Johnston D C, Goldstein L B
Department of Medicine (Neurology), Duke Center for Cerebrovascular Disease, Center for Clinical Health Policy Research, Duke University, Durham, NC, USA.
Neurology. 2001 Apr 24;56(8):1009-15. doi: 10.1212/wnl.56.8.1009.
Carotid endarterectomy (CEA) is frequently performed based solely on noninvasive vascular imaging (NVI) results (duplex ultrasound, DU; magnetic resonance angiography, MRA; CT angiography, CTA). The authors determined how often intra-arterial contrast angiography (ANGIO) alters a CEA decision as compared to NVI in clinical practice.
Reports of all NVI studies in 569 consecutive patients undergoing ANGIO at an academic medical center (AMC, n = 360) and a community hospital (CH, n = 209) over 3 years were reviewed. Patients were classified as to whether CEA was indicated based on each study. Misclassification rates, sensitivities, specificities, positive (PPV) and negative (NPV) predictive values were calculated.
CTA was performed infrequently (2.5%) and not considered further. Misclassification rates for CEA based on DU in the AMC and CH were similar. The misclassification rate for DU alone was 28% (95% CI: 24,32), and for MRA alone was 18% (95% CI: 11,25). Both NVI were done in 11% of patients, with a misclassification rate of 7.9% (95% CI: 0,16) when the two were concordant (76% of studies). DU had a sensitivity of 87% (95% CI: 83,91), specificity 46% (95% CI: 38,54), PPV 73% (95% CI: 68,78) and NPV 68% (95% CI: 60,77). MRA had a sensitivity of 75% (95% CI: 63,87), specificity 88% (95% CI: 80,96), PPV 84% (95% CI: 73,95) and NPV 80% (95% CI: 70, 90). The sensitivity of concordant NVIs was 96% (95% CI: 88,100), specificity 85% (95% CI: 65,100), PPV 93% (95% CI: 81,100) and NPV 92% (95% CI: 76,100).
These data suggest that surgical decisions should be made with caution if based on the results of noninvasive studies, particularly DU performed alone. Concordant DU and MRA results in a lower misclassification rate than either test used alone.
颈动脉内膜切除术（CEA）常常仅基于非侵入性血管成像（NVI）结果（双功超声，DU；磁共振血管造影，MRA；CT血管造影，CTA）来实施。作者确定了在临床实践中，与NVI相比，动脉内对比血管造影（ANGIO）改变CEA决策的频率。
回顾了一家学术医疗中心（AMC，n = 360）和一家社区医院（CH，n = 209）在3年期间对569例接受ANGIO的连续患者进行的所有NVI研究报告。根据每项研究对患者是否需要进行CEA进行分类。计算错误分类率、敏感性、特异性、阳性（PPV）和阴性（NPV）预测值。
CTA实施频率较低（2.5%），未作进一步考虑。AMC和CH中基于DU的CEA错误分类率相似。单独使用DU的错误分类率为28%（95%可信区间：24,32），单独使用MRA的错误分类率为18%（95%可信区间：11,25）。11%的患者同时进行了两种NVI检查，当两者结果一致时（76%的研究），错误分类率为7.9%（95%可信区间：0,16）。DU的敏感性为87%（95%可信区间：83,91），特异性为46%（95%可信区间：38,54），PPV为73%（95%可信区间：68,78），NPV为68%（95%可信区间：60,77）。MRA的敏感性为75%（95%可信区间：63,87），特异性为88%（95%可信区间：80,96），PPV为84%（95%可信区间：73,95），NPV为80%（95%可信区间：70,90）。一致的NVI的敏感性为96%（95%可信区间：88,100），特异性为85%（95%可信区间：65,100），PPV为93%（95%可信区间：81,100），NPV为92%（95%可信区间：76,100）。
这些数据表明，如果基于非侵入性研究的结果，尤其是单独进行的DU检查结果来做出手术决策，应谨慎行事。DU和MRA结果一致时的错误分类率低于单独使用任何一种检查。
