Using quantitative CT perfusion for evaluation of delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage.
Using quantitative CT perfusion for evaluation of delayed cerebral ischemia following aneurysmal subarachnoid hemorrhage.
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DOI：
10.3174/ajnr.a2693
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发表时间：
2011-12
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影响因子：
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通讯作者：
Mushlin AI
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作者：
Sanelli PC;Ugorec I;Johnson CE;Tan J;Segal AZ;Fink M;Heier LA;Tsiouris AJ;Comunale JP;John M;Stieg PE;Zimmerman RD;Mushlin AI
前瞻性评价CT灌注成像（CTP）诊断蛛网膜下腔出血（SAH）迟发性脑缺血（DCI）的准确性，并确定量化阈值。SAH患者前瞻性入组IRB批准的方案。CTP在DCI的典型时间段内进行，在SAH后第6-8天之间。定量脑血流量（CBF），脑血容量（CBV）和平均通过时间（MTT）值使用标准的感兴趣区域放置采样灰质。DCI的参考标准是有争议的，包括临床和影像学标准在这项研究中。在血管痉挛的亚组分析中，数字减影血管造影术被用作参考标准。受试者工作特征曲线使用曲线下面积确定诊断准确性。采用患者群体效用法计算最佳阈值。纳入97例患者; 41%（40/97）患有DCI。总体诊断准确率为93%CBF，88%MTT和72%CBV。CBF的最佳阈值为35 mL/100 gm/min（敏感性90%，特异性68%），MTT的最佳阈值为5.5sec（敏感性73%，特异性79%）。在亚组分析（n=57）中，63%（36/57）发生血管痉挛。总体诊断准确率为94%CBF，85%MTT和72%CBV。最佳阈值CBF为36.5mL/100 gm/min（敏感性95%，特异性70%），MTT为5.4s（敏感性78%，特异性70%）。CBF和MTT的总体诊断准确率最高。基于患者群体效用方法，建议DCI的阈值为35 mL/100 gm/min CBF和5.5sec MTT。由于扫描仪设备和后处理方法的差异，绝对阈值可能无法推广。
To prospectively evaluate the diagnostic accuracy of CT perfusion (CTP) and determine a quantitative threshold for delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (SAH). SAH patients were prospectively enrolled in an IRB approved protocol. CTP was performed during the typical time-period for DCI, between days 6–8 following SAH. Quantitative cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) values were obtained using standard region-of-interest placement sampling gray matter. The reference standard for DCI is controversial and consisted of clinical and imaging criteria in this study. In a subanalysis of vasospasm, digital subtraction angiography was used as the reference standard. Receiver operating characteristic curves determined diagnostic accuracy using area under the curve. Optimal threshold values were calculated using patient population utility method. Ninety-seven patients were included; 41% (40/97) had DCI. Overall diagnostic accuracy was 93% CBF, 88% MTT and 72% CBV. Optimal threshold values were 35mL/100gm/min (90% sensitivity,68% specificity) for CBF and 5.5sec (73% sensitivity,79% specificity) for MTT. In the subanalysis (n=57), 63% (36/57) had vasospasm. Overall diagnostic accuracy was 94% CBF, 85% MTT and 72% CBV. Optimal threshold values were 36.5 mL/100gm/min (95% sensitivity,70% specificity) for CBF and 5.4 sec (78% sensitivity,70% specificity) for MTT. CBF and MTT have the highest overall diagnostic accuracy. Threshold values of 35mL/100gm/min CBF and 5.5sec MTT are suggested for DCI based on patient population utility method. Absolute threshold values may not be generalizable due to differences in scanner equipment and post-processing methods.