Enhanced Real-Time Ultrasound Elastography with Phase Gradient

Elastography is a well-practiced, non-invasive technique for imaging mechanical deformations to quantify the stiffness of tissues. The current methods of estimating shear wave velocity may often be troubled by issues of viscoelastic dispersion and computational complexity. A new algorithm is proposed in this paper, where a combination of the angular spectrum method and a local phase gradient estimator improves wavenumber determination in shear wave elastography. Testing on phantoms with homogeneous, rigid, and soft inclusions was performed by this algorithm. The average phase velocity obtained in the phase velocity map was 1.58 m/s with a standard deviation of 0.05 m/s for the homogeneous phantom. On the other hand, in heterogeneous phantoms, velocities ranged from 1 to 3 m/s. The method achieved an average reconstruction time of 0.253 s by averaging over nine frequency bands and two push locations. This algorithm achieves much-reduced computational complexity for high accuracy scanning; therefore, it offers a great improvement toward real-time elastography applications.