title: Added value of diffusion-weighted magnetic resonance imaging for the diagnosis of perianal fistula.
abstract: OBJECTIVE
  To evaluate the added value of diffusion-weighted (DWI) magnetic resonance imaging (MRI) by comparison with T2-weighted images alone in the diagnosis of perianal fistula.
  
  
  METHODS
  MRI examinations of 123 patients (97 men, 26 women; mean age, 41.9 years) with suspected perianal fistula were retrospectively evaluated by two radiologists. Fat-suppressed T2-weighted fast spin echo images, DWI (b values, 0 and 1000s/mm2) and fat-suppressed gadolinium chelate-enhanced T1-weighted images were evaluated for each patient by using a four-point scale. Confidence scores and sensitivities were calculated for T2-weighted images alone, the combination of DWI and T2-weighted images and the combination of gadolinium chelate-enhanced T1-weighted images and T2-weighted images. The combination of gadolinium chelate-enhanced and T2-weighted images was used as reference standard.
  
  
  RESULTS
  Perianal fistulas were present in 92/123 patients (74.8%). An almost perfect interobserver agreement was found for T2-weighted images (kappa=0.868), the combination of gadolinium chelate-enhanced T1-weighted images and T2-weighted images (kappa=0.96) and the combination of DWI and T2-weighted images (kappa=0.90). The confidence scores for the diagnosis of perianal fistula for the combination of gadolinium chelate-enhanced T1-weighted images and T2-weighted images were greater than those of T2-weighted images alone for observer 1 (P<0.001) and observer 2 (P=0.009). The confidence scores of the combination of DWI and T2-weighted images were greater than those of T2-weighted images alone for observer 1 (P<0.001) and observer 2 (P=0.032). Sensitivity and specificity of the combination of DWI and T2-weighted images were greater than those of T2-weighted images alone for both observers.
  
  
  CONCLUSIONS
  DWI has a significant added value compared to T2-weighted imaging alone in the diagnosis of perianal fistula.
authors.affiliation: Ankara Numune Education and Research Hospital, Clinic of Radiology, No: 5Altındağ, Ankara 06100, Turkey. Electronic address: mehtapcavusoglu2@gmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Cavusoglu
authors.affiliation: Ankara Numune Education and Research Hospital, Clinic of Radiology, No: 5Altındağ, Ankara 06100, Turkey. Electronic address: semraduran91@gmail.com.
authors.forename: S
authors.initials: S
authors.lastname: Duran
authors.affiliation: Ankara Numune Education and Research Hospital, Clinic of Radiology, No: 5Altındağ, Ankara 06100, Turkey. Electronic address: denizsciliz@gmail.com.
authors.forename: D
authors.initials: D
authors.lastname: Sözmen Cılız
authors.affiliation: Ankara Numune Education and Research Hospital, Clinic of Radiology, No: 5Altındağ, Ankara 06100, Turkey. Electronic address: gozdetufan@gmail.com.
authors.forename: G
authors.initials: G
authors.lastname: Tufan
authors.affiliation: Ankara Numune Education and Research Hospital, Clinic of Radiology, No: 5Altındağ, Ankara 06100, Turkey. Electronic address: gulhatip@yahoo.com.
authors.forename: H G
authors.initials: HG
authors.lastname: Hatipoglu Çetin
authors.affiliation: Ankara Numune Education and Research Hospital, Clinic of Radiology, No: 5Altındağ, Ankara 06100, Turkey. Electronic address: arzu.ozsoy@hotmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Ozsoy
authors.affiliation: Ankara Numune Education and Research Hospital, Clinic of Radiology, No: 5Altındağ, Ankara 06100, Turkey. Electronic address: bulentsakman@gmail.com.
authors.forename: B
authors.initials: B
authors.lastname: Sakman
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001003:Anal Canal / Q000000981:diagnostic imaging*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007412:Intestinal Fistula / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055815:Young Adult
keywords: Diffusion-weighted MR imaging; Magnetic resonance imaging; Perianal fistula; Perineum