Barium Swallow vs Upper GI Series
What is Upper Gastrointestinal (GI) Tract Radiography?
Also called an upper gastrointestinal (GI) series or simply an upper GI, upper gastrointestinal tract radiography is an x-ray examination of the esophagus, stomach and first part of the small intestine. However, in order for the anatomy to show up on radiographic images, the upper gastrointestinal tract must be coated or filled with a contrast material called barium, an element that appears bright white on radiographs. The barium is given to the patient to drink. This procedure is called upper gastrointestinal tract radiography when the esophagus, stomach, and duodenum are evaluated, or a barium swallow when only the pharynx and esophagus are evaluated. Additionally, some patients are asked to swallow baking-soda crystals to create gas and further improve the images; this procedure has the modified name of air-contrast or double-contrast upper GI.
source: http://www.fmh.org/body.cfm?id=181
