title: Small-bowel MRI in children and young adults with Crohn disease: retrospective head-to-head comparison of contrast-enhanced and diffusion-weighted MRI.
abstract: BACKGROUND
  Small-bowel MRI based on contrast-enhanced T1-weighted sequences has been challenged by diffusion-weighted imaging (DWI) for detection of inflammatory bowel lesions and complications in patients with Crohn disease.
  
  
  OBJECTIVE
  To evaluate free-breathing DWI, as compared to contrast-enhanced MRI, in children, adolescents and young adults with Crohn disease.
  
  
  METHODS
  This retrospective study included 33 children and young adults with Crohn disease ages 17 ± 3 years (mean ± standard deviation) and 27 matched controls who underwent small-bowel MRI with contrast-enhanced T1-weighted sequences and DWI at 1.5 T. The detectability of Crohn manifestations was determined. Concurrent colonoscopy as reference was available in two-thirds of the children with Crohn disease.
  
  
  RESULTS
  DWI and contrast-enhanced MRI correctly identified 32 and 31 patients, respectively. All 22 small-bowel lesions and all Crohn complications were detected. False-positive findings (two on DWI, one on contrast-enhanced MRI), compared to colonoscopy, were a result of large-bowel lumen collapse. Inflammatory wall thickening was comparable on DWI and contrast-enhanced MRI. DWI was superior to contrast-enhanced MRI for detection of lesions in 27% of the assessed bowel segments and equal to contrast-enhanced MRI in 71% of segments.
  
  
  CONCLUSIONS
  DWI facilitates fast, accurate and comprehensive workup in Crohn disease without the need for intravenous administration of contrast medium. Contrast-enhanced MRI is superior in terms of spatial resolution and multiplanar acquisition.
authors.affiliation: Institute of Radiology, Department of Paediatric Radiology, University Hospital Wuerzburg, Josef-Schneider-Straße 2, 97080, Wuerzburg, Germany. neubauer@roentgen.uni-wuerzburg.de
authors.forename: Henning
authors.initials: H
authors.lastname: Neubauer
authors.forename: Thomas
authors.initials: T
authors.lastname: Pabst
authors.forename: Anke
authors.initials: A
authors.lastname: Dick
authors.forename: Wolfram
authors.initials: W
authors.lastname: Machann
authors.forename: Laura
authors.initials: L
authors.lastname: Evangelista
authors.forename: Clemens
authors.initials: C
authors.lastname: Wirth
authors.forename: Herbert
authors.initials: H
authors.lastname: Köstler
authors.forename: Dietbert
authors.initials: D
authors.lastname: Hahn
authors.forename: Meinrad
authors.initials: M
authors.lastname: Beer
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D003113:Colonoscopy; D003287:Contrast Media; D003424:Crohn Disease / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007421:Intestine, Small / Q000473:pathology*; D008206:Lymphatic Diseases / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D003287:Contrast Media