Diffuse shear wave elastography in a thin plate phantom

Abstract

The diastolic functioning of the left ventricle is correlated to the stiffness of the myocardium. Shear wave (SW) elastography can be used for non-invasive stiffness measurements. These waves can have external sources such as an acoustic push, natural sources such as valve closure, or diffuse sources like breathing and flow noise. SW propagation velocities in diffuse wave fields can be analyzed after a spatio-temporal correlation technique. This technique has been applied to bulk SW [Brum et al, IEEE UFFC 2015; Parker et al, Phys Med Biol 2017] and surface waves [Sabra et al, Am Inst Phys 2007; Brum et al, JASA 2008]. However, since the myocardium is relatively thin, Lamb wave phenomena including dispersion could be expected. In this study we tested the applicability of the diffuse wave technique in a PVA thin plate phantom, and compared it to direct SW measurements and a mechanically measured shear modulus.