Imaging of pulse wave propagation coupled with vector flow and wall shear stress mapping in atherosclerotic plaque phantoms and in vivo

Methods used in clinical practice to diagnose and monitor atherosclerosis present limitations. It has been reported that atherosclerosis alters the mechanical properties of the arterial wall, while the stiffness of a plaque can provide information on its risk for rupture and stroke occurrence. Pulse Wave Imaging (PWI) is a non-invasive, ultrasound-based technique, which provides information on arterial wall stiffness by imaging the pulse wave propagation along an arterial segment. Wall shear stress has also been considered as one of the key cardiovascular parameters associated with vascular wall degeneration and atherosclerosis initiation. The aim of the present study is to integrate PWI with Vector Doppler and Wall Shear stress in a single ultrasound imaging modality, enabling thus simultaneous and co-localized imaging of distension pulse wave propagation and hemodynamics. The performance of the proposed technique was evaluated in two phantoms with embedded plaques presenting 50% and 70% degree of stenosis, as well as through CFD simulations. Moreover, initial feasibility was demonstrated in an atherosclerotic human carotid artery in-vivo. Simultaneous compliance and flow measurements in the same artery could thus be obtained which can be used to both assess and monitor progression of vascular disease.