Numerische Simulation pulsierender Strömungen in Blutgefäßen des Gehirns mit Aneurysmen mittels Lattice-Boltzmann-Verfahren

A major prerequisite for successful planning and control of the medical treatment of blood vessels with stenoses or aneurysms is the detailed knowledge of the individual situation in the damaged vessels. Modern tomography methods provide good spatial resolution, so that vessel walls as well as prostheses can be easily and rapidly identified. However, the mechanical loads of the walls remain largely unknown. In the past few years, tomography data have been used for spatial and temporal simulations of the blood flow in such vessels and to predict the mechanical loads of the vessel walls. The methodologies used so far, however, involve elaborate grid generation and simulation steps, most often relying on commercial software suited for engineering projects. These require specific knowledge and experience in mechanics and numerical simulation, and are therefore inappropriate for clinical applications. It is now shown, by example of an intracranial aneurysm, that employing a Lattice Boltzmann method for the flow simulation allows to avoid all mentioned drawbacks and to simulate blood flows in a fast and simple way that is also appropriate for clinical use. The practical relevance of such simulations will be enhanced by a better understanding of the correlations between pathology and specific mechanical loads. The paper discusses also some aspects of fluid mechanics that are relevant for the study of aneurysms.