Speckle bias as a 3-D offset for the tracking location of shear wave imaging

In conventional, multiple track location shear wave elasticity imaging (MTL-SWEI), shear wave speeds are estimated by imaging wave propagation at multiple positions in the tissue with high speed ultrasound and comparing the motion measured at each location. The positions of the tracking beams are determined by transmit-receive beamforming. Because of stationary speckle noise, the precise position of each track beam varies from its prescribed location. This spatial speckle bias creates stationary offsets in the temporal characteristics of imaged waves and errors in velocity estimates. This work examines the speckle bias through simulations and experiments, and demonstrates methods for compensation.