title: MR Enterography Assessment of Bowel Inflammation Severity in Crohn Disease Using the MR Index of Activity Score: Modifying Roles of DWI and Effects of Contrast Phases.
abstract: OBJECTIVE
  The purpose of this article is to appraise the use of the MR index of activity (MaRIA) score in evaluating Crohn disease (CD) on present-day MR enterography images, with an emphasis on determining the modifying roles of DWI and the effects of different contrast enhancement phases.
  
  
  METHODS
  Fifty patients prospectively underwent MR enterography, including DWI and enteric and portal phase scans, and ileocolonoscopy with segmental CD endoscopic index of severity (CDEIS) scoring within a week. Thirty-nine terminal ilea and 40 right-sided colons (mean [± SD] segmental CDEIS score, 14.3 ± 12.1) from 42 patients with CD (mean age, 27 ± 6.2 years) were finally analyzed by three independent readers. Original and modified (ulcer replaced with DWI grade) MaRIA scores were compared regarding their correlation with segmental CDEIS score, accuracy in diagnosing active (segmental CDEIS score ≥ 3) and severe (segmental CDEIS score ≥ 12) inflammation, and interobserver reproducibility. The primary analysis used portal phase data, and the agreement between portal and enteric phase scores was analyzed.
  
  
  RESULTS
  MaRIA and modified MaRIA scores correlated similarly with CDEIS scores (r = 0.737 and 0.742; p = 0.387) and did not significantly differ in terms of AUC values for the diagnosis of active (0.909 and 0.903; p = 0.571) or severe (0.907 and 0.892; p = 0.443) inflammation. The intraclass correlation coefficient was significantly higher for modified MaRIA than for MaRIA (0.845 and 0.701; p < 0.001). The mean difference between portal and enteric phase scores (i.e., portal minus enteric) was 0.33-0.36 score points for individual readers, and the Bland-Altman repeatability coefficient was 0.9-1.42 score points.
  
  
  CONCLUSIONS
  Interobserver reproducibility in evaluating the severity of bowel inflammation in CD using the MaRIA score can be improved by modification with DWI. MaRIA scoring provides steady results across enteric and portal phases.
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, South Korea.
authors.forename: Jin Sil
authors.initials: JS
authors.lastname: Kim
authors.affiliation: 2 Department of Radiology, Konyang University College of Medicine, Konyang University Hospital, Daejeon, South Korea.
authors.forename: Hye Young
authors.initials: HY
authors.lastname: Jang
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, South Korea.
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Park
authors.affiliation: 3 Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Kyung-Jo
authors.initials: KJ
authors.lastname: Kim
authors.affiliation: 4 Department of Radiology, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul, South Korea.
authors.forename: Kyunghwa
authors.initials: K
authors.lastname: Han
authors.affiliation: 3 Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Suk-Kyun
authors.initials: SK
authors.lastname: Yang
authors.affiliation: 3 Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Byong Duk
authors.initials: BD
authors.lastname: Ye
authors.affiliation: 3 Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, South Korea.
authors.forename: Sang Hyoung
authors.initials: SH
authors.lastname: Park
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, South Korea.
authors.forename: Jong Seok
authors.initials: JS
authors.lastname: Lee
authors.affiliation: 1 Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, South Korea.
authors.forename: Hyun Jin
authors.initials: HJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D003113:Colonoscopy; D003287:Contrast Media; D003424:Crohn Disease / Q000000981:diagnostic imaging* / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007249:Inflammation; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results; D012720:Severity of Illness Index
chemical_list: D003287:Contrast Media
keywords: Crohn disease; MR enterography; diffusion; score; severity