This is a case of a 73 year old who ate fish for dinner and felt she swallowed a bone.  The "chocking" sensation did not clear and even worsened as the night progresses.  She had no history of neck trauma.. 

On lateral X-Ray three abnormalities were found:

The air was felt to represent a perforation caused by the fish bone.  Emergency endoscopy was performed, with great care given to the neck.

The fish bone was removed with an endoscope, but the patient did not have a perforation, but instead had a Zenker's Diverticulum.  The diverticulum is shown in a post-operative barium swallow as a large pouch like accumulation of barium in the neck.