Adaptive Wall Shear Stress Imaging in Phantoms, Simulations and In Vivo

• Published in: IEEE transactions on biomedical engineering Vol. 70; no. 1; pp. 154 - 165
• Main Authors: Karageorgos, Grigorios M., Kemper, Paul, Lee, Changhee, Weber, Rachel, Kwon, Nancy, Meshram, Nirvedh, Mobadersany, Nima, Grondin, Julien, Marshall, Randolph S., Miller, Eliza C., Konofagou, Elisa E.
• Format: Journal Article
• Language: English
• Published: United States IEEE 01.01.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Animals; Arteries; Arteriosclerosis; Atherogenic diet; Atherosclerosis; Atherosclerosis - diagnostic imaging; blood flow dynamics; Carotid arteries; Carotid Arteries - diagnostic imaging; Carotid artery; Clustering; Constriction, Pathologic; Correlation coefficient; Correlation coefficients; Estimation; Feasibility; Flow distribution; Flow profiles; Fluid-structure interaction; Humans; Imaging; Imaging techniques; Oscillations; Phantoms; plaque; Plaque, Atherosclerotic - diagnostic imaging; Plaques; pulse wave imaging; Radio frequency; Segments; Shear stress; Simulation; Stenosis; Stress, Mechanical; Swine; Ultrasonic imaging; Ultrasonic testing; vector flow imaging; Wall shear stress; Wall shear stresses
• ISSN: 0018-9294; 1558-2531; 1558-2531
• DOI: 10.1109/TBME.2022.3186854

WSS measurement is challenging since it requires sensitive flow measurements at a distance close to the wall. The aim of this study is to develop an ultrasound imaging technique which combines vector flow imaging with an unsupervised data clustering approach that automatically detects the region close to the wall with optimally linear flow profile, to provide direct and robust WSS estimation. The proposed technique was evaluated in phantoms, mimicking normal and atherosclerotic vessels, and spatially registered Fluid Structure Interaction (FSI) simulations. A relative error of 6.7% and 19.8% was obtained for peak systolic (WSS PS ) and end diastolic (WSS ED ) WSS in the straight phantom, while in the stenotic phantom, a good similarity was found between measured and simulated WSS distribution, with a correlation coefficient, R, of 0.89 and 0.85 for WSS PS and WSS ED , respectively. Moreover, the feasibility of the technique to detect pre-clinical atherosclerosis was tested in an atherosclerotic swine model. Six swines were fed atherogenic diet, while their left carotid artery was ligated in order to disturb flow patterns. Ligated arterial segments that were exposed to low WSS PS and WSS characterized by high frequency oscillations at baseline, developed either moderately or highly stenotic plaques (p < 0.05). Finally, feasibility of the technique was demonstrated in normal and atherosclerotic human subjects. Atherosclerotic carotid arteries with low stenosis had lower WSS PS as compared to control subjects (p < 0.01), while in one subject with high stenosis, elevated WSS was found on an arterial segment, which coincided with plaque rupture site, as determined through histological examination.