5. Stomach and duodenum upper GI series, PA erect projection

This is from a different study than the one used for Image #4. Here the UGI was performed using a single contrast technique, i.e., the patient drank barium sulfate of a lesser density and greater volume than that used for the double contrast study. The barium distends the lumen of the GI tract, creating a radiopaque cast of it and allowing its contours to be evaluated.

The patient must have been positioned erect (standing) for this image; note the straight line interface between the air in the fundus and the barium in the rest of the stomach. This is called an air-fluid level, and will always be oriented parallel to the floor. Such an interface can only be visualized tangentially like this when the x-ray beam is also oriented parallel to the floor (i.e., horizontally). The only way to visualize an air-fluid level in the transverse/horizontal plane in any structure is to have the patient positioned erect.

The feathery appearance of the duodenum and jejunum is typical for these segments on a single contrast study, and is due to their numerous mucosal folds. The "C" shape of the duodenum is well demonstrated here.