Ultrasound Level 1 Tutorial: Lung Ultrasound
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Tutorial: Lung Ultrasound
Learn ultrasound of the lung. Identify pneumothorax, pleural effusions and wet lungs.
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Tutorial: Lung Ultrasound Interstitial Lung Patterns
Times Practiced
Cases Completed
1h 24m
Total Time spent
1m 24s
Average Time
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

1 Adapted from: Soni, SJ, (2014). 'Chapter 9: Lung Ultrasound Interpretation'. In: (ed), Point-of-Care Ultrasound. 1st ed. Canada: Saunders. pp.66-67