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

Annette Caenen (1) , Mathieu Pernot (2, 3) , Ingvild Kinn Ekroll (4) , Darya Shcherbakova (1) , Luc Mertens (5) , Abigail Swillens (1) , Patrick Segers (1)

1 IBiTech-bioMMeda
2 Physique des ondes pour la médecine
3 IL - Institut Langevin - Ondes et Images (UMR7587)
4 NTNU - Norwegian University of Science and Technology [Trondheim]
5 University of Toronto

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.

Mots clés: ultrafast imaging; shear wave elastography; multiphysics modeling

Domaines: Imagerie; Biomécanique [physics.med-ph]

Annette Caenen, Mathieu Pernot, Ingvild Kinn Ekroll, Darya Shcherbakova, Luc Mertens, et al.. Effect of Ultrafast Imaging on Shear Wave Visualization and Characterization: An Experimental and Computational Study in a Pediatric Ventricular Model. Applied Sciences, 2017, 7 (8), pp.840. ⟨10.3390/app7080840⟩. ⟨hal-02481927⟩