[Lung rounded atelectasis. A benign lesion due to asbestos]

[Manifestations of lobar atelectasis on chest x-rays and correlation with computed tomography findings]

Atelectasis is an important indicator of potentially severe underlying disease that must be diagnosed as early as possible. One of the most common mechanisms is the reabsorption of air distal to respiratory tract obstruction. The chest x-ray is an excellent tool to diagnose atelectasis, and it is especially useful for ruling out central bronchial obstructions (e.g., from endobronchial tumors). If the signs of volume loss are not recognized correctly, the diagnosis and treatment can be delayed. This article describes the main findings of lobar atelectasis on chest x-rays and their correlations with CT findings, including the classic signs described in the literature and other, less known and sometimes subtle signs.