Model-based complex shear modulus reconstruction: A Bayesian approach

A narrow-band ultrasonic shear-wave imaging technique for estimating the complex shear modulus was applied to gelatin phantoms. This Bayesian approach incorporates the spatiotemporal geometry of shear waves radiating from a vibrating needle into a method for estimating modulus parameters. Compared to the phase gradient approach, this Bayesian method provides viscoelastic reconstructions for a single shear wave frequency. Estimates compare closely to results obtained using phase gradient method but with higher spectral resolution. We validated the assumption that the Kelvin-Voigt model, commonly applied in elasticity imaging situations, is representative of gelatin dispersion within the testing bandwidth between 50 and 450 Hz.