Bayesian shear wave speed estimation for in vivo 3D imaging of the prostate

Shear wave elasticity imaging (SWEI) has shown promise for visualizing structure and pathology within multiple organs; however, due to the assumptions of time of flight algorithms, artifacts caused by reflected waves at structural boundaries may be present in the images. The maximum a posteriori (MAP) estimator provides a framework for Bayesian estimation of the shear wave speed in order to reduce the artifacts and noise in SWEI images. Finite element method simulations and data acquired in a calibrated CIRS phantom show reductions in the bias and variance of the shear wave speed estimates compared to least squares linear regression. In vivo data are presented along with concurrently acquired acoustic radiation force impulse (ARFI) images demonstrating correlation between the elasticity imaging modalities.