title: Computational simulation of carotid stenosis and flow dynamics based on patient ultrasound data - A new tool for risk assessment and surgical planning.
abstract: OBJECTIVE
  There is nowadays extensive experimental and computational investigation on the pathophysiology of atherosclerosis, searching correlations between its focal nature and local hemodynamic environment. The goal of this work is to present a methodology for patient-specific hemodynamics study of the carotid artery bifurcation based on the use of ultrasound (US) morphological and blood flow velocity patient data.
  
  
  METHODS
  Subject-specific studies were performed for two patients, using a developed finite element code. Geometrical models were obtained from the acquisition of longitudinal and sequential cross-sectional ultrasound images and boundary conditions from Doppler velocity measurements at the common carotid artery.
  
  
  RESULTS
  There was a good agreement between ultrasound imaging data and computational simulated results. For a normal and a stenosed carotid bifurcation the velocity, wall shear stress (WSS) and WSS descriptors analysis illustrated the extremely complex hemodynamic behavior along the cardiac cycle. Different patterns were found, associated with morphology and hemodynamic patient-specific conditions. High values of time-averaged WSS (TAWSS) were found at stenosis site and for both patients TAWSS fields presented low values within areas of high oscillating shear index and relative residence time values, corresponding to recirculation zones.
  
  
  CONCLUSIONS
  Simulated hemodynamic parameters were able to capture the disturbed flow conditions in a normal and a stenosed carotid artery bifurcation, which play an important role in the development of local atherosclerotic plaques. Computational simulations based on clinic US might help improving diagnostic and treatment management of carotid atherosclerosis.
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal; Institute of Mechanical Engineering (IDMEC), University of Porto, Porto, Portugal. Electronic address: lcsousa@fe.up.pt.
authors.forename: Luísa C
authors.initials: LC
authors.lastname: Sousa
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal; Institute of Mechanical Engineering (IDMEC), University of Porto, Porto, Portugal.
authors.forename: Catarina F
authors.initials: CF
authors.lastname: Castro
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal; Institute of Mechanical Engineering (IDMEC), University of Porto, Porto, Portugal.
authors.forename: Carlos C
authors.initials: CC
authors.lastname: António
authors.affiliation: Institute of Mechanical Engineering (IDMEC), University of Porto, Porto, Portugal.
authors.forename: Fernando
authors.initials: F
authors.lastname: Sousa
authors.affiliation: Department of Neurology, São João Hospital Centre, Porto, Portugal; Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Rosa
authors.initials: R
authors.lastname: Santos
authors.affiliation: Department of Neurology, São João Hospital Centre, Porto, Portugal; Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Pedro
authors.initials: P
authors.lastname: Castro
authors.affiliation: Department of Neurology, São João Hospital Centre, Porto, Portugal; Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Porto, Portugal.
authors.forename: Elsa
authors.initials: E
authors.lastname: Azevedo
mesh_terms: D001783:Blood Flow Velocity; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D016893:Carotid Stenosis / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery; D003198:Computer Simulation; D018056:Hemorheology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010347:Patient Care Planning; D018570:Risk Assessment; D033081:Shear Strength; D014463:Ultrasonography
keywords: 3D reconstruction and mesh generation; Atherosclerotic plaque; Carotid artery bifurcation; Doppler ultrasound; Stenosis