BACKGROUND Computed tomography pulmonary angiography (CTPA) is the gold standard for the diagnosis of pulmonary embolism (PE). However, contrast is contraindicated in some patients. The purpose of this study was to determine the diagnostic accuracy of unenhanced multidetector CT (MDCT) for diagnosis of central PE using CTPA as the gold standard. METHODS The records of patients with suspected PE seen between 2010 and 2013 were retrospectively reviewed. Inclusion criteria were an acute, central PE confirmed by CTPA and non-enhanced MDCT before contrast injection. Patients with a PE ruled out by CTPA served as a control group. MDCT findings studied were high-attenuation emboli in pulmonary artery (PA), main PA dilatation > 33.2 mm, and peripheral wedge-shaped consolidation. Receiver operating characteristic (ROC) analysis was used to determine the sensitivity and specificity of unenhanced MDCT to detect PE. Wells score of all patients were calculated using data extracted from medical records prior to imaging analysis. RESULTS Thirty-two patients with a PE confirmed by CTPA and 32 with a PE ruled out by CTPA were included. Among the three main MDCT findings, high-attenuation emboli in the PA showed best diagnostic performance (Sensitivity 72.9%; Specificity 100%), followed by main PA dilatation > 33.2 mm (sensitivity 46.9%; specificity 90.6%), and peripheral wedge-shaped consolidation (sensitivity 43.8%; specificity 78.1%). Given any one or more positive findings on unenhanced MDCT, the sensitivity was 96.9% and specificity was 71.9% for a diagnosis of PE in patients. The area under the curve (AUC) of a composite measure of unenhanced MDCT findings (0.909) was significantly higher than that of the Wells score (0.688), indicating unenhanced MDCT was reliable for detecting PE than Wells score. CONCLUSIONS Unenhanced MDCT is an alternative for the diagnosis of acute central PE when CTPA is not available.

中文翻译：

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急性中枢性肺栓塞未增强的多探测器计算机断层扫描发现。

背景技术计算机断层扫描肺血管造影（CTPA）是诊断肺栓塞（PE）的金标准。但是，在某些患者中，造影剂是禁忌的。这项研究的目的是确定使用CTPA作为金标准的无增强型多探测器CT（MDCT）诊断中心性PE的诊断准确性。方法回顾性分析2010年至2013年间疑似PE患者的病历。纳入标准为在造影剂注射之前由CTPA和未增强的MDCT确认的急性中心性PE。CTPA排除PE的患者作为对照组。MDCT的研究结果是肺动脉（PA）的高衰减栓子，主要PA扩张> 33.2 mm和周围楔形固形。接收者操作特征（ROC）分析用于确定未增强MDCT检测PE的敏感性和特异性。所有患者的Wells分数均使用影像分析之前从病历中提取的数据计算得出。结果纳入了32例经CTPA确诊的PE和32例经CTPA排除的PE的患者。在这三个MDCT的主要发现中，PA的高衰减栓子表现出最佳的诊断性能（敏感性72.9％；特异性100％），其次是PA的主要扩张> 33.2 mm（敏感性46.9％；特异性90.6％）和周围楔形-整形（敏感性43.8％；特异性78.1％）。鉴于未增强MDCT的任何一项或多项阳性发现，诊断患者PE的敏感性为96.9％，特异性为71.9％。MDCT未增强发现的综合量度（0.909）的曲线下面积（AUC）明显高于Wells得分（0.688），表明MDCT比Wells得分更可靠地检测PE。结论当CTPA不可用时，未增强的MDCT可作为诊断急性中枢性PE的替代方法。