Fig. 2.

Lung ultrasound examination performed with a high-frequency linear probe (15–7 MHz) in healthy adults (a–d), longitudinal view. A-lines (a) with schematic representation (b): there is a good anatomical definition of the pleural hyperechoic reflection (b thickened blue line) with evidence of multiple horizontal reverberation artifacts or A-lines (b, transparent blue boxes) parallel to the hyperechoic “pleural line” and equidistant between them. B-lines (c) with schematic representation (d): multiple hyperechogenic linear structures or ring-down artifacts (c) come from the hyperechoic pleural line (d thickened blue line) caudally for several cm (d blue vertical trapezoids)