Quiroz Rene, Kucher Nils, Zou Kelly H, Kipfmueller Florian, Costello Philip, Goldhaber Samuel Z, Schoepf U Joseph
Department of Radiology, Brigham and Women's Hospital, Boston, Mass, USA.
JAMA. 2005 Apr 27;293(16):2012-7. doi: 10.1001/jama.293.16.2012.
The clinical validity of using computed tomography (CT) to diagnose peripheral pulmonary embolism is uncertain. Insufficient sensitivity for peripheral pulmonary embolism is considered the principal limitation of CT.
To review studies that used a CT-based approach to rule out a diagnosis of pulmonary embolism.
The medical literature databases of PubMed, MEDLINE, EMBASE, CRISP, metaRegister of Controlled Trials, and Cochrane were searched for articles published in the English language from January 1990 to May 2004.
We included studies that used contrast-enhanced chest CT to rule out the diagnosis of acute pulmonary embolism, had a minimum follow-up of 3 months, and had study populations of more than 30 patients.
Two reviewers independently abstracted patient demographics, frequency of venous thromboembolic events (VTEs), CT modality (single-slice CT, multidetector-row CT, or electron-beam CT), false-negative results, and deaths attributable to pulmonary embolism. To calculate the overall negative likelihood ratio (NLR) of a VTE after a negative or inconclusive chest CT scan for pulmonary embolism, we included VTEs that were objectively confirmed by an additional imaging test despite a negative or inconclusive CT scan and objectively confirmed VTEs that occurred during clinical follow-up of at least 3 months.
Fifteen studies met the inclusion criteria and contained a total of 3500 patients who were evaluated from October 1994 through April 2002. The overall NLR of a VTE after a negative chest CT scan for pulmonary embolism was 0.07 (95% confidence interval [CI], 0.05-0.11); and the negative predictive value (NPV) was 99.1% (95% CI, 98.7%-99.5%). The NLR of a VTE after a negative single-slice spiral CT scan for pulmonary embolism was 0.08 (95% CI, 0.05-0.13); and after a negative multidetector-row CT scan, 0.15 (95% CI, 0.05-0.43). There was no difference in risk of VTEs based on CT modality used (relative risk, 1.66; 95% CI, 0.47-5.94; P = .50). The overall NLR of mortality attributable to pulmonary embolism was 0.01 (95% CI, 0.01-0.02) and the overall NPV was 99.4% (95% CI, 98.7%-99.9%).
The clinical validity of using a CT scan to rule out pulmonary embolism is similar to that reported for conventional pulmonary angiography.
使用计算机断层扫描（CT）诊断外周肺栓塞的临床有效性尚不确定。外周肺栓塞的敏感性不足被认为是CT的主要局限性。
回顾使用基于CT的方法排除肺栓塞诊断的研究。
检索了PubMed、MEDLINE、EMBASE、CRISP、对照试验元注册库和Cochrane的医学文献数据库，以查找1990年1月至2004年5月发表的英文文章。
我们纳入了使用对比增强胸部CT排除急性肺栓塞诊断、至少随访3个月且研究人群超过30例患者的研究。
两名研究者独立提取患者人口统计学信息、静脉血栓栓塞事件（VTE）的发生率、CT检查方式（单层CT、多层螺旋CT或电子束CT）、假阴性结果以及肺栓塞所致死亡情况。为计算肺栓塞胸部CT扫描结果为阴性或不确定后VTE的总体阴性似然比（NLR），我们纳入了尽管CT扫描结果为阴性或不确定但通过额外影像学检查客观证实的VTE，以及在至少3个月的临床随访期间客观证实的VTE。
15项研究符合纳入标准，共纳入了1994年10月至2002年4月期间接受评估的3500例患者。肺栓塞胸部CT扫描结果为阴性后VTE的总体NLR为0.07（95%置信区间[CI]，0.05 - 0.11）；阴性预测值（NPV）为99.1%（95%CI，98.7% - 99.5%）。肺栓塞单层螺旋CT扫描结果为阴性后VTE的NLR为0.08（95%CI，0.05 - 0.13）；多层螺旋CT扫描结果为阴性后，NLR为0.15（95%CI，0.05 - 0.43）。基于所使用的CT检查方式，VTE风险无差异（相对风险，1.66；95%CI，0.47 - 5.94；P = 0.50）。肺栓塞所致死亡的总体NLR为0.01（95%CI，0.01 - 0.02），总体NPV为99.4%（95%CI，98.7% - 99.9%）。
使用CT扫描排除肺栓塞的临床有效性与传统肺血管造影报告的相似。
