Imaging Case of the Week 26

It is 3 am and you are about to see a 38 year old female patient brought in by paramedics with complaints of dyspnoea. Her vital signs are bit concerning; she is tachypnoeic with a respiratory rate of 30 and her O2 sats are 90 % in room air. As you begin talking to her, she says she wants to go home. You convince her to get a chest x-ray and she reluctantly agrees. Here is the PA chest x-ray. What can you see ?

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The chest x-ray shows left lower lobe collapse which gives rise to the double left heart border or the sail sign.

  • There is a triangular density behind the heart, silhouetting the medial aspect of left diaphragm.
  • The second left heart border is due to the edge of the collapsed lower lobe.
  • There is volume loss in the left hemithorax with elevation of the left hemidiaphragm and depression of the left main bronchus.

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Left lower lobe collapse can be easily missed if careful attention is not paid at the time of interpretation, especially in an underpenetrated film. Unfortunately, I do not have a lateral view for this patient.