Guiloff, StefanSilva, Claudio2017-08-102017-08-102016Rev Chil Rad. 2016; 22(2):92-95http://hdl.handle.net/11447/1558http://dx.doi.org/10.1016/j.rchira.2016.06.006The Luftsichel sign corresponds to a crescent-shaped paraaortic hyperlucency in frontal chest radiograph caused by the collapse of the left upper lobe. Its recognition is relevant, especially in adult patients, where we should considered an endobronchial neoplasia as the first possible etiology of the lobar collapse. The differential diagnosis includes the right lung herniation through the midline, medial pneumothorax, pneumomediastinum and bullous disease.4spaLobar lung collapseChestLuftsichelRadiographyArtículo