Sonoelastographic Shear Velocity Imaging: Experiments on Tissue Phantom and Prostate

In this paper, we introduce and evaluate a novel sonoelastographic technique for imaging shear velocity distributions from propagating shear wave interference patterns (termed crawling waves). A mathematical relationship between local crawling wave spatial phase derivates and shear velocity is presented with phase derivatives estimated using an autocorrelation-based technique. Results from homogeneous phantoms illustrate the ability of sonoelastographic shear velocity imaging to accurately quantify the true shear velocity distribution as verified using time-of-flight measurements. Results from a heterogeneous phantom reveal the ability of sonoelastographic shear velocity imaging to distinguish a stiff circular inclusion with shear velocity contrast comparable to that measured using mechanical testing techniques. High contrast visualization of focal carcinomas in an in-vitro prostrate specimen demonstrates the feasibility of this novel sonoelastographic imaging technique in tissue. Keywords-crawling waves; elasticity imaging; shear velocity estimation; sonoelastography.