title: Acquisition of 3-D arterial geometries and integration with computational fluid dynamics.
abstract: A system for acquisition of 3-D arterial ultrasound geometries and integration with computational fluid dynamics (CFD) is described. The 3-D ultrasound is based on freehand B-mode imaging with positional information obtained using an optical tracking system. A processing chain was established, allowing acquisition of cardiac-gated 3-D data and segmentation of arterial geometries using a manual method and a semi-automated method, 3D meshing and CFD. The use of CFD allowed visualization of flow streamlines, 2-D velocity contours and 3-D wall shear stress. Three-dimensional positional accuracy was 0.17-1.8mm, precision was 0.06-0.47mm and volume accuracy was 4.4-15%. Patients with disease and volunteers were scanned, with data collection from one or more of the carotid bifurcation, femoral bifurcation and abdominal aorta. An initial comparison between a manual segmentation method and a semi-automated method suggested some advantages to the semi-automated method, including reduced operator time and the production of smooth surfaces suitable for CFD, but at the expense of over-smoothing in the diseased region. There were considerable difficulties with artefacts and poor image quality, resulting in 3-D geometry data that was unsuitable for CFD. These artefacts were exacerbated in disease, which may mean that future effort, in the integration of 3-D arterial geometry and CFD for clinical use, may best be served using alternative 3-D imaging modalities such as magnetic resonance imaging and computed tomography.
authors.affiliation: Medical Physics, Sheffield University, Sheffield, UK.
authors.forename: Steven
authors.initials: S
authors.lastname: Hammer
authors.forename: Adam
authors.initials: A
authors.lastname: Jeays
authors.forename: Paul L
authors.initials: PL
authors.lastname: Allan
authors.forename: Rod
authors.initials: R
authors.lastname: Hose
authors.forename: David
authors.initials: D
authors.lastname: Barber
authors.forename: William J
authors.initials: WJ
authors.lastname: Easson
authors.forename: Peter R
authors.initials: PR
authors.lastname: Hoskins
mesh_terms: D000465:Algorithms; D001158:Arteries / Q000502:physiology*; D001783:Blood Flow Velocity / Q000502:physiology*; D003198:Computer Simulation; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008955:Models, Cardiovascular; D012212:Rheology / Q000379:methods*; D018511:Systems Integration; D014463:Ultrasonography / Q000379:methods*