title: Incremental value of high b value diffusion-weighted magnetic resonance imaging at 3-T for prediction of extracapsular extension in patients with prostate cancer: preliminary experience.
abstract: OBJECTIVE
  To investigate whether high b value diffusion-weighted imaging (DWI) contributes to the improvement of diagnostic ability of extracapsular extension (ECE) in prostate cancer (PC).
  
  
  METHODS
  Forty-three patients with PC underwent multiparametric MRI including DWI (b values: 0, 2000 s/mm2) at 3-T. Two radiologists assessed the presence of ECE and the diagnostic certainty degree using conventional diagnostic method by consensus. Tumor apparent diffusion coefficient (ADC, ×10-3mm2/s) was also measured. Independent predictors of ECE were identified among PSA, tumor ADC, Gleason score, and conventional MRI. ECE in patients with low diagnostic certainty by conventional MRI was further reevaluated using ADC cutoff value, and the results were combined with those of patients with high diagnostic certainty by conventional MRI (MRI + ADC method).
  
  
  RESULTS
  Tumor ADC was an independent predictor of ECE, and the ADC cutoff value was 0.72. The sensitivity, specificity, and accuracy of conventional MRI and MRI + ADC method in the diagnosis of ECE were 44, 92, and 72%, and 78, 96, and 88%, respectively. Among MRI findings leading to the judgement of low diagnostic certainty, broad tumor contact was most common (72% of the patients).
  
  
  CONCLUSIONS
  The addition of ADC obtained with high b value DWI at 3-T to conventional MRI improved the diagnostic ability of ECE.
authors.affiliation: Department of Radiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan. a-k.24@med.kawasaki-m.ac.jp.
authors.forename: Ayumu
authors.initials: A
authors.lastname: Kido
authors.affiliation: Department of Radiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tamada
authors.affiliation: Department of Radiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan.
authors.forename: Teruki
authors.initials: T
authors.lastname: Sone
authors.affiliation: Department of Pathology, Kawasaki Medical School, Kurashiki City, Okayama, 701-0192, Japan.
authors.forename: Naoki
authors.initials: N
authors.lastname: Kanomata
authors.affiliation: Department of Urology, Kawasaki Medical School, Kurashiki City, Okayama, 701-0192, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Miyaji
authors.affiliation: Department of Radiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: Department of Radiology, Kawasaki Medical School, 577 Matsushima, Kurashiki City, Okayama, 701-0192, Japan.
authors.forename: Katsuyoshi
authors.initials: K
authors.lastname: Ito
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D011467:Prostate / Q000000981:diagnostic imaging* / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000000981:diagnostic imaging* / Q000473:pathology*; D012044:Regression Analysis; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen
keywords: Apparent diffusion coefficient; Diffusion-weighted magnetic resonance imaging; Prediction; Prostatic neoplasm; Tumor staging