Fig. 1

Lung sonography results. Patients with avian-origin influenza A (H7N9) virus were subjected to lung sonography analysis. □ B line; △ pleural effusion; ◯ consolidation; → air bronchography sign. a B line perpendicular to the pleura with a linear probe, namely, an isolated comet-tail sign. b: Four B lines with a linear probe, namely, a multiple comet-tail sign. c: Multiple comet-tail signs and pleural effusion with a convex array probe. d: Pleural effusion, lung consolidation, and air bronchography sign with a convex array probe. e: Disappearance of pleural sliding using a linear probe when the pneumothorax, stratosphere sign, and barcode sign were in the M modes