Pneumomediastinum (summary)

Last revised by Jeremy Jones on 24 May 2018
This is a basic article for medical students and other non-radiologists

Pneumomediastinum describes air/gas within the mediastinum and is readily demonstrated on CT and may be seen on a chest radiograph.

Reference article

This is a summary article; read more in our article on pneumomediastinum.


  • pathophysiology
    • gas within the mediastinum
    • causes
      • tracheobronchial perforation with gas tracking
      • perforation of esophagus
      • penetrating trauma

Radiographic features

Chest radiograph
  • gas outlines the mediastinal structures
  • may be difficult to see on a chest x-ray
CT chest
  • much more readily demonstrated on a CT

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Cases and figures

  • Case 1: pneumomediastinum
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  • Case 2: pneumomediastinum and subcutanous emphysema
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  • Case 3: pneumomediastinum on CT
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