Findings beyond Crohn's disease encountered on magnetic resonance enterography: a pictorial review of diseases inside and outside the bowel.

1Department of Radiology, Sengkang General Hospital, Singapore, 2Department of Radiology, Ninewells Hospital, Dundee, United Kingdom Correspondence: Dr Yeap Phey Ming, Consultant Radiologist, Department of Radiology, Sengkang General Hospital, 110 Sengkang East Way, Singapore 544886. yeap.phey.ming@singhealth.com.sg INTRODUCTION Cross-sectional imaging of the small bowel is replacing conventional barium studies in many centres, with magnetic resonance (MR) enterography becoming particularly popular for the assessment of small bowel Crohn’s disease, given its superior tissue contrast with improved visualisation of the entire bowel and lack of ionising radiation. In addition, MR enterography provides functional information on the peristalsis and distensibility of the involved small bowel segment with dynamic sequences, which is an advantage over computed tomography (CT). Over 15 years of performing MR enterography examinations, we have encountered a variety of clinically significant findings that mimic or are associated with Crohn’s disease, where the initial clinical suspicion was for Crohn’s disease. As a experience with MR enterography increases, there is also increasing clinician confidence in MR enterography, which has led to referral for evaluation of small bowel diseases other than Crohn’s disease.(1) The manifestations of Crohn’s disease on MR enterography have been well described, but there is comparatively little in the literature about MR enterography appearances of diseases that can mimic Crohn’s disease or diseases other than Crohn’s disease.(2) In this pictorial essay, we present a range of enteric and extra-enteric diseases that mimic or are associated with Crohn’s disease, and provide examples of imaging features. In addition, we review the use of MR enterography for the evaluation of small bowel diseases other than Crohn’s disease. Our aim is to raise awareness of the range of diseases that may be encountered on MR enterography, and to add to the limited literature on findings unrelated to Crohn’s disease.