Critical chest radiographs

Tension pneumothorax 

A tension pneumothorax develops when injury creates a one way valve for the air to enter but not to leave, the pleural space. 

Clinical features are contralateral tracheal deviation, ipsilateral hyperresonance to percussion, ipsilateral decreased breath sounds, distended neck veins and hypoperfussion.

The typical radiographic findings are ipsilateral lung collapse  (white arrow) with widened interescostal  spaces and contralateral mediastinal deviation  (red arrow). 

With a left hemithoax, the left hemidiafragm, may be depressed, but the liver prevent this to developing on the right side.