CONSTRUCTION OF 3-D ARTERIAL VOLUME MESHES FROM MAGNETIC-RESONANCE ANGIOGRAPHY

Finite element methods are well-suited for solving problems in arteria l fluid dynamics, primarily due to their ability to handle flows in co mplex geometries. However, in order to use these computational methods to develop realistic models of pulsatile now in intracranial arteries and associated aneurysms, it is necessary to construct a 3-D mesh, or grid, that accurately duplicates the arterial geometry of interest. I n this paper, we present an efficient method to accurately develop rea listic 3-D computational meshes of human intracranial arteries and ane urysms from serial magnetic resonance angiography images. However, the se techniques may be applied to any other form of imaging data includi ng computed tomographic angiography. First, raw grayscale images are s egmented, converted to their binary form and arterial contours are ext racted at each image slice. Next, the arterial contours are stacked an d cubic splines are computed along the axial direction. This creates a n affect similar to smooth integration in the axial direction and prov ides a set of points that define the 3-D arterial surface geometry. Th en, surface patches are constructed and merged. A surface mesh is then computed with the ability to locally vary the mesh density as desired . Finally, nodal points on the surface mesh are used to compute the fi nite element volume mesh. The 3-D volume mesh accurately describes the arterial geometry and is used to develop patient-specific computation al fluid dynamic models of flow phenomena in intracranial arteries and aneurysms. These flow models are then suitable for investigating the hemodynamics of intracranial aneurysm formation and test the end-effec ts of various medical and surgical treatments.