Stage Ⅰ Central Lung Cancer and Bronchial Disseminated Pulmonary Tuberculosis: A Comparative Analysis of Tree-in-bud Sign at CT / 中国医学影像学杂志

ABSTRACT

Purpose To investigate the difference of imaging features of tree-in-bud (TIB) sign at CT between stage Ⅰ central lung cancer and bronchial disseminated pulmonary tuberculosis in order to reduce the misdiagnosis rate of central lung cancer.Materials and Methods 32 patients of stage Ⅰ central type lung cancer confirmed pathologically or clinically (lung cancer group) and 47 patients of bronchial disseminated pulmonary tuberculosis confirmed pathologically or clinically (tuberculosis group) underwent chest CT scanning and were found with TIB sign.The imaging data of all the cases were analyzed retrospectively in terms of distribution range,accompanying CT findings of TIB sign,and abnormalities of segmental and (or) larger bronchus proximal to it.Results TIB sign was mainly focal (unilobar) in lung cancer group (96.88％),while it was mainly diffuse (more than one pulmonary lobe) in tuberculosis group (80.85％).The difference was significant (P＜0.01).Accompanying CT findings:① Obstructive bronchial mucoid impaction distal to the TIB was more common in lung cancer group than in tuberculosis group (100％ vs 6.38％,P＜0.01).② Consolidation and/or ground-glass opacities were found both in lung cancer group (34.38％) and in tuberculosis group (48.94％).The difference was not significant (P＞0.05).③ Cavity was less common in lung cancer group than in tuberculosis group (0 vs 38.30％,P＜0.01).④ Nodules with diameter larger than 5 mm were much fewer in lung cancer group than in tuberculosis group (0 vs 76.60％,P＜0.01).TIB sign was found in 33 lobes in lung cancer group,and the abnormity was found in all these lobes (100％);while in tuberculosis group,TIB sign was found in 144 lobes and the abnormity was found in 56 lobes (38.89％).Conclusion TIB sign shows differences between stage Ⅰ central lung cancer and bronchial disseminated pulmonary tuberculosis.The TIB signs such as focal distribution,accompanied by bronchial mucoid impaction and abnormality of segmental or (and) larger bronchus may predict the high possibility of central lung cancer.