- Indicates interstitial fluid
Alveolar interstitial syndrome (AIS)
- Pulmonary edema – CHF
- Acute respiratory distress syndrome (ARDS)
- Pulmonary contusion
- Anterior superior lung field most high yield
So, when you’re looking for B lines, you can interrogate four areas of the chest, both the anterior lateral, superior, and inferior and you can count the lines if you want, although in my experience, most commonly it’s area one, which is the anterior superior space that is most helpful to tell us if there are pathologic B lines present. When we do see B lines we call this alveolar interstitial syndrome because it may represent something other than CHF or pulmonary edema. In particular it could be ARDS, it could be pulmonary contusion, although in most cases in the acute setting when someone presents with SOB and does have B lines, it will represent pulmonary edema most typically from congestive heart failure.