[Radiological diagnostics of the small bowel]

The barium meal with plain X-ray films of the small intestine has for decades been the undisputed gold standard in imaging of the small intestine. More recently, X-rays and fluoroscopy with an overall accuracy of 73% have been replaced by multislice computed tomography (MSCT) or modern magnetic resonance imaging (MRI). Ultrasound is suitable for the orienting investigation of the small intestine in the context of general abdominal sonography as well as for dedicated examinations with a sensitivity of 67-96% and a specificity up to 97%. The endoscopic examinations of the small bowel, such as video capsule endoscopy and double-balloon enteroscopy are expensive and time-consuming techniques, which provide valuable information in special indications. Other than with the stomach or colon, the diagnostics of primary small intestine tumors plays a relatively subordinate role due to the low incidence of 3-5% of all gastrointestinal (GI) neoplasms but with a high sensitivity of 84% and a specificity of up to 97% for computed tomography (CT) and MRI. Predominant questions are those concerning ileus or the diagnostics of passage disturbances after preceding operations, to depict bowel obstructions, adhesions or the involvement of the small bowel in peritoneal carcinomatosis. The sensitivity per lesion in the initial evaluation of Crohn's disease (CD) is 47-68% for capsule endoscopy, 43% for MRI and 21% for CT enterography. In cases of known CD, the sensitivity is 70% for capsule endoscopy and 79% for MRI. A further indication is the evaluation of acute or occult gastrointestinal bleeding.