Investigation of the effect of geometrical features of carotid artery plaque on turbulence intensity using Doppler ultrasound and particle image velocimetry

Stenosis severity alone is not a sensitive indicator of ischemic stroke risk; however, it remains the primary indicator for clinical decision-making. Carotid endarterectomy is strongly recommended for patients with severe stenosis, while treatment for lesser stenosis severity remains disputed. Thromboembolism is one of the major causes of ischemic stroke and has shown high correlation with hemodynamic factors, such as turbulence. Geometrical factors - such as the degree of stenosis severity, plaque eccentricity, and ulceration - can alter the local hemodynamics of the carotid artery, such as by inducing flow disturbances. The objective of this work was to investigate the impact of these geometrical features on the level of turbulence intensity using DUS and PIV. A family of carotid artery models was examined with geometries ranging from disease-free to severe stenosis, in both eccentric and concentric forms of plaque symmetry, and in the case of moderate stenosis (50%) with and without ulceration. Plaque eccentricity and ulceration were found to enhance the flow disturbances downstream of a stenosis, suggesting that clinical diagnosis should consider plaque shape and roughness in addition to stenosis severity.