Robust shear wave speed measurement using comb-push Ultrasound Radiation Force

Measurement of shear wave propagation speed in tissues has clinical significance of indicating tissue stiffness and health state. Spatially Modulated Ultrasound Radiation Force (SMURF) imaging generates a shear wave of known wavelength in the tested material and measures the temporal frequency of the shear wave to determine shear wave propagation speed. Detection in SMURF is relatively simple, but the push beamforming is rather complicated. In this study we propose a new approach for push beamforming for SMURF. The ultrasound transducer elements are divided into several groups with inactive groups interleaving active ones that transmit unfocused push beams simultaneously to form comb-shaped radiation force field. We named such technique as “comb-push”. Both phantom and in vivo muscle results show consistent shear wave propagation speed measurement can be achieved using comb-push. Such a method potentially can be implemented in current commercially available ultrasound imaging systems.