A novel approach to assessing changes in prostate stiffness with age using virtual touch tissue quantification.

ABSTRACT

OBJECTIVES: Virtual touch tissue quantification is a promising new implementation of the acoustic radiation force impulse ultrasound technique. The purposes of this study were to describe the normal shear wave velocity values of the prostate by virtual touch tissue quantification and to examine the clinical usefulness of this procedure in evaluation of age-related shear wave velocity changes in the prostate. METHODS: One hundred twenty healthy volunteers were involved in this study. They were divided into 3 groups (40 participants per group) young (<30 years), middle aged (30-60 years), and old (>60 years). The shear wave velocity was measured at the inner and outer glands of the prostate at the maximum depth (~5.5 cm) in each participant. RESULTS: The mean shear wave velocities ± SD at the inner gland of the prostate in the young, middle-aged, and old groups were 0.86 ± 0.21, 1.17 ± 0.42, and 1.82 ± 0.61 m/s, respectively, whereas the velocities at the outer gland in the respective groups were 0.85 ± 0.32, 1.15 ± 0.49, and 1.87 ± 0.75 m/s. The shear wave velocities did not differ between the inner and outer glands in any age group. They were all significantly greater in the old group than in the young and middle-aged groups (P < .05). Moreover, the shear wave velocities at the inner and outer glands all correlated significantly with age. CONCLUSIONS: Virtual touch tissue quantification can provide numerical measurements of prostate stiffness and can effectively and objectively indicate age-related changes in prostate stiffness by measuring shear wave velocity values.