title: Magnetization transfer ratio for the assessment of perianal fistula activity in Crohn's disease.
abstract: OBJECTIVE
  Assessment of perianal fistulas is important to guide management of Crohn's disease (CD). Our objectives were to analyze the feasibility of magnetization transfer (MT) imaging to assess fistulas and to evaluate its contribution in assessing disease activity.
  
  
  METHODS
  During 15 months, all patients referred for perianal fistulas in CD underwent 3T-MRI including diffusion, T2/T1-weighted gadolinium-enhanced sequences and MT sequences (one with an off-resonance saturation pulse of 800 and one with 1200 Hz). We collected Van Assche score, fistula activity signs by analyzing T2, diffusion and contrast enhancement. We calculated MT ratio (MTR) with a ROI in the largest fistula.
  
  
  RESULTS
  Twenty-nine patients (mean 34.9 years, range 17-53) were included. Van Assche score was 11.7, range 4-21. In 22 patients, the fistula presented with a bright T2 and diffusion signal with contrast enhancement, and was characterized as active. Mean MTR was respectively 47.2 (range 12-68) and 34.3 (range 11-57) at 800 and 1200 Hz. MTR at 800 Hz was significantly lower in non-active (34, range 12-55) than in active fistulas (51, range 24-68) (p < 0.02).
  
  
  CONCLUSIONS
  MTR is feasible for the assessment of fistulas in CD and in the future could be used to help identify active and non-active fistulas.
  
  
  CONCLUSIONS
  • MTR is feasible for the assessment of perianal fistulas in CD. • MT allows quantitative imaging of perianal fistula activity in CD. • MTR could be used to help identify active and non-active fistulas in CD.
authors.affiliation: Department of Radiology, Rouen University Hospital-Charles Nicolle, 1 rue de Germont, F-76031, Rouen cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Pinson
authors.affiliation: Department of Radiology, Rouen University Hospital-Charles Nicolle, 1 rue de Germont, F-76031, Rouen cedex, France.
authors.forename: M
authors.initials: M
authors.lastname: Dolores
authors.affiliation: Department of Radiology, Rouen University Hospital-Charles Nicolle, 1 rue de Germont, F-76031, Rouen cedex, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Cruypeninck
authors.affiliation: Department of Radiology, Rouen University Hospital-Charles Nicolle, 1 rue de Germont, F-76031, Rouen cedex, France.
authors.forename: E
authors.initials: E
authors.lastname: Koning
authors.affiliation: Department of Radiology, Rouen University Hospital-Charles Nicolle, 1 rue de Germont, F-76031, Rouen cedex, France.
authors.forename: J N
authors.initials: JN
authors.lastname: Dacher
authors.affiliation: Department of Gastroenterology, Rouen University Hospital-Charles Nicolle, 1 rue de Germont, F-76031, Rouen cedex, France.
authors.forename: G
authors.initials: G
authors.lastname: Savoye
authors.affiliation: Department of Radiology, Rouen University Hospital-Charles Nicolle, 1 rue de Germont, F-76031, Rouen cedex, France. celine.savoye-collet@chu-rouen.fr.
authors.forename: C
authors.initials: C
authors.lastname: Savoye-Collet
mesh_terms: D000293:Adolescent; D000328:Adult; D003424:Crohn Disease / Q000150:complications* / Q000175:diagnosis; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012003:Rectal Fistula / Q000175:diagnosis* / Q000209:etiology; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Anal fistula; Anus disease/diagnosis; Crohn’s disease; Magnetic resonance imaging; Magnetization transfer contrast imaging