Investigating the Degree of Shear Wave Speed Anisotropy as a Function of Studied Ventricular Zone

In order for shear wave elastography (SWE)to be a quantitative imaging tool for myocardial stiffness, it is important to eliminate or reduce the non-disease related factors that affect myocardial stiffness estimation. It is known for shear wave speed ─ representative of myocardial stiffness in cardiac SWE ─ to be dependent on multiple factors such as fiber orientation and loading state. In this study, we have demonstrated the degree of shear wave speed anisotropy as a function of the analyzed left ventricular (LV)region and axial depth and have found the traditional long axis view in transthoracic SWE to give more consistent results across LV zone and depth compared to the short axis view. In addition, the shear wave speed anisotropy, recently proposed as an extra diagnostic marker, is shown to be dependent on the selected axial depth and LV region.