Fig. 2From: The “pandemic” increase in lung ultrasound use in response to Covid-19: can we complement computed tomography findings? A narrative reviewB-lines. Hyperechoic artifacts descending from the pleural line to the bottom of the screen are called “B lines” (black asterisks); by definition, a B line obscures any A line along its path. Two B lines per scan field are considered normal; ≥ 3 lines are associated with varying degrees of interstitial syndromeBack to article page