A model-free approach to probe motion artifacts suppression for in vivo imaging with probe oscillation shear wave elastography (PROSE)

Shear wave elastography methods are able to accurately measure tissue stiffness, allowing these techniques to monitor the progression of hepatic fibrosis. While many methods rely on acoustic radiation force (ARF) to generate shear waves for two-dimensional (2D) imaging, probe oscillation shear wave elastography (PROSE) provides an alternative approach by generating shear waves through continuous vibration of the ultrasound probe while simultaneously detecting the resulting motion. The generated shear wave field in in vivo liver is complicated, and the amplitude and quality of these shear waves can be influenced by the placement of the vibrating probe. It was not possible to fully suppress residual motion artifacts with established filtering methods. Instead, the shear wave signal was decoupled from motion from other sources with empirical mode decomposition (EMD). This method was evaluated in a phantom as well as in in vivo livers from five volunteers. PROSE results were well correlated well with independent measurements using the commercial General Electric Logiq E9 scanner.