Inflammatory bowel disease-the role of cross-sectional imaging techniques in the investigation of the small bowel.

Background: The diagnosis of inflammatory bowel disease (IBD) in children and adolescents is based on the integration of clinical, biological, endoscopic, histological and radiological data.

Methods: The most important part of the diagnosis is the histology, which is acquired by endoscopy. Imaging of the small bowel has changed in recent years, but the imaging goals are primarily to determine the extent of small bowel involvement, assess complications and define candidates for surgery. Imaging techniques are divided into conventional and cross-sectional ones.

Results: The spectrum of imaging findings of cross-sectional techniques is discussed, emphasising the advantages and limitations of each technique, acknowledging the specificities of the paediatric population. Cross-sectional techniques have advanced the ability to diagnose and monitor inflammatory disease of the small bowel.

Conclusion: MR enterography is the technique of choice in children with known IBD, for the investigation of the small bowel and the whole GI tract. US should be the first choice examination in children with suspected IBD, while CT should be reserved for cases in which MRI is contraindicated or in acute emergency situations when US is inadequate.

Teaching Points: • Cross-sectional imaging of the small bowel is essential in paediatric IBD. • Endoscopy is unable to assess extramural disease and examine the entire small bowel. • US should be the first choice examination in children with suspected IBD. • MR enterography is the technique of choice in children with known IBD. • There are still controversies regarding the prediction of disease activity or fibrosis.