Abstract
Tissue elasticity measurements by an ultrasonic wave are a promising technique for the qualitative diagnosis of tumors and liver diseases. The viscoelastic characteristics in soft tissue can be quantitatively evaluated by considering the frequency dependence of the velocity of the shear wave propagating in the tissue. To improve the reliability of the in vivo viscoelasticity measurement, we propose a novel elasticity imaging method using continuous vibration wave excitation, which was realized by developing a three dimensional ultrasonic (3D US) wave Doppler measurement system with multiple-frequency excitation. In vivo experiments on the brachial muscle were carried out in order to demonstrate the validity and effectiveness of the developed system. The experimental results show that this system can successfully measure the velocity of a shear wave propagating through a muscle layer. This system has the potential to obtain viscoelastic information from a target with high repeatability and reliability.