title: Diffusion-Weighted MR Enterography to Monitor Bowel Inflammation after Medical Therapy in Crohn's Disease: A Prospective Longitudinal Study.
abstract: To prospectively evaluate the performance of diffusion-weighted imaging (DWI) to monitor bowel inflammation after medical therapy for Crohn's disease (CD).
  
  
  
  Before and following 1-2 years of medical therapy, between October 2012 and May 2015, 18 randomly selected adult CD patients (male:female, 13:5; mean age ± SD, 25.8 ± 7.9 years at the time of enrollment) prospectively underwent MR enterography (MRE) including DWI (b = 900 s/mm2) and ileocolonoscopy. Thirty-seven prospectively defined index lesions (one contiguous endoscopy-confirmed inflamed area chosen from each inflamed anatomical bowel segment; 1-4 index lesions per patient; median, 2 lesions) were assessed on pre- and post-treatment MRE and endoscopy. Visual assessment of treatment responses on DWI in 4 categories including complete remission and reduced, unchanged or increased inflammation, and measurements of changes in apparent diffusion coefficient (ΔADC), i.e., pre-treatment-post-treatment, were performed by 2 independent readers. Endoscopic findings and CD MRI activity index (CDMI) obtained using conventional MRE served as reference standards.
  
  
  
  ΔADC significantly differed between improved (i.e., complete remission and reduced inflammation) and unimproved (i.e., unchanged or increased inflammation) lesions: mean ± SD (× 10-3mm2/s) of -0.65 ± 0.58 vs. 0.06 ± 0.15 for reader 1 (p= 0.022) and -0.68 ± 0.56 vs. 0.10 ± 0.26 for reader 2 (p= 0.025). DWI accuracy for diagnosing complete remission or improved inflammation ranged from 76% (28/37) to 84% (31/37). A significant negative correlation was noted between ΔADC and ΔCDMI for both readers with correlation coefficients of -0.438 and -0.461, respectively (p< 0.05).
  
  
  
  DWI is potentially a feasible tool to monitor quantitatively and qualitatively bowel inflammation of CD after medical treatment.
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Jimi
authors.initials: J
authors.lastname: Huh
authors.affiliation: Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Kyung Jo
authors.initials: KJ
authors.lastname: Kim
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Seong Ho
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: So Hyun
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Suk-Kyun
authors.initials: SK
authors.lastname: Yang
authors.affiliation: Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Byong Duk
authors.initials: BD
authors.lastname: Ye
authors.affiliation: Department of Gastroenterology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Sang Hyoung
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Radiology and Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul 03722, Korea.
authors.forename: Kyunghwa
authors.initials: K
authors.lastname: Han
authors.affiliation: Department of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul 05505, Korea.
authors.forename: Ah Young
authors.initials: AY
authors.lastname: Kim
mesh_terms: D000293:Adolescent; D000328:Adult; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D003424:Crohn Disease / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D016099:Endoscopy, Gastrointestinal; D005260:Female; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007249:Inflammation / Q000000981:diagnostic imaging / Q000473:pathology; D000069285:Infliximab / Q000627:therapeutic use; D007420:Intestine, Large / Q000000981:diagnostic imaging / Q000473:pathology; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D007166:Immunosuppressive Agents; D000069285:Infliximab
keywords: Crohn; Crohn's; Diffusion; Diffusion-weighted; Follow-up; Longitudinal; Magnetic resonance; Magnetic resonance enterography; Monitoring