Chaudhary Saadia R, Ko Nerissa, Dillon William P, Yu Melissa B, Liu Songling, Criqui Geoffrey I, Higashida Randall T, Smith Wade S, Wintermark Max
Neuroradiology Section, Department of Radiology, University of California, San Francisco, CA 94143-0628, USA.
Cerebrovasc Dis. 2008;25(1-2):144-50. doi: 10.1159/000112325. Epub 2007 Dec 11.
To evaluate the accuracy of multidetector-row CT angiography (CTA) for the diagnosis of large-vessel vasospasm following subarachnoid hemorrhage by comparison to digital subtraction angiography (DSA).
Thirty-three patients with acute subarachnoid hemorrhage were enrolled in a prospective study and underwent a total of 40 CTA and DSA examinations within 24 h of each other. Two neuroradiologists reviewed the CTA examinations independently. A third neuroradiologist blinded to the CTA results reviewed the DSA examinations. In each patient, for both techniques, 23 arterial segments were evaluated for their degree of narrowing; the reviewers were asked to attribute every narrowing to 'vasospasm' or 'hypoplasia'. Agreement between CTA and DSA for the degree of narrowing, and agreement between the two CTA readers, were calculated using weighted kappa-coefficients. Sensitivity, specificity, accuracy, positive and negative predictive value (NPV) of CTA to detect large-vessel vasospasm were calculated considering DSA as the gold standard.
Substantial correlation (kappa = 0.638) was found between CTA and DSA for the detection of arterial narrowing. Interobserver agreement between the two CTA reviewers for the degree of luminal narrowing was substantial (kappa = 0.712).CTA was 87% accurate for the diagnosis of large-vessel vasospasm; the NPV of CTA was 95%. CTA was more accurate, and interobserver agreement higher, for the proximal arterial segments (basilar and vertebral arteries) than for the distal ones (P2 segments). Using CTA as a screening modality, 83% of unnecessary DSA would have been avoided.
Compared to the gold standard of DSA, CTA is accurate for the detection of large-vessel vasospasm, and has a very high NPV.
通过与数字减影血管造影（DSA）对比，评估多排螺旋CT血管造影（CTA）诊断蛛网膜下腔出血后大血管痉挛的准确性。
33例急性蛛网膜下腔出血患者纳入一项前瞻性研究，在彼此24小时内共接受40次CTA和DSA检查。两名神经放射科医生独立审查CTA检查。一名对CTA结果不知情的第三位神经放射科医生审查DSA检查。对每位患者，两种技术均评估23个动脉节段的狭窄程度；要求审查人员将每个狭窄归因于“血管痉挛”或“发育不全”。使用加权kappa系数计算CTA和DSA之间狭窄程度的一致性，以及两位CTA阅片者之间的一致性。以DSA为金标准，计算CTA检测大血管痉挛的敏感性、特异性、准确性、阳性和阴性预测值（NPV）。
CTA和DSA在检测动脉狭窄方面存在显著相关性（kappa = 0.638）。两位CTA审查者之间关于管腔狭窄程度的观察者间一致性较高（kappa = 0.712）。CTA诊断大血管痉挛的准确率为87%；CTA的NPV为95%。对于近端动脉节段（基底动脉和椎动脉），CTA比远端节段（P2节段）更准确，观察者间一致性更高（P < 0.001）。将CTA用作筛查方式，可避免83%不必要的DSA检查。
与DSA金标准相比，CTA在检测大血管痉挛方面准确，且NPV非常高。
