Mediastinal widening

An abnormal increase in transverse mediastinal diameter on chest imaging (typically >6–8 cm on an upright PA radiograph).

Causes

• Aortic aneurysm/dissection/rupture

• Hemorrhage: Trauma, post-procedural, anticoagulation

• Mediastinal lymphadenopathy: Lymphoma, metastatic malignancy

• Mediastinal masses: Thymoma, thyroid goiter, germ cell tumors

• Mediastinitis

• Sarcoidosis

• Technical and positional causes

  • Anteroposterior (AP) projection magnification

  • Patient rotation

  • Poor inspiratory effort

  • Supine positioning

  • Obesity or body habitus affecting mediastinal appearance