Figure 2.

Lung rockets.

The B-line includes 7 criteria. Three are constant: 1) This is a comet-tail, vertical artifact. 2) It arises from the pleural line. 3) It moves in concert with lung sliding. Four criteria are quite always present. 4) It does not fade, descends up to the edge of the screen. 5) It is well-defined, laser like. 6) It is hyperechoic, like the pleural line. 7) It obliterates the A-lines. All these criteria make it always possible to recognize B-lines from other comet-tail artifacts (E-lines, Z-lines...).

The B-line can be isolated, with little meaning. Multiple B-lines, like in this view (three being visible), are then called “lung rockets”, and indicate interstitial syndrome - usually interstitial edema when seen in acute settings.