Measurement of skin elasticity using high frequency ultrasound elastography with intrinsic deformation induced by arterial pulsation

Mechanical property of the skin is one of the important factors for diagnosis of human skin diseases. In this paper, we proposed a novel method for estimation of shear wave velocity from deformation induced by an arterial pulsation. The induced deformation was measured by high frequency ultrasound. The elasticity of the in vivo human skin is evaluated based on the calculated parameters. P(VDF-TrFE) transducer with the central frequency of 100 MHz was used for imaging. The aperture diameter of the transducer was 2 mm, and the focal length was 4 mm. The repetition rate was 2,600 Hz. The sampling rate was 1 GS/s with 8 bit. The velocity induced by pulsation was measured by 1-D cross-correlation method at each depth. The shear wave velocity was estimated from the measured velocity. The shear wave velocity at the epidermis was 0.14 m/s, and the velocity at the dermis was 0.06 m/s. Because the stiffness of the skin was proportional to the shear wave velocity, the elasticity of the epidermis was higher than that of the dermis. These estimated elasticity well conformed to the histology of the skin and the past reports.