title: Grading Crohn disease activity with MRI: interobserver variability of MRI features, MRI scoring of severity, and correlation with Crohn disease endoscopic index of severity.
abstract: OBJECTIVE
  The purpose of this article is to assess the interobserver variability for scoring MRI features of Crohn disease activity and to correlate two MRI scoring systems to the Crohn disease endoscopic index of severity (CDEIS).
  
  
  METHODS
  Thirty-three consecutive patients with Crohn disease undergoing 3-T MRI examinations (T1-weighted with IV contrast medium administration and T2-weighted sequences) and ileocolonoscopy within 1 month were independently evaluated by four readers. Seventeen MRI features were recorded in 143 bowel segments and were used to calculate the MR index of activity and the Crohn disease MRI index (CDMI) score. Multirater analysis was performed for all features and scoring systems using intraclass correlation coefficient (icc) and kappa statistic. Scoring systems were compared with ileocolonoscopy with CDEIS using Spearman rank correlation.
  
  
  RESULTS
  Thirty patients (median age, 32 years; 21 women and nine men) were included. MRI features showed fair-to-good interobserver variability (intraclass correlation coefficient or kappa varied from 0.30 to 0.69). Wall thickness in millimeters, presence of edema, enhancement pattern, and length of the disease in each segment showed a good interobserver variability between all readers (icc = 0.69, κ = 0.66, κ = 0.62, and κ = 0.62, respectively). The MR index of activity and CDMI scores showed good reproducibility (icc = 0.74 and icc = 0.78, respectively) and moderate CDEIS correlation (r = 0.51 and r = 0.59, respectively).
  
  
  CONCLUSIONS
  The reproducibility of individual MRI features overall is fair to good, with good reproducibility for the most commonly used features. When combined into the MR index of activity and CDMI score, overall reproducibility is good. Both scores show moderate agreement with CDEIS.
authors.affiliation: 1 Department of Radiology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands.
authors.forename: Jeroen A W
authors.initials: JA
authors.lastname: Tielbeek
authors.forename: Jesica C
authors.initials: JC
authors.lastname: Makanyanga
authors.forename: Shandra
authors.initials: S
authors.lastname: Bipat
authors.forename: Doug A
authors.initials: DA
authors.lastname: Pendsé
authors.forename: C Yung
authors.initials: CY
authors.lastname: Nio
authors.forename: Frans M
authors.initials: FM
authors.lastname: Vos
authors.forename: Stuart A
authors.initials: SA
authors.lastname: Taylor
authors.forename: Jaap
authors.initials: J
authors.lastname: Stoker
mesh_terms: D000328:Adult; D000368:Aged; D003113:Colonoscopy; D003287:Contrast Media; D003424:Crohn Disease / Q000473:pathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D003287:Contrast Media