title: MR imaging of perianal fistulas in Crohn's disease: sensitivity and specificity of STIR sequences.
abstract: BACKGROUND
  Although some studies proved the role of STIR sequences in the evaluation of perianal fistulas in Crohn's Disease (CD), contrast medium is still injected in many institutions since there is not a validated reference MR protocol. Our purpose was to evaluate the role of the STIR sequence in the detection and characterization of perianal fistulae comparing it to the post-contrast T1 sequence and correlating it with rectal examination under anesthesia.
  
  
  METHODS
  We retrospectively reviewed all clinical records of 31 CD patients, suspected of having perianal fistulas, who had been submitted to an MR study before and after contrast medium injection and surgical exploration under anesthesia within the same month. Perianal fistulas were classified according to the Parks' criteria. Finally, comparison between STIR and post-contrast T1-weighted fat saturated sequences was done.
  
  
  RESULTS
  29 fistulas were detected in 25 patients who underwent an MR study. There was no significant difference between MR imaging and exploration under anesthesia. For the detection of perianal fistulas of any type, there was a perfect statistical agreement between gadolinium-enhanced and STIR sequences (kappa value = 1).
  
  
  CONCLUSIONS
  STIR sequences represent a valid alternative to the T1-weighted sequences acquired after the injection of contrast medium, allowing the identification of the primary fistula, any secondary ramification, and complications of the disease.
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lo Re
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Tudisca
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy. federicavernuccio@gmail.com.
authors.forename: Federica
authors.initials: F
authors.lastname: Vernuccio
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Dario
authors.initials: D
authors.lastname: Picone
authors.affiliation: Gastroenterology and Hepatology Section, Di.Bi.Mis., University of Palermo, Piazza Delle Cliniche 2, 90127, Palermo, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Cappello
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Agnello
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Galia
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Maria Cristina
authors.initials: MC
authors.lastname: Galfano
authors.affiliation: Department of Radiology, Galliera Hospital, Via Mura delle Capuccine 14, 16128, Genoa, Italy.
authors.forename: Ennio
authors.initials: E
authors.lastname: Biscaldi
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Sergio
authors.initials: S
authors.lastname: Salerno
authors.affiliation: Department of Radiology, Cardarelli Hospital, Naples, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Pinto
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Midiri
authors.affiliation: Radiology Section, DIBIMED. University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Lagalla
mesh_terms: D000328:Adult; D003424:Crohn Disease / Q000150:complications; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D012003:Rectal Fistula / Q000175:diagnosis* / Q000209:etiology; D012189:Retrospective Studies; D055815:Young Adult
keywords: Crohn’s Disease; Inflammatory bowel disease; Magnetic resonance imaging; STIR