Multi-Plane Ultrafast Compound 3D Strain Imaging: Experimental Validation in a Carotid Bifurcation Phantom

Abstract

Featured Application: Noninvasive patient-friendly detection of vulnerable plaques in 3D segments of superficial arteries in cardiovascular risk populations.Abstract: Strain imaging of the carotid artery (CA) has demonstrated to be a technique capable of identifying plaque composition. This study assesses the performance of volumetric strain imaging derived from multi-plane acquisitions with a single transducer, with and without displacement compounding. These methods were compared to a reference method using two orthogonally placed transducers. A polyvinyl alcohol phantom was created resembling a stenotic CA bifurcation. A realistic pulsatile flow was imposed on the phantom, resulting in fluid pressures inducing 10% strains. Two orthogonally aligned linear array transducers were connected to two Verasonics systems and fixed in a translation stage. For 120 equally spaced elevational positions, ultrasound series were acquired for a complete cardiac cycle and synchronized using a trigger. Each series consisted of ultrafast plane-wave acquisitions at 3 alternating angles. Inter-frame displacements were estimated using a 3D cross-correlation-based tracking algorithm. Horizontal displacements were acquired using the single probe lateral displacement estimate, the single probe compounded by axial displacement estimates obtained at angles of 19.47 and −19.47 degrees, and the dual probe registered axial displacement estimate. After 3D tracking, least squares strain estimations were performed to compare compressive and tensile principal strains in 3D for all methods. The compounding technique clearly outperformed the zero-degree method for the complete cardiac cycle and resulted in more accurate 3D strain estimates.

In vivo carotid strain imaging using principal strains in longitudinal view

“…Myocardial elastography applications use principal strain to overcome the angle dependence of lateral and axial strain and centroid dependence of polar strains (Lee et al, 2008;Fung-Kee-Fung et al, 2005;Zervantonakis et al, 2007). Angle independent strains have also been reported for carotid strain imaging (Nayak et al, 2018;Mercure et al, 2014;Fekkes et al, 2018;Li et al, 2019;Porée et al, 2015). (Mercure et al, 2014) used a local angle compensation technique to account for heterogeneity in plaque and transducer angle dependence of axial strain.…”

Anti-aliasing method for ultrasonic 2D phase-sensitive motion estimator

“…Ultrasonography has been commonly used as a diagnostic tool for an early detection of a morphological change, and this imaging modality is suitable to be used for the screening examination. Also, quantitative evaluation methods such as the pulse wave imaging, 1,2) myocardial electromechanical wave imaging, 3,4) elastography, 5,6) and blood flow imaging have been investigated for an early detection of pathological change. Estimation accuracy of a motion estimator is critical for such in vivo applications.…”

Atherosclerotic carotid bifurcation phantoms with stenotic soft inclusions for ultrasound flow and vessel wall elastography imaging

“…Nowadays, new ultrasonic imaging modalities are developed for different applications. Non-invasive imaging methods such as vector flow mapping (Ekroll et al 2013, Pedersen et al 2014, Yiu et al 2014, pulse wave imaging (Shahmirzadi et al 2012), shear wave elastography (Couade et al 2010), natural pulsation elastography (Mercure et al 2014, Fekkes et al 2018, Nayak et al 2018, and vascular modulography (Porée et al 2017) have appeared in less than a decade for vascular applications or matured to get closer to clinical use (Nandlall andKonofagou 2016, Cloutier et al 2018). All these methods required phantom experiments as a first step validation.…”