title: From medical images to flow computations without user-generated meshes.
abstract: Biomedical flow computations in patient-specific geometries require integrating image acquisition and processing with fluid flow solvers. Typically, image-based modeling processes involve several steps, such as image segmentation, surface mesh generation, volumetric flow mesh generation, and finally, computational simulation. These steps are performed separately, often using separate pieces of software, and each step requires considerable expertise and investment of time on the part of the user. In this paper, an alternative framework is presented in which the entire image-based modeling process is performed on a Cartesian domain where the image is embedded within the domain as an implicit surface. Thus, the framework circumvents the need for generating surface meshes to fit complex geometries and subsequent creation of body-fitted flow meshes. Cartesian mesh pruning, local mesh refinement, and massive parallelization provide computational efficiency; the image-to-computation techniques adopted are chosen to be suitable for distributed memory architectures. The complete framework is demonstrated with flow calculations computed in two 3D image reconstructions of geometrically dissimilar intracranial aneurysms. The flow calculations are performed on multiprocessor computer architectures and are compared against calculations performed with a standard multistep route.
authors.affiliation: Department of Mechanical and Industrial Engineering, Seamans Center for the Engineering Arts and Sciences, The University of Iowa, Iowa City, IA, 52242-1527, USA; IIHR - Hydroscience and Engineering, C. Maxwell Stanley Hydraulics Laboratory, The University of Iowa, Iowa City, IA, 52242-1585, USA.
authors.forename: Seth I
authors.initials: SI
authors.lastname: Dillard
authors.forename: John A
authors.initials: JA
authors.lastname: Mousel
authors.forename: Liza
authors.initials: L
authors.lastname: Shrestha
authors.forename: Madhavan L
authors.initials: ML
authors.lastname: Raghavan
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Vigmostad
mesh_terms: D002533:Cerebral Angiography / Q000379:methods; D002560:Cerebrovascular Circulation; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D002532:Intracranial Aneurysm / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography / Q000379:methods; D015203:Reproducibility of Results; D012984:Software
keywords: cartesian grid methods; computational fluid dynamics; image-based modeling; level set method
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