Upper GI series (aka contrast radiography of the upper GI tract) is a series of x-rays used to examine the GI tract for abnormalities. CT enterography is CT used in combination w/ barium contrast.

• In combination w/ other plain x-rays, allows the imaging of parts of the upper GI tract (e.g. parynx, larynx, esophagus, stomach, and small intestine), such tahtt eh inside wall lining, size, shape, contour, and patency are visible to the examiner
• W/ fluoroscopy, it can visualize the functional movement of examined organs (e.g. swallowing, peristalsis, or sphincter closure)

• A contrast medium, usually a radiocontrast agent (e.g. barium sulfate mixed w/ water) is ingested or instilled into the GI tract
• X-rays are used to create radiographs of the regions of interest
• The barium enhances the visibility of the relevant parts of the GI tract by coating the inside wall of the tract and appearing white on the film
• To further enhance the quality of images, air or gas is sometimes introduced into the GI tract [in addition to barium], known as double-contrast imaging. The gas is referred to as the negative contrast medium

Depending on the organs to be examined, barium radiographs can be classified into:

• Barium swallow
• Barium meal
• Barium follow-through
• Enteroclysis