title: Magnetic resonance colonography for fibrosis assessment in rats with chronic colitis.
abstract: BACKGROUND
  Magnetic resonance colonography (MRC) has been developed to assess inflammatory bowel diseases. We aimed to assess the feasibility of MRC in rats with TNBS-induced chronic colitis and to confront imaging results with fibrosis and stenosing features of the model.
  
  
  METHODS
  Chronic colitis was induced in 12 rats by weekly intra-rectal injection of increasing doses of TNBS for 6 weeks, while 8 control rats received the vehicle. At week 7, MRC was performed. Fibrosis scores were assessed and fibrosis mediators measured.
  
  
  RESULTS
  Chronic colitis was associated with significant body weight loss (p<0.0001) and higher colon weight/length compared to controls (p = 0.0004). Fibrosis mediators and histological scores were significantly higher in rats with TNBS than in controls: α-SMA expression (0.9 versus 0.61, p = 0.0311) and fibrosis score (p = 0.0308). Colon wall thickness was higher in rats with TNBS than in controls: maximal thickness (2.38 versus 0.74 mm, p<0.0001) and minimal thickness (1.33 versus 0.48 mm, p<0.0001). Wall signal intensity on T2w images was higher in rats with TNBS than in controls (9040 versus 6192, p = 0.0101) and correlated with fibrosis score (r = 0.5214; p = 0.04). Luminal narrowing was higher in rats with TNBS (50.08 versus 10.33%, p<0.0001) and correlated with α-SMA expression (r = 0.5618; p = 0.01). Stenosis was observed in 7/9 rats with TNBS and in no controls (p = 0.0053).
  
  
  CONCLUSIONS
  MRC is feasible and easily distinguishes rats with colitis from controls. MRC signs correlated with fibrosis parameters. MRC evaluation may be part of a new anti-fibrosis drug assessment in experimental models of chronic colitis.
authors.affiliation: INSERM UMR 1073, Institute for Biomedical Research, Rouen University, Rouen, France; Gastroenterology Department, Rouen University Hospital, Rouen, France.
authors.forename: Chloé
authors.initials: C
authors.lastname: Melchior
authors.affiliation: INSERM UMR 1073, Institute for Biomedical Research, Rouen University, Rouen, France.
authors.forename: Emilien
authors.initials: E
authors.lastname: Loeuillard
authors.affiliation: INSERM UMR 1073, Institute for Biomedical Research, Rouen University, Rouen, France.
authors.forename: Rachel
authors.initials: R
authors.lastname: Marion-Letellier
authors.affiliation: INSERM U644, Institute for Biomedical Research, Rouen University, Rouen, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Nicol
authors.affiliation: INSERM U644, Institute for Biomedical Research, Rouen University, Rouen, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Mulder
authors.affiliation: INSERM UMR 1073, Institute for Biomedical Research, Rouen University, Rouen, France.
authors.forename: Charlène
authors.initials: C
authors.lastname: Guerin
authors.affiliation: INSERM UMR 1073, Institute for Biomedical Research, Rouen University, Rouen, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Bôle-Feysot
authors.affiliation: Pathology Department, Rouen University Hospital, Rouen, France.
authors.forename: Moutaz
authors.initials: M
authors.lastname: Aziz
authors.affiliation: INSERM UMR 1073, Institute for Biomedical Research, Rouen University, Rouen, France; Nutrition Department, Rouen University Hospital, Rouen, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Déchelotte
authors.affiliation: Radiology Department, Rouen University Hospital, Rouen, France; QUANTIF-LITIS EA 4108, Rouen University, Rouen, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Vera
authors.affiliation: INSERM UMR 1073, Institute for Biomedical Research, Rouen University, Rouen, France; Gastroenterology Department, Rouen University Hospital, Rouen, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Savoye
authors.affiliation: Radiology Department, Rouen University Hospital, Rouen, France; QUANTIF-LITIS EA 4108, Rouen University, Rouen, France.
authors.forename: Céline
authors.initials: C
authors.lastname: Savoye-Collet
mesh_terms: D000818:Animals; D002908:Chronic Disease; D003092:Colitis / Q000139:chemically induced / Q000175:diagnosis* / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods*; D003251:Constriction, Pathologic; D005240:Feasibility Studies; D005355:Fibrosis; D008279:Magnetic Resonance Imaging; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014302:Trinitrobenzenesulfonic Acid / Q000009:adverse effects
chemical_list: D014302:Trinitrobenzenesulfonic Acid