF was divided into three groups as rCBF≤0. 75,ranged from 0. 75 to 0. 85 and rCBF≥0. 85,and the χ2test was used to evaluate difference of incidence of DCI between them. Statistical analysis was conducted using SPSS 16. 0 software and statistical significance was accepted at P < 0. 05. The optimal cut-off value for each relative PCT parameter was established by receiver operating characteristic( ROC) curve analysis using MedCalc 9. 6 2. 0 software. Results 33. 3%( 18 /54) developed DCI. Mean relative baseline CTP values in DCI compared to no DCI groups were rCBF 0. 78 vs. 1. 01( t = 6. 63,P < 0. 01),rMTT 1. 24 vs. 0. 96( t =5. 29,P < 0. 01),and rCBV 0. 90 vs. 1. 01(t = 4. 43,P < 0. 01). In DCI patients,reexamination rCBF decreased( t = 3. 18,P < 0. 05),rCBV decreased( t = 2. 83,P < 0. 05) compared to baseline,and there was no difference on rMTT (t = 0. 99,P = 0. 38). Statistical difference was found among different baseline rCBF subsets( χ2= 38. 00,P < 0. 05). Optimal threshold for baseline rCBF was 0. 84 with 87. 5% specificity and90. 62% sensitivity,area under the ROC curve (AUC) was 0. 945( 95% CI: 0. 824-0. 992),rMTT was 1. 1with 75% specificity and 84. 37% sensitivity,AUC was 0. 844( 95% CI: 0. 694-0. 939),rCBV 0. 94 with75% specificity and 71. 87% sensitivity,AUC was 0. 781(95% CI: 0. 622-0. 896). Conclusions Using PCT during the baseline period can make early identification of A-SAH patients at high risk for DCI.更多还原