The differential diagnoses for mediastinal widening include:
- traumatic aortic injury
- vascular anomalies
- pneumomediastinum
- lung
- atelectasis
- pulmonary masses abutting the mediastinum
- mediastinal lymphadenopathy
- enlarged pulmonary arteries
- mediastinal lipomatosis
- masses
- thymus
- diaphragmatic hernia
- technical factors (on chest x-ray)
- rotation
- poor inspiration
- supine position
- lordotic position