RESUMEN
The paper presents an application of the FSI technique to determine hemodynamics in the abdominal aorta (AA). To establish boundary conditions for the FSI study, MR anatomical data and 4D MRI velocity-mapping data (in three blood flow velocity directions and time) were collected to acquire realistic geometry of the AA and blood velocity. The mechanical parameters of the patient-specific aortic wall were applied in FSI simulations to describe wall mechanics and blood flow in the AA. Comparison of calculated and measured blood flow patterns and flow rate waveforms shows good agreement, which proves that wall pulsations should be incorporated into simulations that determine hemodynamics in the AA. The results of this work suggest that FSI analysis based on patient-specific data, such as the mechanical parameters of the aortic wall, real geometry of the aorta, and 4D flow information, might be used to predict the development of cardiovascular diseases.
Asunto(s)
Aorta Abdominal/anatomía & histología , Aorta Abdominal/fisiología , Velocidad del Flujo Sanguíneo/fisiología , Angiografía por Resonancia Magnética/métodos , Modelos Cardiovasculares , Presión Sanguínea/fisiología , Simulación por Computador , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Imagenología Tridimensional/métodos , Flujo Pulsátil/fisiología , Resistencia al Corte/fisiología , Estrés MecánicoRESUMEN
In this study, a fluid-structure interaction analysis based on the application of patient-specific mechanical parameters of the aneurismal walls was carried out to predict the rupture side during an abdominal aortic aneurysm (AAA). Realistic geometry of the aneurysm was reconstructed from CT data acquired from the patient, and patient-specific flow conditions were applied as boundary conditions. A newly developed non-invasive methodology for determining the mechanical parameters of the patient-specific aortic wall was employed to simulate realistic aortic wall behaviors. Analysis of the results included time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and von Mises stress (VMS). Results of the TAWSS, OSI, and VMS were compared to identify the most probable region of the AAA's rupture. High OSI, which identified the region of wall degradation, coincided with the location of maximum VMS, meaning that the anterior part of the aneurismal wall was a potential region of rupture.