title: Usefulness of diffusion-weighted imaging for differentiating between desmoid tumors and malignant soft tissue tumors.
abstract: OBJECTIVE
  To evaluate the usefulness of diffusion-weighted imaging (DWI) for differentiating between desmoid tumors and malignant soft tissue tumors.
  
  
  METHODS
  Conventional MRI and DWI were performed for 8 desmoid tumors and 74 malignant soft tissue tumors. DWI was obtained with a single-shot echo-planar imaging sequence using a 1.5 Tesla (T) MR imager. DW images were acquired with motion-probing gradient pulses applied along three directions (x, y, and z axes) with three b-factors (0, 500, and 1000 s/mm²). Two observers blinded to clinical information measured three regions of interest within the solid tumor and selected a minimum apparent diffusion coefficient () in each lesion. The mean ADC of desmoid tumors was calculated and compared with that of malignant soft tissue tumors using the Mann-Whitney U test.
  
  
  RESULTS
  The mean ADC of desmoid tumors and malignant soft tissue tumors was 1.36 ± 0.48 × 10⁻³ mm² /s and 0.88 ± 0.20 × 10⁻³ mm² /s (mean ± SD), respectively. The mean ADC of the desmoid tumors was significantly higher than that of malignant soft tissue tumors (P < 0.01).
  
  
  CONCLUSIONS
  DWI is considered to be useful for differentiating between desmoid tumors and malignant soft tissue tumors. In the future, further investigation in a large series is necessary.
authors.affiliation: Department of Orthopaedic and Neuromusculoskeletal Surgery, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan. okaokay5888@yahoo.co.jp
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Oka
authors.forename: Toshitake
authors.initials: T
authors.lastname: Yakushiji
authors.forename: Hiro
authors.initials: H
authors.lastname: Sato
authors.forename: Toru
authors.initials: T
authors.lastname: Fujimoto
authors.forename: Toshinori
authors.initials: T
authors.lastname: Hirai
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yamashita
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mizuta
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003937:Diagnosis, Differential; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D005260:Female; D018222:Desmoid Tumors / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012983:Soft Tissue Neoplasms / Q000473:pathology*; D055815:Young Adult