CPC A61B 8/0858 (2013.01) [A61B 8/463 (2013.01); A61B 8/485 (2013.01); A61B 8/5215 (2013.01); A61B 8/5269 (2013.01); A61B 8/543 (2013.01); G01S 7/52053 (2013.01); G01S 15/8915 (2013.01)] | 16 Claims |
1. An ultrasound imaging system for shear wave imaging comprising:
an ultrasound transducer configured to acquire echoes responsive to ultrasound pulses transmitted toward a bounded target tissue, wherein the bounded target tissue comprises tissue of finite size;
a beamformer configured to:
transmit, from the ultrasound transducer, tracking pulses in response to a push pulse, wherein the push pulse generates shear waves in the bounded target tissue and the tracking pulses are spatially planned to intersect the shear waves at one or more locales; and
receive, from the ultrasound transducer, echo signals where the tracking pulses intersected the shear waves; and
a processor in communication with the beamformer and configured to:
store tracking echo data generated from the received echo signals;
determine a thickness of the bounded target tissue and an angular orientation of the bounded target tissue relative to the ultrasound transducer and the push pulse;
apply a directional filter to the tracking echo data to generate directionally filtered shear wave data based on the thickness of the bounded target tissue and the angular orientation of the bounded target tissue relative to the ultrasound transducer and the push pulse;
estimate velocities of the shear waves at different shear wave frequencies based on the filtered shear wave data by fitting the filtered shear wave data to a Lamb wave model; and
determine a stiffness value of the bounded target tissue using the estimated velocities and the thickness of the bounded target tissue and the angular orientation of the bounded target tissue.
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