A Quantitative Approach to Distinguish Pneumonia From Atelectasis Using Computed Tomography Attenuation
A Quantitative Approach to Distinguish Pneumonia From Atelectasis Using Computed Tomography Attenuation
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DOI：
10.1097/rct.0000000000000438
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发表时间：
2016-09-01
影响因子：
1.3
通讯作者：
Kicska, Gregory
中科院分区：
文献类型：
--
作者：
Edwards, Rachael M.;Godwin, J. David;Kicska, Gregory
目的肺不张在CT上比肺炎有更强的增强。然而，使用Hounsfield单位（HU）阈值区分肺炎和肺不张的有效性从未被证明。该研究的目的是证明，HU阈值可以定量地用于有效区分肺炎肺不张。方法retroperitoneidentified CT肺血管造影检查，没有显示肺栓塞，但包含nonaerated肺被归类为肺不张或肺炎的基础上建立的临床标准。在这些非充气肺中测量HU衰减。进行受试者工作特征（ROC）分析，以确定ROC曲线下面积，灵敏度和特异性的衰减，以区分肺炎肺不张。肺炎平均增强62（18）HU，肺不张平均增强119（24）HU（P < 0.001）。92 HU的阈值诊断肺炎具有97%的灵敏度（置信区间[CI]，80%-99%）和85%的特异性（CI，70-93）。准确性，测量ROC曲线下的面积，是0.97（CI，0.89-0.99）。结论我们已经建立了一个阈值HU值可以用来自信地区分肺炎肺不张与我们的标准CT肺血管造影成像协议和患者人群。这表明可以为其他扫描协议确定类似的阈值HU值，并且该阈值的应用可以促进肺炎的更有把握的诊断，从而加速治疗。
Objective It is known that atelectasis demonstrates greater contrast enhancement than pneumonia on computed tomography (CT). However, the effectiveness of using a Hounsfield unit (HU) threshold to distinguish pneumonia from atelectasis has never been shown. The objective of the study is to demonstrate that an HU threshold can be quantitatively used to effectively distinguish pneumonia from atelectasis.Methods Retrospectively identified CT pulmonary angiogram examinations that did not show pulmonary embolism but contained nonaerated lungs were classified as atelectasis or pneumonia based on established clinical criteria. The HU attenuation was measured in these nonaerated lungs. Receiver operating characteristic (ROC) analysis was performed to determine the area under the ROC curve, sensitivity, and specificity of using the attenuation to distinguish pneumonia from atelectasis.Results Sixty-eight nonaerated lungs were measured in 55 patients. The mean (SD) enhancement was 62 (18) HU in pneumonia and 119 (24) HU in atelectasis (P < 0.001). A threshold of 92 HU diagnosed pneumonia with 97% sensitivity (confidence interval [CI], 80%-99%) and 85% specificity (CI, 70-93). Accuracy, measured as area under the ROC curve, was 0.97 (CI, 0.89-0.99).Conclusions We have established that a threshold HU value can be used to confidently distinguish pneumonia from atelectasis with our standard CT pulmonary angiogram imaging protocol and patient population. This suggests that a similar threshold HU value may be determined for other scanning protocols, and application of this threshold may facilitate a more confident diagnosis of pneumonia and thus speed treatment.