USE OF COMPUTATIONAL FLUID DYNAMICS FOR THE REPLICATION OF CLINICAL BLOOD FLOW AND PRESSURE MEASUREMENTS AND CHARACTERIZATION OF HEMODYNAMICS IN THE NORMAL ASCENDING AND THORACIC AORTA

摘要

Complications associated with abnormalities of the ascending and thoracic aorta are directly influenced by mechanical forces. To understand hemodynamic alterations associated with diseases in this region, however, we must first characterize related indices during normal conditions. Computational fluid dynamics (CFD) models of the ascending and thoracic aorta to date have only provided descriptions of the velocity field using idealized representations of the vasculature, a single patient data set, and outlet boundary conditions that do not replicate physiologic blood flow and pressure. Importantly, the complexity of aortic flow patterns, limited availability of methods for implementing appropriate boundary conditions, and ability to replicate vascular anatomy all contribute to the difficulty of the problem and, likely, the scarcity of more detailed studies. The objective of the current work was to investigate blood flow, pressure and distributions of wall shear stress (WSS) in a group of participants (n=5) with normal vascular anatomy by combining clinical imaging data with novel CFD techniques. Subject-specific CFD models were constructed from magnetic resonance imaging (MRI) data, and outlet boundary conditions that enable the replication of blood flow and pressure measurements were applied. Results were compared to clinical measurements and blood flow, pressure, and distributions of WSS were characterized to further elucidate normal values and behavior for this portion of the vasculature.