Interstitial Lung Patterns
Interstitial Lung Patterns
So far we have studied the following features of lung ultrasound:- lung sliding
- A lines
- B lines
- comet tails
Memorize the following facts:- lung sliding is absent if there is:
- a pneumothorax
- no lung movement (stuck to chest wall or severely consolidated)
- A lines are:
- normal
- present in pneumothorax
- B lines are:
- abnormal
- absent with pneumothorax
- B lines will obliterate A lines
- B lines are caused by a "wet" visceral pleura due to:
- imflammation (pneumonia, ARDS, pneuminitis)
- CHF
- couple other "lung" processes
Combining these findings and applying some logical thinking, we can create some diagnostic shortcuts1:
Profile #1- both lungs show lung sliding, A lines, comet tails, and no B lines
- this is a normal pattern
- diseases that could show this pattern include COPD, asthma and pulmonary emobolism
- this is called the A profile
Profile #2- one lung shows normal pattern
- one lung shows no lung sliding, A lines, no comet tails, no lung pulse and no B lines
- this is unilateral pneumothorax
- this is called the A' profile
Profile #3- both lungs show lung sliding, no A lines, no comet tails, and B lines
- note that this is bilateral
- this could be CHF, ARDS, or any bilateral inflammatory or infective process
- less common cause includes pulmonary fibrosis
- this is called the B profile
Profile #4- both lungs show no lung sliding and B lines
- this is severe bilateral pneumonia
- lung sliding is absent due to severe consolidation and no air in that lung
- this is called B' profile
Profile #5- one lung shows lung sliding, A lines, comet tails, and no B lines
- other lung shows lung sliding with B lines
- this is consistent with a unilateral process such as pneumonia
- this is called AB profile
References:
1 Adapted from: Soni, SJ, (2014). 'Chapter 9: Lung Ultrasound Interpretation'. In: (ed), Point-of-Care Ultrasound. 1st ed. Canada: Saunders. pp.66-67
