title: Quantitative characterization of viscoelastic properties of human prostate correlated with histology.
abstract: Quantification of mechanical properties of human prostate tissue is important for developing sonoelastography for prostate cancer detection. In this study, we characterized the frequency-dependent complex Young's modulus of normal and cancerous prostate tissues in vitro by using stress relaxation testing and viscoelastic tissue modeling methods. After radical prostatectomy, small cylindrical tissue samples were acquired in the posterior region of each prostate. A total of 17 samples from eight human prostates were obtained and tested. Stress relaxation tests on prostate samples produced repeatable results that fit a viscoelastic Kelvin-Voigt fractional derivative (KVFD) model (r(2)>0.97). For normal (n = 8) and cancerous (n = 9) prostate samples, the average magnitudes of the complex Young's moduli (|E*|) were 15.9 +/- 5.9 kPa and 40.4 +/- 15.7 kPa at 150 Hz, respectively, giving an elastic contrast of 2.6:1. Nine two-sample t-tests indicated that there are significant differences between stiffness of normal and cancerous prostate tissues in the same gland (p < 0.01). This study contributes to the current limited knowledge on the viscoelastic properties of the human prostate, and the inherent elastic contrast produced by cancer.
authors.affiliation: Department of Biomedical Engineering, University of Rochester, Rochester, NY 14627, USA. mazhang@seas.rochester.edu
authors.forename: Man
authors.initials: M
authors.lastname: Zhang
authors.forename: Priya
authors.initials: P
authors.lastname: Nigwekar
authors.forename: Benjamin
authors.initials: B
authors.lastname: Castaneda
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hoyt
authors.forename: Jean V
authors.initials: JV
authors.lastname: Joseph
authors.forename: Anthony
authors.initials: A
authors.lastname: di Sant'Agnese
authors.forename: Edward M
authors.initials: EM
authors.lastname: Messing
authors.forename: John G
authors.initials: JG
authors.lastname: Strang
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Rubens
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Parker
mesh_terms: D000368:Aged; D004548:Elasticity; D054459:Elasticity Imaging Techniques; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011467:Prostate / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000502:physiology* / Q000503:physiopathology; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D013048:Specimen Handling / Q000379:methods; D013314:Stress, Mechanical; D014783:Viscosity