MR enterography of ileocolovesicular fistula in pediatric Crohn disease.

Crohn disease, a form of chronic inflammatory bowel disease is characterized by discontinuous inflammatory lesions of the gastrointestinal tract, has a variety of behavioral patterns, including penetrating or fistulous disease. While magnetic resonance enterography (MRE) excellently depicts inflamed bowel segments, it can also be used to assess for a variety of Crohn-disease-related extraintestinal complications, including fistulae. We present the MRE findings of a complex ileocolovesicular fistula in a 14-year-old boy with Crohn disease, where the fistulous tract to the urinary bladder was best delineated on precontrast T1-W imaging because of the presence of fecal material.