title: MR spectroscopic imaging and diffusion-weighted imaging of prostate cancer with Gleason scores.
abstract: OBJECTIVE
  To investigate functional changes in prostate cancer patients with three pathologically proven different Gleason scores (GS) (3+3, 3+4, and 4+3) using magnetic resonance spectroscopic imaging (MRSI) and diffusion-weighted imaging (DWI).
  
  
  METHODS
  In this study MRSI and DWI data were acquired in 41 prostate cancer patients using a 1.5T MRI scanner with a body matrix combined with an endorectal coil. The metabolite ratios of (Cho+Cr)/Cit were calculated from the peak integrals of total choline (Cho), creatine (Cr), and citrate (Cit) in MRSI. Apparent diffusion coefficient (ADC) values were derived from DWI for three groups of Gleason scores. The sensitivity and specificity of MRSI and DWI in patients were calculated using receiver operating characteristic curve (ROC) analysis.
  
  
  RESULTS
  The mean and standard deviation of (Cho+Cr)/Cit ratios of GS 3+3, GS 3+4, and GS 4+3 were: 0.44 ± 0.02, 0.56 ± 0.06, and 0.88 ± 0.11, respectively. For the DWI, the mean and standard deviation of ADC values in GS 3+3, GS 3+4, and GS 4+3 were: 1.13 ± 0.11, 0.97 ± 0.10, and 0.83 ± 0.08 mm(2) /sec, respectively. Statistical significances were observed between the GS and metabolite ratio as well as ADC values and GS.
  
  
  CONCLUSIONS
  Combined MRSI and DWI helps identify the presence and the proportion of aggressive cancer (ie, Gleason grade 4) that might not be apparent on biopsy sampling. This information can guide subsequent rebiopsy management, especially for active surveillance programs.
authors.affiliation: Department of Radiological Sciences, David Geffen School of Medicine, University of California-Los Angeles, 10833 Le Conte Ave., Los Angeles, CA 90095-1721, USA.
authors.forename: Rajakumar
authors.initials: R
authors.lastname: Nagarajan
authors.forename: Daniel
authors.initials: D
authors.lastname: Margolis
authors.forename: Steven
authors.initials: S
authors.lastname: Raman
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Sarma
authors.forename: Ke
authors.initials: K
authors.lastname: Sheng
authors.forename: Christopher R
authors.initials: CR
authors.lastname: King
authors.forename: Gaurav
authors.initials: G
authors.lastname: Verma
authors.forename: James
authors.initials: J
authors.lastname: Sayre
authors.forename: Robert E
authors.initials: RE
authors.lastname: Reiter
authors.forename: M Albert
authors.initials: MA
authors.lastname: Thomas
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D006801:Humans; D008279:Magnetic Resonance Imaging; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D014408:Biomarkers, Tumor