title: Comparison of MRS and DWI in the diagnosis of prostate cancer based on sextant analysis.
abstract: OBJECTIVE
  To evaluate apparent diffusion coefficient (ADC) value, metabolic ratio ((Cho + Cr)/Cit) and the combination of the two in identifying prostate malignant regions.
  
  
  METHODS
  Fifty-six consecutive patients with prostate biopsy results were retrospectively recruited in this study. Transrectal ultrasound-guided (TRUS) systemic prostate biopsies were used as a standard of reference. Mean ADC value and mean metabolic ratio (MMR) were calculated within each benign sextant region or malignant region. The efficiency of these two indices in prostate cancer (PCa) diagnosis is estimated in Fisher linear discriminant analysis (FLDA). The area under the receiver operating characteristic (ROC) curve was used to evaluate the distinguishing capacity of mean ADC, MMR, and the combination of the two in differentiating between noncancerous and cancerous cases.
  
  
  RESULTS
  There were significant differences for mean ADC value and MMR between malignant and benign regions. Weights of mean ADC value obtained by FLDA were much higher than those of MMR. In differentiating malignant regions, both ADC alone and combined ADC and metabolic ratio performed significantly better than MMR alone. However, accuracy improvements were not significant by using combined ADC and MMR than ADC alone.
  
  
  CONCLUSIONS
  DWI is more efficient than MR spectroscopic (MRS) in the detection of PCa in this study. Combined ADC and MMR performed significantly better than MMR alone in distinguishing malignant from benign region in prostate peripheral zone.
authors.affiliation: College of Engineering, Peking University, Beijing, China, People's Republic of China.
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Wenchao
authors.initials: W
authors.lastname: Cai
authors.forename: Dongjiao
authors.initials: D
authors.lastname: Lv
authors.forename: Xuemei
authors.initials: X
authors.lastname: Guo
authors.forename: Jue
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wang
authors.forename: Jing
authors.initials: J
authors.lastname: Fang
mesh_terms: D000368:Aged; D001706:Biopsy; D003937:Diagnosis, Differential; D004058:Diffusion; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D017430:Prostate-Specific Antigen / Q000096:biosynthesis; D011471:Prostatic Neoplasms / Q000628:therapy*; D012372:ROC Curve; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
chemical_list: D017430:Prostate-Specific Antigen