title: Magnetic resonance colonography in rats with TNBS-induced colitis: a feasibility and validation study.
abstract: BACKGROUND
  Magnetic resonance colonography (MRC) has been recently developed to assess bowel inflammation in inflammatory bowel disease (IBD) patients. Evaluating animal models of inflammation with MRC may be important in new drug-screening processes. The aim of this study was to assess the feasibility of MRC in colitic rats and confront it with model characteristics.
  
  
  METHODS
  Colitis was induced by rectal injection of trinitrobenzene-sulfonic acid (TNBS) in 13 rats while six rats received the vehicle. MRC was performed at day 2. Colon inflammation and production of inflammatory mediators were evaluated. Image quality was assessed by wall and motion artifacts. MRC criteria were bowel wall thickness, wall signal intensity on T2-weighted (T2w) and T1w images, the appearance of a target sign pattern, and irregular patterns of mucosal surface.
  
  
  RESULTS
  MRC quality was good or excellent in 16/21 examinations with no difference between groups. Colitis rats were significantly different from controls in terms of wall thickness (P = 0.004), the appearance of a target sign pattern (P = 0.02), irregular patterns of mucosal surface (P = 0.01), and hyperintensity on T1w images (P = 0.03). All MRC criteria except maximal bowel wall thickness were associated with colon weight:length ratio and inflammatory biomarkers (all P < 0.05). Minimal bowel wall thickness and wall signal intensity on T2w images were associated with histological score (P < 0.05).
  
  
  CONCLUSIONS
  MRC is feasible and reliable in rats with TNBS-induced colitis. MRC criteria including colon wall thickness, wall signal intensity on T2w images, hyperintensity in T1w sequence, and the appearance of a target sign pattern may be potential targets for new IBD drugs.
authors.affiliation: INSERM Unit U1073, Institute for Biomedical Research, Rouen University, Rouen, France.
authors.forename: Cloé
authors.initials: C
authors.lastname: Charpentier
authors.forename: Rachel
authors.initials: R
authors.lastname: Marion-Letellier
authors.forename: Guillaume
authors.initials: G
authors.lastname: Savoye
authors.forename: Lionel
authors.initials: L
authors.lastname: Nicol
authors.forename: Paul
authors.initials: P
authors.lastname: Mulder
authors.forename: Moutaz
authors.initials: M
authors.lastname: Aziz
authors.forename: Pierre
authors.initials: P
authors.lastname: Vera
authors.forename: Pierre
authors.initials: P
authors.lastname: Déchelotte
authors.forename: Céline
authors.initials: C
authors.lastname: Savoye-Collet
mesh_terms: D000818:Animals; D015153:Blotting, Western; D003092:Colitis / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D003113:Colonoscopy; D051546:Cyclooxygenase 2 / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D004195:Disease Models, Animal; D005240:Feasibility Studies; D018836:Inflammation Mediators / Q000378:metabolism; D007413:Intestinal Mucosa / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D052247:Nitric Oxide Synthase Type II / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D014302:Trinitrobenzenesulfonic Acid / Q000633:toxicity*
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D014302:Trinitrobenzenesulfonic Acid; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2