Aspiration Lung Abscess
Whenever you see an inlet to outlet shadow in the mediastinum on right side, consider esophageal dilatation .
Inhomogeniety of Cardiac Density
Cardiac density should be uniform except in areas overlying vertebral and descending aorta. If the right half of cardiac shadow appears more dense, one of the considerations should be dilated esophagus.
Thickening of Tracheoesophageal Stripe
Thickening of tracheo-esophageal stripe should raise suspicion of esophageal disease.
One of the causes of air-fluid level in mediastinum is obstruction to esophagus. The location of air-fluid level is behind trachea and is easy to recognize it in the lateral view.