Cerebrovascular disease is the second leading cause of death worldwide and determining plaque vulnerability is critical to early intervention, selecting appropriate treatment, and reducing mortality rates. Shear wave elastography (SWE) is an ultrasound-based technique to characterize the mechanical properties of tissue and pulse wave imaging (PWI) is most commonly used to measure arterial stiffness by estimating the propagation speed of the pulse wave generated from left ventricular ejection. In this study, SWE and PWI were used to characterize three homogeneous plaque mimicking inclusions in three common carotid artery phantoms by using phase velocity (PV) and group velocity (GV) analysis as well as estimating the pulse wave velocity (PWV) using PWI. Thereafter, the estimated Young’s modulus values were compared in the phantom walls. The mean wave velocities in the plaques were 1.7 ± 0.2 m/s, 1.6 ± 0.1 m/s, and 2.5 ± 0.5 m/s calculated by PV, GV, and PWI, respectively. This was lower than the mean wave speeds measured in the vessel wall (3.8 ± 0.2 m/s, 3.5 ± 0.2 m/s, and 3.3 ± 0.1 m/s by PV, GV, and PWI, respectively) showing that both techniques can detect soft vulnerable plaques. The PWV estimate was more sensitive to plaque thickness compared to the SWE GV estimate. The results indicate the ability of SWE and PWI to characterize homogeneous plaques from the arterial wall.
Carotid Artery Phantom; Group Velocity; Shear Wave Elastography; Phase Velocity; Plaque Characterization; Pulse Wave Imaging; Pulse Wave Velocity; Stroke; Ultrasound