title: A comparison of endoscopic ultrasound, magnetic resonance imaging, and exam under anesthesia for evaluation of Crohn's perianal fistulas.
abstract: OBJECTIVE
  To determine accuracy of endoscopic ultrasound (EUS) and magnetic resonance imaging (MRI) for evaluation of Crohn's disease perianal fistulas.
  
  
  METHODS
  Thirty-four patients with suspected Crohn's disease perianal fistulas were prospectively enrolled in a blinded study comparing EUS, MRI, and examination under anesthesia (EUA). Fistulas were classified according to Parks' criteria, and a consensus gold standard was determined for each patient. Acceptable accuracy was defined as agreement with the consensus gold standard for > or =85% of patients.
  
  
  RESULTS
  Three patients did not undergo MRI; 1 did not undergo EUS or EUA; and consensus could not be reached for 1. Thirty-two patients had 39 fistulas (20 trans-sphincteric, 5 extra-sphincteric, 6 recto-vaginal, 8 others) and 13 abscesses. The accuracy of all 3 modalities was > or =85%: EUS 29 of 32 (91%, confidence interval [CI] 75%-98%), MRI 26 of 30 (87%, CI 69%-96%), and EUA 29 of 32 (91%, CI 75%-98%). Accuracy was 100% when any 2 tests were combined.
  
  
  CONCLUSIONS
  EUS, MRI, and EUA are accurate tests for determining fistula anatomy in patients with perianal Crohn's disease. The optimal approach may be combining any 2 of the 3 methods.
authors.affiliation: The Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: D A
authors.initials: DA
authors.lastname: Schwartz
authors.forename: M J
authors.initials: MJ
authors.lastname: Wiersema
authors.forename: K M
authors.initials: KM
authors.lastname: Dudiak
authors.forename: J G
authors.initials: JG
authors.lastname: Fletcher
authors.forename: J E
authors.initials: JE
authors.lastname: Clain
authors.forename: W J
authors.initials: WJ
authors.lastname: Tremaine
authors.forename: A R
authors.initials: AR
authors.lastname: Zinsmeister
authors.forename: I D
authors.initials: ID
authors.lastname: Norton
authors.forename: L A
authors.initials: LA
authors.lastname: Boardman
authors.forename: R M
authors.initials: RM
authors.lastname: Devine
authors.forename: B G
authors.initials: BG
authors.lastname: Wolff
authors.forename: T M
authors.initials: TM
authors.lastname: Young-Fadok
authors.forename: N N
authors.initials: NN
authors.lastname: Diehl
authors.forename: J H
authors.initials: JH
authors.lastname: Pemberton
authors.forename: W J
authors.initials: WJ
authors.lastname: Sandborn
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000758:Anesthesia; D003424:Crohn Disease / Q000175:diagnosis* / Q000601:surgery; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000473:pathology; D011446:Prospective Studies; D012003:Rectal Fistula / Q000175:diagnosis* / Q000601:surgery; D012007:Rectum / Q000000981:diagnostic imaging; D014463:Ultrasonography