Widened mediastinum


  • 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


  • Mediastinum is divided into superior and inferior compartments, the latter further subdivided into anterior, middle and posterior compartments.[1]
Anatomy and contents of the mediastinum[2]

Mediastinal Masses

  • Anterior
    • Retrosternal goiter
    • Thymoma
    • Germ-cell tumor
    • Lymphadenopathy (lymphoma)
  • Middle
    • Aortic arch aneurysm
    • Dilated pulmonary artery
    • Tracheal lesion
  • Posterior
    • Esophageal lesions
    • Hiatal hernia
    • Descending aortic aneurysm
    • Paraspinal abscess

See Also

External Links


  1. Whitten CR, Khan S, Munneke GJ, Grubnic S. A diagnostic approach to mediastinal abnormalities. Radiographics. 2007;27(3):657–671. doi:10.1148/rg.273065136.
  2. Faiz, O., & Moffat, D. (2002). Anatomy at a glance. Malden, MA: Blackwell Science.