How do doctors determine if there is a partial rupture to the esophagus?

Swallow contrast: Rupture of the esophagus is serious and requires definitive diagnosis and treatment to avoid injury and possible death. Diagnosis is generally made by swallowing a water soluble contrast, followed by x-rays to see if the contrast leaks out of the esophagus. Also, the x-ray may show air in the lung space (pneumothorax) or in the middle of the chest (mediastinum). Treatment is surgical or stent.