On the use of local speckle field as a correction factor for shear modulus estimates based on multiple-track-locations methods

Acoustic-radiation-force impulse (ARFI) imaging for characterization of shear modulus of biological tissues employs either multiple-track-locations (MTL) methods or single-track-location (STL) methods. MTL estimates of shear modulus at different depths suffer from more variability compared to those of STL estimates. Our studies have shown a significant correlation between bias in shear-wave arrival time estimates and local speckle field lateral statistics. We propose using the local speckle field as a surrogate for the unknown bias apparent in MTL shear-wave speed estimates. This local speckle field is determined using a “swept-receive acquisition” that is produced by holding the transmit beam fixed while laterally translating the receive aperture. Application of various lateral weighting functions to the swept-receive image results in an approximate compensation to the tracking bias. In this study, we implement our technique on simulation and experimental data from gelatin phantoms. Additionally, the effect of varying transmit-receive aperture f/# on the accuracy of our compensation method is investigated in simulation. Finally, the quality of compensated MTL shear modulus images are quantified and compared to those of the uncompensated MTL and of STL methods in matched tissue mimicking phantom experiments.