Diagnosed on plain radiography of the chest
Mediastinal width >8cm is abnormal
Potential causes include:
AP projection (Mediastinal structures further away from imaging plate)
Thoracic aortic aneurysm
Aortic dissection/rupture
Mediastinal mass
AP projection (Mediastinal structures further away from imaging plate)
Thoracic aortic aneurysm
Aortic dissection/rupture
Mediastinal mass
Widened mediastinum
Neck mass
Chest wall pain
Right atrial enlargement
Pneumomediastinum
Hemoptysis
Tracheostomy obstruction
Paradoxical vocal fold motion