title: An intravoxel incoherent motion diffusion-weighted imaging study of prostate cancer.
abstract: OBJECTIVE
  The purpose of this study is to investigate whether the intravoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI) parameters are different between prostate cancer, benign prostatic hyperplasia (BPH), and healthy peripheral zone (PZ).
  
  
  METHODS
  Detailed diffusion measurements of 26 patients with histologically proven prostate cancer have been made in this retrospective study. Trace IVIM DWI was performed using 10 b values (0, 10, 20, 30, 50, 80, 100, 200, 400, and 1000 s/mm2). Biexponential fits were applied to diffusion decay curves to calculate molecular diffusion coefficient, perfusion-related diffusion coefficient, and perfusion fraction on the basis of the IVIM model. Decay curves were also fit with monoexponential decay functions, and a statistical comparison between mono- and biexponential fits was performed. Paired t tests were performed to evaluate the statistical significance of the parameters of IVIM DWI and apparent diffusion coefficient (ADC) between prostate cancer, BPH, and PZ.
  
  
  RESULTS
  The chi-square values of biexponential fits were smaller than those from monoexponential fits in all cases. Biexponential functions provided statistically improved fits over monoexponential functions in 81% of cases. The ADC, molecular diffusion coefficient, and perfusion fraction in prostate cancer were significantly lower than those found in the PZ; however, perfusion fractions in prostate cancer and BPH were not significantly different. There were no significant differences in the prostate cancer, BPH, and PZ for the perfusion-related diffusion coefficient, which had large SDs.
  
  
  CONCLUSIONS
  IVIM DWI parameters are significantly different between prostate cancer and PZ. IVIM DWI may offer additional information for tissue characterization in the prostate gland.
authors.affiliation: Department of Radiology, National Defense Medical College, 3-2 Namiki, Tokorozawa, Saitama 359-8513, Japan. hshinmo@ndmc.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Shinmoto
authors.forename: Chiharu
authors.initials: C
authors.lastname: Tamura
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Soga
authors.forename: Eisuke
authors.initials: E
authors.lastname: Shiomi
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Yoshihara
authors.forename: Tatsumi
authors.initials: T
authors.lastname: Kaji
authors.forename: Robert V
authors.initials: RV
authors.lastname: Mulkern
mesh_terms: D000368:Aged; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology; D011470:Prostatic Hyperplasia / Q000175:diagnosis / Q000473:pathology; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology