Phase aberration in ultrasound shear wave elastography - impacts on push and tracking

In ultrasound shear wave elastography (SWE), phase aberration can impact both push and tracking beams. From the literature, however, it is not clear whether performance loss in tissue stiffness reconstruction should be attributed more to push or tracking. To answer this question, we developed a research prototype based on a commercial ultrasound scanner EPIQ (Philips Healthcare, Andover, MA, USA) and a curvilinear array C5-1 (Philips Healthcare). Artificial delays were added into transmit and receive beamforming to introduce phase aberration. By switching on and off the phase screen independently in the push and tracking beams, we could create imaging conditions with no phase aberration, push-only aberration, tracking-only aberration, and aberration in both push and tracking. Our results based on 2 tissue-mimicking elastic phantoms, 3 probe-surface phase screens, and 2 center frequencies indicate that phase aberration alone deteriorates SWE reconstruction performance mainly through degrading tracking beams. To improve SWE in the presence of strong aberration, it is essential to restore tracking beam quality.