Image Genevieve Carbonatto Widespread B lines originating from the pleural line
Acute pulmonary oedema
The causes of an interstitial syndrome includes, pulmonary edema of various causes, interstitial pneumonia or pneumonitis and diffuse parenchymal lung disease (pulmonary fibrosis)
The clinical scenario will help differentiate between them. There are subtle sonographic differences however. B lines are seen in pulmonary oedema throughout the chest and there are no pleural line abnormalities. 3 or more B lines need to be present at the same time between 2 rib spaces for these to be pathological andfor these to indicate an interstitial syndrome
B lines are characterised by 7 features
- It is a comet tail artifact
- It arises from the pleural line
- It is well defined and laser like
- It is hyperechoic
- It is long, spreading out without fading to the edge of the screen
- It erases or obliterates the A lines
- It moves with lung sliding
Lichtenstein : Whole body ultrasonography in critical care p 152
