title: Computational hemodynamics of abdominal aortic aneurysms: Three-dimensional ultrasound versus computed tomography.
abstract: The current criterion for surgical intervention in abdominal aortic aneurysms, based upon a maximal aortic diameter, is considered conservative due to the high mortality rate in case of rupture. The research community is actively investigating the use of computational mechanics tools combined with patient-specific imaging to help identify more accurate criteria. Widespread uptake of a successful metric will however be limited by the need for computed tomography, which is at present the primary image extraction method on account of the location and complex shape of the aneurysms. The use of three-dimensional ultrasound as the scanning method is more attractive on account of increased availability, reduced cost and reduced risk to patients. The suitability of three-dimensional ultrasound is assessed for this purpose in the present work; computational fluid dynamics simulations were performed on geometries obtained from the same patient using both ultrasound and computed tomography. The influence of different smoothing algorithms is investigated in the geometry preparation stage and Taubin's low-pass filter was found to best preserve geometry features. Laminar, Newtonian, steady-state simulation analysis identified haemodynamic characteristics to be qualitatively similar in terms of wall shear stress, velocity and vorticity. The study demonstrates the potential for three-dimensional ultrasound to be integrated into a more accessible patient-specific modelling tool able to identify the need for surgical intervention of abdominal aortic aneurysms.
authors.affiliation: School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, UK benjamin.owen@manchester.ac.uk.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Owen
authors.affiliation: Institute of Cardiovascular Sciences, The University of Manchester, Manchester, UK.
authors.forename: Christopher
authors.initials: C
authors.lastname: Lowe
authors.affiliation: School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, UK Oxford e-Research Centre, University of Oxford, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Ashton
authors.affiliation: School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, UK.
authors.forename: Parthasarathi
authors.initials: P
authors.lastname: Mandal
authors.affiliation: Institute of Cardiovascular Sciences, The University of Manchester, Manchester, UK.
authors.forename: Steven
authors.initials: S
authors.lastname: Rogers
authors.affiliation: ImFusion GmbH, Munich, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Wein
authors.affiliation: Institute of Cardiovascular Sciences, The University of Manchester, Manchester, UK.
authors.forename: Charles
authors.initials: C
authors.lastname: McCollum
authors.affiliation: School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester, UK.
authors.forename: Alistair
authors.initials: A
authors.lastname: Revell
mesh_terms: D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging*; D006439:Hemodynamics; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D012039:Regional Blood Flow; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography
keywords: Abdominal aortic aneurysms; computational fluid dynamics; patient specific; three-dimensional ultrasound