Abstract 4216: Non-invasive Prediction of Localization and Progression of Coronary Disease in Man Using Shear Stress Profiles Derived from 320-Row Detector Computed Tomography: Implications for Widespread Screening
Introduction: Low endothelial shear stress (ESS) is the local stimulus for the development and progression of atherosclerosis. In-vivo identification of areas of low ESS using coronary angiography and IVUS identifies areas where high-risk plaques will form. Using 320-slice CT (16 cm coverage) it is now possible to obtain a still image of the coronary arteries without stair-step artifact. By combining a 320 -slice 3D image with established techniques for intracoronary flow mapping, we have non-invasively determined ESS for an entire coronary system to predict which regions might be at risk for the development of unstable plaques.
Methods: A standard workstation (Vitrea 4.0, Vital Images, Minnetonka, MN) was used to automatically segment the lumen of the coronary arteries after axial 320 × 0.5 mm CT (Toshiba, AquilonOne, Tochigi-ken, Japan). acquisition. Smoothing of the wall surface and calculations of local velocities and ESS were performed in 3-D by the Lattice-Boltzmann method using standard Muphy Code. Resolution was 0.1 mm. Blood viscosity was estimated from hematocrit.
Results: ESS for the left coronary artery system is shown below where low ESS is represented by dark shading and high ESS by light shading. Regions of low ESS occur as expected at bifurcations, at the inner wall of bends and in regions of larger arterial diameter.
Conclusions: Utilizing 320-slice CTA and new CFD methods it is now possible to create highly detailed maps of ESS non-invasively throughout the coronary artery tree. These proof-of-concept results suggest the potential for widespread, non-invasive identification of patients with coronary artery disease who are at risk for acute coronary events.