title: A feasibility study of MR elastography in the diagnosis of prostate cancer at 3.0T.
abstract: BACKGROUND
  MR elastography is a new imaging tool capable of non-invasively assessing the viscoelastic properties of tissues. The clinical application of MR elastography in the diagnosis of prostate cancer remains to be elucidated.
  
  
  OBJECTIVE
  To investigate the feasibility of MR elastography in the diagnosis of prostate cancer at 3.0T, and to assess the elasticity and viscosity of prostate cancer and benign prostatic disease.
  
  
  METHODS
  Eight patients (63 ± 7.25 years old) with 12 foci of prostate cancer and 10 patients (59 ± 3.25 years old) with 14 foci of prostatitis in the peripheral zone were evaluated by MRE. Ten healthy volunteers (41 ± 4.32 years old) with 18 ROIs in the peripheral zone of the prostate were also assessed with MR elastography as a control group. The results were confirmed by histopathological findings. All examinations were performed on a 3.0T Philips Achieva scanner. MRE was implemented by transmitting low-frequency longitudinal mechanical waves of 100Hz into the prostate with a transducer placed above the pubic bones. The phase images were reconstructed to acquire viscoelastic mapping. T-test was used to compare the mean elasticity and viscosity of prostate cancer and prostatitis. A comparison of prostate cancer and healthy prostate tissue in elasticity was also evaluated. The correlation of elasticity and Gleason scores between prostate cancer and prostatitis were retrospectively analyzed with Pearson Correlation.
  
  
  RESULTS
  The mean elasticity and viscosity were significantly higher in the lesions with prostate cancer (6.55 ± 0.47 kPa, 6.56 ± 0.99 Pa.s, respectively) than in regions with prostatitis (1.99 ± 0.66 kPa, 2.13 ± 0.21 Pa.s). The difference between prostate cancer and prostatitis was statistically significant (t = 19.392, p < 0.01; t = 16.372, p < 0.01). The elasticity and viscosity of the healthy peripheral zone of prostate were 2.26 ± 0.45 kPa, 2.38 ± 0.54 Pa.s, respectively. There also was significant difference in elasticity between prostate cancer and normal peripheral zone (t = 25.136, p < 0.01). In addition, we observed a positive correlation between Gleason scores and elasticity of the prostate cancer (r = 0.913, P < 0.01) in this study.
  
  
  CONCLUSIONS
  MR elastography can be used to visualize the difference in stiffness between prostate cancer and benign prostatic disease. It is a new imaging method with potential in the diagnosis of prostate cancer.
authors.affiliation: Department of Radiology, Beijing Hospital, China.
authors.forename: Saying
authors.initials: S
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Chen
authors.forename: Wenchao
authors.initials: W
authors.lastname: Wang
authors.forename: Weifeng
authors.initials: W
authors.lastname: Zhao
authors.forename: Jianye
authors.initials: J
authors.lastname: Wang
authors.forename: Xuna
authors.initials: X
authors.lastname: Zhao
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhou
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D054459:Elasticity Imaging Techniques / Q000379:methods*; D005240:Feasibility Studies; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011471:Prostatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012189:Retrospective Studies