Continuous diaphragm sign
ChestRadiograph
The entire diaphragm, including its central portion behind the heart, is outlined as a continuous line by lucency above it.
What it means
Pneumomediastinum, with air tracking between the heart and diaphragm.
Mechanism
Mediastinal air interposes between the pericardium and the central tendon of the diaphragm, making the normally hidden central diaphragm visible.
Associated conditions
- Pneumomediastinum
- Oesophageal rupture (Boerhaave)
- Asthma or Valsalva-related air leak
- Blunt or iatrogenic airway injury
Pearls
- Normally the central diaphragm is obscured by the cardiac silhouette; visibility implies air.
- Search for other pneumomediastinum signs such as the ring-around-the-artery sign.
References
- Radiopaedia: Continuous diaphragm sign
For educational use only. This dictionary is a study aid and reference, not a diagnostic tool, and must not be used to guide clinical decisions or patient care. Imaging appearances vary; always correlate with the full clinical picture and confirm with a qualified radiologist.