Effect of Ultrafast Imaging on Shear Wave Visualization and Characterization: An Experimental and Computational Study in a Pediatric Ventricular Model

Abstract

Plane wave imaging in Shear Wave Elastography (SWE) captures shear wave propagation in real-time at ultrafast frame rates. To assess the capability of this technique in accurately visualizing the underlying shear wave mechanics, this work presents a multiphysics modeling approach providing access to the true biomechanical wave propagation behind the virtual image. This methodology was applied to a pediatric ventricular model, a setting shown to induce complex shear wave propagation due to geometry. Phantom experiments are conducted in support of the simulations. The model revealed that plane wave imaging altered the visualization of the shear wave pattern in the time (broadened front and negatively biased velocity estimates) and frequency domain (shifted and/or decreased signal frequency content). Furthermore, coherent plane wave compounding (effective frame rate of 2.3 kHz) altered the visual appearance of shear wave dispersion in both the experiment and model. This mainly affected stiffness characterization based on group speed, whereas phase velocity analysis provided a more accurate and robust stiffness estimate independent of the use of the compounding technique. This paper thus presents a versatile and flexible simulation environment to identify potential pitfalls in accurately capturing shear wave propagation in dispersive settings.

Period of Arrhythmia Anchored around an Infarction Scar in an Anatomical Model of the Human Ventricles

“…Note that mathematical methods are widely used in various applications in cardiology, such as in the basic study of arrhythmia sources [29], correlation of cardiovascular risk markers [30], to support and optimize the relevant choices in cardiac surgery via building us mathematical models [31], and to develop novel ways of assessment of properties of the heart via ultrafast shear wave imaging based on multiphysics platform which includes modeling parts [32].…”

Concepts and applications of ultrafast cardiac ultrasound imaging

“…This, however, comes at the cost of spatial resolution and a low signal‐to‐noise ratio, that is lower quality of the images, as the transmitted sound energy per scan line is much lower. In order to raise image quality again, coherent compounding of several successive diverging waves is used 10–12 …”

“…In order to raise image quality again, coherent compounding of several successive diverging waves is used. [10][11][12] While many aspects of myocardial mechanics can be analyzed with conventional echocardiographic imaging, higher temporal resolution offers additional information. We will show in the following how increasing the frame rate paves the way to fascinating new applications of echocardiography such as myocardial stiffness measurements, imaging of coronary flow, or visualizing intracavitary blood flow.…”

Parasternal Versus Apical View in Cardiac Natural Mechanical Wave Speed Measurements

“…However, Vos et al [21] only measured mild dispersion for SWs after AVC and MVC in pigs and, therefore, found a poor match with A 0 -Lamb wave modes. This same model was used in studies using external sources like an external shaker [10], [11], [34], [35], and ARF [33], [37]. However, it should be noted that when using an ARF source in a parasternal long-axis view, the load is directed perpendicular to the myocardium, inducing, therefore, mainly the transversal particle motion (and thus the A 0 -mode).…”