title: Ultra-high b-value diffusion-weighted MRI for the detection of prostate cancer with 3-T MRI.
abstract: OBJECTIVE
  To determine, with histopathological findings of radical prostatectomy as reference, whether diffusion-weighted imaging (DWI) using b = 2000 s/mm(2) for 3-T magnetic resonance imaging (MRI) is superior to the use of b = 1000 s/mm(2) for prostate cancer detection.
  
  
  METHODS
  This study evaluated 73 patients with biopsy-proven prostate cancer. All patients underwent preoperative 3-T MRI using T2-weighted imaging (T2WI) and DWI (b = 0, 1000, 2000 s/mm(2) ). The following three sets of images were evaluated separately by two radiologists: protocol A (T2WI alone), protocol B (T2WI and DWI with b = 1000 s/mm(2) ), and protocol C (T2WI and DWI with b = 2000 s/mm(2) ). For estimation of diagnostic capability, area under the receiver operating characteristic (ROC) curve (AUC) was calculated.
  
  
  RESULTS
  A total of 341 cancer foci were found in the prostectomy specimens of 73 patients. Reader 1 rated AUCs of the three sets as; A 0.66, B 0.77, C 0.80. ROC analysis showed significant differences among the three protocols (A vs. B vs. C: P < 0.0001, A vs. B: P < 0.0001, B vs. C: P < 0.0001).
  
  
  CONCLUSIONS
  The use of b = 2000 s/mm(2) for DWI with 3-T MRI is diagnostically superior to that of b = 1000 s/mm(2) for prostate cancer detection.
authors.affiliation: Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Japan. yonu0121@yahoo.co.jp
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Ueno
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kitajima
authors.forename: Kazuro
authors.initials: K
authors.lastname: Sugimura
authors.forename: Fumi
authors.initials: F
authors.lastname: Kawakami
authors.forename: Hideaki
authors.initials: H
authors.lastname: Miyake
authors.forename: Makoto
authors.initials: M
authors.lastname: Obara
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
mesh_terms: D000368:Aged; D000465:Algorithms; D038524:Diffusion Magnetic Resonance Imaging; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000473:pathology*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
keywords: 3-T MRI; b = 2000 s/mm2; diffusion-weighted imaging (DWI); prostate cancer; ultra-high b-value