title: Haemodynamics in the mouse aortic arch computed from MRI-derived velocities at the aortic root.
abstract: Mice are widely used to investigate atherogenesis, which is known to be influenced by stresses related to blood flow. However, numerical characterization of the haemodynamic environment in the commonly studied aortic arch has hitherto been based on idealizations of inflow into the aorta. Our purpose in this work was to numerically characterize the haemodynamic environment in the mouse aortic arch using measured inflow velocities, and to relate the resulting shear stress patterns to known locations of high- and low-lesion prevalence. Blood flow velocities were measured in the aortic root of C57/BL6 mice using phase-contrast MRI. Arterial geometries were obtained by micro-CT of corrosion casts. These data were used to compute blood flow and wall shear stress (WSS) patterns in the arch. WSS profiles computed using realistic and idealized aortic root velocities differed significantly. An unexpected finding was that average WSS in the high-lesion-probability region on the inner wall was actually higher than the WSS in the low-probability region on the outer wall. Future studies of mouse aortic arch haemodynamics should avoid the use of idealized inflow velocity profiles. Lesion formation does not seem to uniquely associate with low or oscillating WSS in this segment, suggesting that other factors may also play a role in lesion localization.
authors: Department of Bioengineering, MRC Clinical Sciences Centre, Imperial College London, UK.
authors: Mark A
authors: MA
authors: Van Doormaal
authors: Asimina
authors: A
authors: Kazakidi
authors: Marzena
authors: M
authors: Wylezinska
authors: Anthony
authors: A
authors: Hunt
authors: Jordi L
authors: JL
authors: Tremoleda
authors: Andrea
authors: A
authors: Protti
authors: Yvette
authors: Y
authors: Bohraus
authors: Willy
authors: W
authors: Gsell
authors: Peter D
authors: PD
authors: Weinberg
authors: C Ross
authors: CR
authors: Ethier
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000000981:diagnostic imaging / Q000502:physiology*; D001696:Biomechanical Phenomena; D001783:Blood Flow Velocity / Q000502:physiology*; D006439:Hemodynamics / Q000502:physiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D051379:Mice; D008810:Mice, Inbred C57BL; D008954:Models, Biological; D055114:X-Ray Microtomography