Fig. 2

Lung ultrasound. A Transversal scan of an anterior intercostal space: the probe is tilted to be perpendicular to the pleura. In the corresponding ultrasound image (B), the pleural line and one A-line (white arrow) are well visible. One focus is correctly set on the pleura (yellow triangle). C In the same intercostal space, the probe is not correctly tilted and is not perpendicular to the probe. In fact, in the corresponding scan, the A-line is not visible anymore (D); moreover, the focus is set too deep, leading to a less distinct visualization of the pleural line. E The 6 regions per hemithorax of a standard lung ultrasound examination. Anterior fields (1 and 2) are identified by sternum and anterior axillary line, lateral fields (3 and 4) by anterior and posterior axillary lines, posterior fields are accessible below the posterior axillary lines (5 and 6). The patient can lie supine with no need to turn him/her to visualize posterior fields