• Inflammatory bowel disease
• Crohn's disease
• MRI
• IBD clinical
• ulcerative colitis

Interest in the use of cross-sectional imaging for assessment of inflammatory bowel disease (IBD) is rapidly growing. Among the different available imaging techniques, MRI is experiencing the largest expansion as judged by the increasing number of publications and the number of units that recently implemented MRI for the study of abdominal inflammatory diseases. A very high soft tissue contrast, lack of ionising radiation, low incidence of adverse events related to the intravenous contrast employed and high diagnostic precision in the evaluation of luminal and extraluminal lesions justify this preference.1 2

Diffusion-weighted imaging (DWI) MR sequence is a functional imaging technique derived from the analysis of the displacement of tissue water molecules due to random thermally-driven motion over ultra-small distances (ie, Brownian motion of water molecules). By the acquisition of DWI, an apparent diffusion coefficient (ADC) map can be generated that provides quantitative information on diffusion. Restricted motion of tissue water molecules is depicted as high signal intensity on DWI sequences and has low ADC values.

DWI has been used mainly for the evaluation of central nervous system lesions, particularly acute ischaemic stroke, intracranial tumours and demyelinating disease.3 4 The main limitations for the use of DWI in the abdominopelvic area are the artefacts generated by respiratory movements. Recent technical improvements allow correction of motion artefacts and provide higher quality images of abdominal organs. At present, the main clinical application of DWI in the abdominopelvic area is the detection of …