Hemodynamic Simulations to Identify Irregularities in Coronary Artery Models

Abstract

Objectives: Nowadays invasive coronary angiogram is a gold standard clinical application to determine fractional flow reserve (FFR) over the world. The engineering tools computational fluid dynamics (CFD) enabled the simulation of coronary blood flow conditions in the idealized and patient-based coronary models. The CTA-based CFD simulation allowed us to produce a noninvasive assessment of the hemodynamic parameters, such as blood velocity magnitude, relative pressure difference and virtual fractional flow reserve (vFFR). These hemodynamic mechanisms provide the information on coronary stenosis conditions and predict the severity of coronary arterial lumen area which is responsible for the heart attack of the human patients. Methodology: In the current study investigates the hemodynamic parameters by using idealized coronary artery prototypical model and patient-specific real coronary artery models. The patient-specific model reconstructed by following steps: CTA image acquisition, image segmentation, 3D reconstruction, smooth surface and computational mesh generation. The hemodynamics simulation derived by solving the Navier-Stokes equations for steady and pulsatile flow motions. Results: The results reflect expected outcomes in both cases, for instance, a higher blood velocity in the coronary vessels tends to stretch the contrast agent gradient and a lower blood velocity magnitude tends to steepen the contrast agent gradient. The pressure difference and vFFR results allow to distinguish the unstenosed and stenosis arterial models. Conclusion: The aim of the work was to set up a framework for an idealized and a patientspecific models reconstruction, geometric analysis and describing hemodynamic parameters. The parameters allowed to describe the intrinsic blood flow in a non-invasive procedure. The simulation results are feasible for clinical applications but there are some limitations in the approaches which need more studies to overcome them.