Gastrointestinal tract

Because the gastrointestinal tract is not visualised with routine radiographic techniques, contrast media, which are opaque to radiation, must be added in some way. Imaging of the oesophagus, ventricle and duodenum (upper gastrointestinal tract) has to be done with oral contrast media (barium) and conventional or digital X-ray technique. These examinations are done mainly to detect or rule out ulcerations and malignant diseases. Imaging of the large bowel is done with a barium enema. Barium, which will cover the mucosal lining, is often supplemented with air insufflation. This technique results in a moderate distension of the organ and thus allows a very detailed and precise imaging of both normal and pathological structures.

Alternative investigations of both upper and lower GI tract are done with endoscopic fiberoptic devices. CT can be of some use in validating both upper and lower GI tract. Ordinary sonography has a very limited use and MRI is not indicated with today's technique. NM is used to measure gastric emptying rate and diagnose gastro-oesophageal reflux and oesophagus motility disorders.