title: Turbulence intensity measurements using particle image velocimetry in diseased carotid artery models: effect of stenosis severity, plaque eccentricity, and ulceration.
abstract: Clinical decision-making for the treatment of patients with diseased carotid artery is mainly based on the severity of the stenosis. However, stenosis severity alone is not a sensitive indicator, and other local factors for the assessment of stroke risk are required. Flow disturbance is of particular interest due to its proven association with increased thromboembolic activities. The objective of this study was to investigate the level of turbulence intensity (TI) with regards to certain geometrical features of the plaque - namely stenosis severity, eccentricity, and ulceration. A family of eight carotid-artery bifurcation models was examined using particle image velocimetry. Results showed a marked difference in turbulence intensity among these models; increasing degree of stenosis severity resulted in increased turbulence intensity, going from 0.12 m/s for mild stenosis to 0.37 m/s for severe stenosis (with concentric geometry). Moreover, independent of stenosis severity, eccentricity led to further elevations in turbulence intensity, increasing TI by 0.05-0.10 m/s over the counterpart concentric plaque. The presence of ulceration (in a 50% eccentric plaque) produced a larger portion of moderate turbulence intensity (~0.10 m/s) compared to the non-ulcerated model, more proximal to the bifurcation apex in the post-stenotic recirculation zone. The effect of plaque eccentricity and ulceration in enhancing the downstream turbulence has potential clinical implications for a more sensitive assessment of stroke risk beyond stenosis severity alone.
authors.affiliation: Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7, Canada.
authors.forename: Sarah
authors.initials: S
authors.lastname: Kefayati
authors.affiliation: Department of Surgery, University of Western Ontario, London, ON, Canada; Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada.
authors.forename: David W
authors.initials: DW
authors.lastname: Holdsworth
authors.affiliation: Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, ON N6A 3K7, Canada; Imaging Research Laboratories, Robarts Research Institute, London, ON, Canada. Electronic address: poepping@uwo.ca.
authors.forename: Tamie L
authors.initials: TL
authors.lastname: Poepping
mesh_terms: D000465:Algorithms; D002339:Carotid Arteries / Q000503:physiopathology*; D016893:Carotid Stenosis / Q000503:physiopathology*; D003251:Constriction, Pathologic / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008953:Models, Anatomic; D008962:Models, Theoretical; D058226:Plaque, Atherosclerotic; D012212:Rheology
keywords: Atherosclerosis; Plaque eccentricity; Stenosis severity; Stereoscopic PIV; Stroke; Thrombosis; Turbulence intensity; Ulceration