Shear Wave Imaging Framework for Quantification of Myocardial Tissue Properties

Background: Analyze of myocardial and arterial wall tissue properties can potentially be used to diagnose cardiovascular pathophysiology. Many cardiovascular diseases, such as Left Bundle Branch Block, Myocardial Infarcts and arteriosclerosis alters tissue elasticity. A known analogue to tissue elasticity is the velocity of the propagating shear waves through tissue, which can be quantified non-invasively as shear wave velocity, derived from ultrasound Shear-Wave Imaging (SWI). The use of SWI techniques requires custom programming and a deep knowledge of research-based ultrasound systems. The aim of the current work is to develop an open-source software toolbox for acquisition of SWI imaging.

Methods and results: A SWI framework were developed using one of the most widely used research-based ultrasound systems from Verasonics. The framework is capable of not only identifying natural shear waves in 800ms windows, but also generating an acoustic radiation force pulse for generating artificial shear waves in tissue, for use in linear and phased array setups. The MATLAB code and setup framework are provided as an open-source package is made available for use on GitHub. ARFI measurements in a tissue mimicking ultrasound phantom showed consistent shear wave velocities of 2.61±0.1 m/s, which did not vary significantly with respect to scan depth (P=0.67).

Conclusion: This framework is envisioned to be useful for aspiring researchers starting their work in SWI imaging using the Verasonics Vantage System.