title: Apparent diffusion coefficient values in peripheral and transition zones of the prostate: comparison between normal and malignant prostatic tissues and correlation with histologic grade.
abstract: OBJECTIVE
  To investigate the utility of apparent diffusion coefficient (ADC) values for discriminating tumor in patients with prostate cancer from normal prostatic tissues in healthy adult men, and to identify correlations between ADC and histologic grade of prostate cancer.
  
  
  METHODS
  A total of 125 healthy male volunteers (mean age, 60 years; range, 50-86 years) and 90 prostate cancer patients (mean age, 71 years; range, 51-88 years) underwent diffusion-weighted imaging (DWI) of the prostate with a single-shot echo-planar imaging sequence using b-factors of 0 and 800 sec/mm2. ADC was measured from two locations in the peripheral zone (PZ) and two locations in the central gland (CG) in normal subjects, and tumor locations of PZ or transition zone (TZ) in patients with prostate cancer.
  
  
  RESULTS
  Mean ADC values of tumor regions in both PZ (1.02+/-0.25x10(-3) mm2/sec) and TZ (0.94+/-0.21x10(-3) mm2/sec) were significantly lower than those in the corresponding normal regions (1.80+/-0.27x10(-3) mm2/sec and 1.34+/-0.14x10(-3) mm2/sec, respectively) (P<0.0001 each). Furthermore, a significant negative correlation was identified between ADC in PZ cancer and tumor Gleason score (rho=-0.497, P<0.0001).
  
  
  CONCLUSIONS
  ADC values appear to provide acceptable diagnostic accuracy in both PZ and TZ.
authors.affiliation: Department of Radiology, Kawasaki Medical School, Okayama, Japan. ttamada@med.kawasaki-m.ac.jp
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tamada
authors.forename: Teruki
authors.initials: T
authors.lastname: Sone
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Jo
authors.forename: Shinya
authors.initials: S
authors.lastname: Toshimitsu
authors.forename: Takenori
authors.initials: T
authors.lastname: Yamashita
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.forename: Daigo
authors.initials: D
authors.lastname: Tanimoto
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ito
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000473:pathology*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic