| Intimal thickening is a normal response to low wall shear stress. Such thickening is a reaction to certain predispositions and can eventually develop into atherosclerotic plaque. Insights to such progression in coronary arteries are at present very limited. The reason for this is that coronary vessels are relatively small and tortuous and furthermore, this tortuosity complicates the ability to localize plaque positions with respect to vessel curvature, cardiac motion and pressure and flow changes. However it can be hypothesized that the localized shear stress distribution in 3-Dimensional (3-D), time-dependent coronary lumen morphology is related to regional atherosclerotic plaque severity.; With this hypothesis, and the incorporation of accurate 3-Dimensional geometries of the coronary vessel morphology, the aim of this study was to develop a computational fluid dynamic (CFD) analysis to describe local flow dynamics in both 3-D spatial and 4-D spatial and temporal domains from reconstructions of intravascular ultrasound (IVUS) and bi-plane angiographic fusion images. The CFD model developed was validated with many known flow studies and found to be in very close agreement. Flow conditions considered both steady and unsteady simulations as well as the analysis of human coronary vessel segments that incorporated arterial motion. Arterial hemodynamics was related to the severity of atherosclerotic plaque and vessel morphology. The incorporation of arterial motion was found to impact the axial velocity contour and wall shear stress distributions and hence may provide more realistic predictions on the progression and locations of atherosclerotic plaque. |
