Angular Integration Autocorrelation Approach for Shear Wave Speed Estimation in the Framework of Reverberant Shear Wave Elastography

Reverberant Shear Wave Elastography (RSWE) is a novel imaging modality with promising outcomes across various clinical applications. The current estimation approach assumes a significantly isotropic distribution of the shear waves within the medium, which may not be achieved in all cases. Therefore, this study proposes the Angular Integration Autocorrelation (AIA) approach that calculates the angular average value around the 2D autocorrelation, producing a robust single 1D function of radial lag for efficient estimation of local wavenumber and SWS. The effectiveness of the AIA estimator for SWS estimation is first validated using a k-Wave simulation of a stiff branching tube in a uniform background. To further evaluate the effectiveness of the AIA estimator, ultrasound elastography experiments are conducted across a range of different excitation frequencies on a breast phantom with a lesion. The results demonstrate that compared with simple autocorrelation approaches, the AIA estimator improves both the accuracy of the estimated SWS and the signal-to-noise ratio (SNR) in estimating SWS.