Woodring J H
Department of Diagnostic Radiology, A. B. Chandler Medical Center, University of Kentucky, Lexington 40536-0084.
AJR Am J Roentgenol. 1988 Apr;150(4):757-63. doi: 10.2214/ajr.150.4.757.
In a retrospective analysis of 50 patients with segmental or lobar atelectasis of the lung, chest radiographs and CT studies were compared for their abilities to distinguish whether a centrally obstructing tumor was the cause. This was done to help define the role of CT in evaluating patients with atelectasis. Atelectasis was caused by an obstructing tumor in 27 cases and a variety of other conditions in 23. The chest radiograph correctly identified an obstructing tumor as the cause of atelectasis in 24 of 27 patients on the basis of the presence of a central hilar mass or obvious bronchial abnormality; there was 89% sensitivity and 96% specificity with a 12% false-negative rate and a 4% false-positive rate. CT correctly identified all 27 obstructing carcinomas on the basis of the presence of either a central bronchial abnormality or a central hilar mass; there was 100% sensitivity and 87% specificity with a 0% false-negative rate and a 10% false-positive rate. Absence of air bronchograms or the presence of mucus-filled bronchi within the atelectatic lung were secondary CT findings that also favored the presence of an obstructing tumor. Although the chest radiograph was more specific than CT for tumor as the cause of atelectasis (96% vs 87%, respectively), it was less sensitive than CT for tumor (89% vs 100%, respectively) resulting in missed tumor diagnoses. CT identified all cases caused by obstructing tumor and successfully excluded obstructing tumor in most of the remaining cases, with an acceptable number of false-positive tumor diagnoses (10%). CT should be performed when the cause of segmental or lobar atelectasis cannot be established with certainty on the basis of the chest radiograph.
在一项对50例肺段或肺叶肺不张患者的回顾性分析中，比较了胸部X光片和CT检查区分中央型阻塞性肿瘤是否为病因的能力。这样做是为了明确CT在评估肺不张患者中的作用。27例肺不张由阻塞性肿瘤引起，23例由多种其他情况引起。胸部X光片在27例患者中的24例中，根据中央肺门肿块或明显支气管异常的存在，正确地将阻塞性肿瘤识别为肺不张的病因；敏感性为89%，特异性为96%，假阴性率为12%，假阳性率为4%。CT根据中央支气管异常或中央肺门肿块的存在，正确识别了所有27例阻塞性癌；敏感性为100%，特异性为87%，假阴性率为0%，假阳性率为10%。肺不张肺内无空气支气管造影或存在充满黏液的支气管是CT的次要表现，也提示存在阻塞性肿瘤。尽管胸部X光片在将肿瘤作为肺不张病因方面比CT更具特异性（分别为96%和87%），但在检测肿瘤方面比CT更不敏感（分别为89%和100%），导致肿瘤诊断漏诊。CT识别了所有由阻塞性肿瘤引起的病例，并在大多数其余病例中成功排除了阻塞性肿瘤，假阳性肿瘤诊断数量可接受（10%）。当根据胸部X光片不能确定肺段或肺叶肺不张的病因时，应进行CT检查。
