Precise Observation, Separation and Synthesis of Shear Waves Using Ultrasonic Vectoral Doppler Measurement and Spatio-Temporal Multidimensional Spectral Processing

Previously we performed high accuracy ultrasonic displacement vector measurements for a laterally compressed human soft tissue phantom with the 2D autocorrelation method (AM), and the lateral modulation or spectral filtering/division method, etc. Recently, a shear wave generated with a controlled propagation direction by push beams is observed for soft materials using a conventional 1D Doppler method. In this report, the vectoral Doppler measurement is applied to dynamically vibrated soft tissue phantoms in order to observe, more in detail or in a high precision, shear waves generated not under the control. Using our previously developed spatio-temporal multidimensional spectral processing methods such as filtering/division method, interference waves were separated, and new shear waves were also generated. The approach was also compared with our previously developed inverse approach. The 2 approaches were also applied to a human in vivo wrist tissue.