title: Cardiac Shear Wave Velocity Detection in the Porcine Heart.
abstract: Cardiac muscle stiffness can potentially be estimated non-invasively with shear wave elastography. Shear waves are present on the septal wall after mitral and aortic valve closure, thus providing an opportunity to assess stiffness in early systole and early diastole. We report on the shear wave recordings of 22 minipigs with high-frame-rate echocardiography. The waves were captured with 4000 frames/s using a programmable commercial ultrasound machine. The wave pattern was extracted from the data through a local tissue velocity estimator based on one-lag autocorrelation. The wave propagation velocity was determined with a normalized Radon transform, resulting in median wave propagation velocities of 2.2 m/s after mitral valve closure and 4.2 m/s after aortic valve closure. Overall the velocities ranged between 0.8 and 6.3 m/s in a 95% confidence interval. By dispersion analysis we found that the propagation velocity only mildly increased with shear wave frequency.
authors.affiliation: Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands; Acoustical Wavefield Imaging, Delft University of Technology, Delft, The Netherlands. Electronic address: h.vos@erasmusmc.nl.
authors.forename: Hendrik J
authors.initials: HJ
authors.lastname: Vos
authors.affiliation: Cardiology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Bas M
authors.initials: BM
authors.lastname: van Dalen
authors.affiliation: Experimental Cardiology, Erasmus MC, Rotterdam, The Netherlands; University of Turku and Turku University Hospital, Turku, Finland; Department of Clinical Physiology and Nuclear Medicine, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Heinonen
authors.affiliation: Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Johan G
authors.initials: JG
authors.lastname: Bosch
authors.affiliation: Experimental Cardiology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Oana
authors.initials: O
authors.lastname: Sorop
authors.affiliation: Experimental Cardiology, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Duncker
authors.affiliation: Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands; Acoustical Wavefield Imaging, Delft University of Technology, Delft, The Netherlands; Netherlands Heart Institute, Utrecht, The Netherlands; Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China.
authors.forename: Antonius F W
authors.initials: AF
authors.lastname: van der Steen
authors.affiliation: Biomedical Engineering, Erasmus MC, Rotterdam, The Netherlands; Acoustical Wavefield Imaging, Delft University of Technology, Delft, The Netherlands; Department of Clinical Physiology and Nuclear Medicine, University of Turku and Turku University Hospital, Turku, Finland.
authors.forename: Nico
authors.initials: N
authors.lastname: de Jong
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity / Q000502:physiology; D004452:Echocardiography / Q000379:methods*; D006321:Heart / Q000000981:diagnostic imaging / Q000502:physiology*; D023421:Models, Animal; D015203:Reproducibility of Results; D013552:Swine
keywords: Echocardiography; High-frame-rate imaging; Shear wave elastography; Stiffness measurements; Valve closure