is a mediastinum
with a measured width greater than 8 cm on PA chest X-ray
A widened mediastinum can be indicative of several important pathologies, such as aortic aneurysm
and hilar lymphadenopathy
This is also a classic finding associated with inhalational anthrax. A widened mediastinum was found in 7 of the first 10 victims infected by anthrax (Bacillus anthracis) in 2001.
Widened mediastinum is also found in patients with esophageal rupture, mediastinal mass, or pericardial effusion.