Gaeta M, Minutoli F, Ascenti G, Vinci S, Mazziotti S, Pandolfo I, Blandino A
Institute of Radiological Sciences, University of Messina, Messina, Italy.
J Comput Assist Tomogr. 2001 Nov-Dec;25(6):890-6. doi: 10.1097/00004728-200111000-00011.
The presence of a pulmonary consolidation with a signal intensity comparable with that of the static fluid on heavily T2-weighted MR images has been named the "MR white lung sign." This sign has been described in mucinous bronchioloalveolar carcinoma (BAC). Our purpose was to establish the frequency and significance of this sign in pulmonary consolidations of varied causes.
In this prospective study, 83 patients with pulmonary consolidation underwent MR examination between January and December 1999. Segmental or lobar consolidations were due to pneumonia without central obstruction (n = 22), pneumonitis with central obstruction (n = 21), cicatricial atelectasis (n = 8), passive atelectasis (n = 10), radiation pneumonitis (n = 8), mucinous BAC (n = 5), infarction (n = 3), bronchiolitis obliterans organizing pneumonia (n = 3), nonmucinous BAC (n = 2), and lymphoma (n = 1). The MR white lung sign was considered present when the signal intensity of a pulmonary consolidation was comparable with that of the static fluid on heavily T2-weighted images obtained with MR hydrography sequences. Interobserver agreement, sensitivity, and specificity of the white lung sign in diagnosing mucinous BAC were calculated.
The MR white lung sign was present in 7 (8%) of 83 consolidations, including 5 (100%) of 5 cases of mucinous BAC and 2 (10%) of 21 cases of obstructive pneumonitis. The frequency of the white lung sign was 100% in mucinous BAC and 2.6% in consolidations due to other causes. The difference was statistically significant (p < 0.05).
The white lung sign is an uncommon finding in pulmonary consolidations evaluated with heavily T2-weighted sequences. However, the sign is characteristic of mucinous BAC and adds specificity to the radiologic diagnosis.
在重度T2加权磁共振成像（MR）上，肺部实变的信号强度与静态液体相当，这种表现被称为“MR白肺征”。该征象已在黏液性细支气管肺泡癌（BAC）中被描述。我们的目的是确定此征象在各种原因导致的肺部实变中的出现频率及意义。
在这项前瞻性研究中，1999年1月至12月期间，83例肺部实变患者接受了MR检查。节段性或大叶性实变的病因包括无中央阻塞的肺炎（n = 22）、有中央阻塞的肺炎（n = 21）、瘢痕性肺不张（n = 8）、被动性肺不张（n = 10）、放射性肺炎（n = 8）、黏液性BAC（n = 5）、梗死（n = 3）、闭塞性细支气管炎伴机化性肺炎（n = 3）、非黏液性BAC（n = 2）和淋巴瘤（n = 1）。当肺部实变的信号强度与采用MR水成像序列获得的重度T2加权图像上的静态液体信号强度相当时，即认为存在MR白肺征。计算白肺征在诊断黏液性BAC时的观察者间一致性、敏感性和特异性。
83例实变中7例（8%）出现MR白肺征，其中黏液性BAC 5例（100%），阻塞性肺炎21例中的2例（10%）。白肺征在黏液性BAC中的出现频率为100%，在其他原因导致的实变中为2.6%。差异具有统计学意义（p < 0.05）。
在采用重度T2加权序列评估的肺部实变中，白肺征是一种不常见的表现。然而，该征象是黏液性BAC的特征性表现，可为放射学诊断增加特异性。
