Magnetic resonance imaging of small bowel Crohn's disease

Crohn's disease (CD) is a chronic relapsing inflammatory disease of the gastrointestinal tract, which mostly affects young patients. Imaging techniques form a very important part for the evaluation of CD and for monitoring disease progression or response to therapy. Currently, imaging of CD is increasingly being performed by cross-sectional modalities, i.e. multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI), since these techniques allow for simultaneous visualization of luminal, mural and extraintestinal disease extension. MR enterography has the potential to safely and noninvasively accomplish the imaging needs of patients with Crohn disease without exposing them to ionizing radiation. The new imaging paradigm should contemplate patient safety as a very important aspect when assessing the role of an imaging modality in comparison with others. For this reason, MRI may be the preferred modality for evaluation of small bowel disease, especially in young patients in the setting of CD, considering that the majority will undergo frequent repeat studies. Also, the information on disease activity is not matched by any other imaging method. In this review article, the authors discuss the essential aspects of MR evaluation of CD, including protocol and imaging findings, also referring the advantages over other radiological studies, concerning safety, accuracy and potential importance for therapeutic approach.