Extrapleural air sign

Dr Henry Knipe and Dr M Venkatesh et al.

The extrapleural air sign is one of the many signs of pneumomediastinum, and was first described by Lillard and Allen in 1965. It is defined as the presence the air between the parietal pleura and the diaphragm. On a lateral projection the air forms a radiolucent pocket of air posterior to the dome of the hemidiaphragm. The reader should be aware that this term is not synonymous with the term extrapleural sign by itself. 

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Article information

rID: 25222
System: Chest
Section: Signs
Synonyms or Alternate Spellings:
  • Extrapleural air sign

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