title: Diffusion-weighted MRI: role in detecting abdominopelvic internal fistulas and sinus tracts.
abstract: OBJECTIVE
  To retrospectively determine the incremental value of diffusion-weighted MR-imaging (DW-MRI) to T2-weighted (T2w) images in diagnosis of internal fistulas (IFs) and sinus tracts (STs).
  
  
  METHODS
  Fourteen patients with 25 IFs and STs arising from the small bowel (20), colon (4) and biliary tract (1) were included. Two independent observers reviewed T2w images, T2w+DW-MRI images and T2w+contrast enhanced T1-weighted (CE T1w) images at three sessions to detect IF/ST based on a confidence scale of five. Sensitivity and confidence score of each session was compared.
  
  
  RESULTS
  10/25 (40%) and 9/25 (36%) IFs and STs were detected on T2w images by observer 1 and 2, respectively. Both observers detected 19/25 (76%) and 24/25(96%) IFs and STs on T2w+DW-MRI and T2w+CE T1w images, respectively. Detection rate and confidence score improved significantly by combining T2w images with DW-MRI or CE T1w images (reader 1 + 2: P ≤ 0.01). There was no significant difference between the IF/ST detection rate of T2w+DW-MRI and T2w+CE T1 image combinations. Confidence scores with T2w+CE T1w images were significantly greater than DW-MRI+T2w images (reader 1:P = 0.01; reader 2: P = 0.03).
  
  
  CONCLUSIONS
  DW-MRI showed additional value to T2w imaging for diagnosis of IF and ST. DW-MRI can be a useful adjunct, especially for patients with renal failure.
authors.affiliation: The University of Chicago, Department of Radiology, Chicago, Illinois 60637, USA. christine.schmid-tannwald@med.uni-muenchen.de
authors.forename: Christine
authors.initials: C
authors.lastname: Schmid-Tannwald
authors.forename: Garima
authors.initials: G
authors.lastname: Agrawal
authors.forename: Farid
authors.initials: F
authors.lastname: Dahi
authors.forename: Ila
authors.initials: I
authors.lastname: Sethi
authors.forename: Aytekin
authors.initials: A
authors.lastname: Oto
mesh_terms: D000005:Abdomen / Q000473:pathology; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003287:Contrast Media / Q000494:pharmacology; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D005402:Fistula / Q000175:diagnosis*; D006801:Humans; D007412:Intestinal Fistula / Q000473:pathology; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D003287:Contrast Media