Pulmonary Edema

Look for B-lines which how as vertical echogenic short artifacts. They start at the pleural line and extend down through the ultrasound image.

Occasional B-lines are considered normal. However, more than 3 in a single view is abnormal. Sometimes, there are numerous B-lines in close proximity and they become confluent.

B-lines can originate from cardiogenic and noncardiogenic pulmonary edema.

Interstitial thickening due to fibrosis or lymphangitis can also create the sonographic appearance of diffuse B-lines.


  • B-line interrupt any horizontal A-lines.
  • B-lines move with lung movement.
  • Other pathological processes such a pulmonary fibrosis can create the appearance of diffuse B-lines.

Figures and Clips

Figure 1 - B-lines

Clip 1 - B-lines

Clip 2 - Confluent B-lines


Lichtenstein, Daniel A. “Lung ultrasound in the critically ill.” Annals of intensive care 4.1 (2014): 1.