title: Assessment of disease behavior in patients with Crohn's disease by MR enterography.
abstract: BACKGROUND
  Magnetic resonance imaging (MRI) of the bowel is an increasingly used modality to evaluate patients with Crohn's disease. The Montreal classification of the disease behavior is considered as an excellent prognostic and therapeutic parameter for these patients. In our study, we correlated the behavior assessment performed by a radiologist based on MRI with the surgeons' clinical assessment based on the assessment during abdominal surgery.
  
  
  METHODS
  We evaluated 76 patients with Crohn's disease, who underwent bowel resection and had an MRI within 4 weeks before surgery. Radiological behavior assessment was performed by 2 radiologists based on MRI. Behavior was classified into B1 (nonstricturing and nonpenetrating), B2, and B3 (penetrating) disease. Surgical assessment was done by the same surgeon, who performed all bowel resections, based on intraoperative findings and histologic results.
  
  
  RESULTS
  The surgical assessment identified 4 patients (5%) as B1, 16 patients (21%) as B2, and 56 patients (74%) as B3. In 97% (n = 74) of all patients, the intraoperative and radiological assessment were identical with interobserver agreement of 0.937. In one case, B2 was radiological considered as B1, and in another case, B3 was diagnosed as B2. The diagnosis of a stricture had the highest sensitivity of 96%, whereas the detection of inflammatory mass showed the lowest sensitivity of 81%. Abscesses had the lowest positive predictive value of 68% with a specificity of 88%. Best correlation was found for fistulae (0.895).
  
  
  CONCLUSIONS
  MRI represents an excellent imaging modality to correctly assess the Montreal classification-based disease behavior in patients scheduled for bowel resection with Crohn's disease.
authors.affiliation: Department of Radiology, University Medical Center Regensburg, Germany.
authors.forename: Gabriela
authors.initials: G
authors.lastname: Schill
authors.forename: Igors
authors.initials: I
authors.lastname: Iesalnieks
authors.forename: Michael
authors.initials: M
authors.lastname: Haimerl
authors.forename: René
authors.initials: R
authors.lastname: Müller-Wille
authors.forename: Lena-Marie
authors.initials: LM
authors.lastname: Dendl
authors.forename: Philipp
authors.initials: P
authors.lastname: Wiggermann
authors.forename: Stephan
authors.initials: S
authors.lastname: Schleder
authors.forename: Janine
authors.initials: J
authors.lastname: Rennert
authors.forename: Claudia
authors.initials: C
authors.lastname: Ott
authors.forename: Ayman
authors.initials: A
authors.lastname: Agha
authors.forename: Christian
authors.initials: C
authors.lastname: Stroszczynski
authors.forename: Andreas G
authors.initials: AG
authors.lastname: Schreyer
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000714:Anastomosis, Surgical; D003424:Crohn Disease / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007249:Inflammation / Q000000981:diagnostic imaging* / Q000209:etiology; D007422:Intestines / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011379:Prognosis; D011446:Prospective Studies; D011859:Radiography; D062606:Tertiary Care Centers; D055815:Young Adult