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  • 51.
    Selskog, Pernilla
    Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation. Linköping University, The Institute of Technology.
    Kinematics of the heart: strain and strain-rate using time-resolved three-dimensional phase contrast MRI2004Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    During the cardiac cycle, the myocardium (heart muscle) undergoes large elastic deformations as a consequence of the active muscle contraction along the muscle :fibers and their relaxation, respectively. A four-dimensional (4D) description (three spatial dimensions + time) of the kinematics of the myocardium would bring increased understanding of the mechanical properties of the heart and may be of interest in assessing regional myocardial function.

    The heart is a complex three-dimensional structure and therefore velocity components in three directions are necessary to accurately describe the velocities in the myocardium. The phase contrast MRI pulse sequence used in this work provides velocity vectors in a 3D spatial grid covering the entire heart throughout the cardiac cycle. The suggested method provides the strain-rate tensor in each measured voxel and time frame of the cardiac cycle, calculated from the velocity field. Coordinates for the measured voxels,obtained from the velocity data, defme the deformation of a finite element mesh. This mesh is used for calculation of myocardial strain.

    The method presented in this thesis enables automated delineation of the borders of the myocardium, definition of a parametric fmite element mesh and calculation of 4D myocardial strain and strain-rate throughout the cardiac cycle. The suggested visualization method displays the full tensors, including the main direction of deformation or deformation rate without any assumptions of myocardial motion directions in the calculations.

    List of papers
    1. Kinematics of the heart: strain-rate imaging from time-resolved three-dimensional phase contrast MRI
    Open this publication in new window or tab >>Kinematics of the heart: strain-rate imaging from time-resolved three-dimensional phase contrast MRI
    Show others...
    2002 (English)In: IEEE Transactions on Medical Imaging, ISSN 0278-0062, E-ISSN 1558-254X, Vol. 21, no 9, p. 1105-1109Article in journal (Refereed) Published
    Abstract [en]

    A four-dimensional mapping (three spatial dimensions + time) of myocardial strain-rate would help to describe the mechanical properties of the myocardium, which affect important physiological factors such as the pumping performance of the ventricles. Strain-rate represents the local instantaneous deformation of the myocardium and can be calculated from the spatial gradients of the velocity field. Strain-rate has previously been calculated using one-dimensional (ultrasound) or two-dimensional (2-D) magnetic resonance imaging techniques. However, this assumes that myocardial motion only occurs in one direction or in one plane, respectively. This paper presents a method for calculation of the time-resolved three-dimensional (3-D) strain-rate tensor using velocity vector information in a 3-D spatial grid during the whole cardiac cycle. The strain-rate tensor provides full information of both magnitude and direction of the instantaneous deformation of the myocardium. A method for visualization of the full 3-D tensor is also suggested. The tensors are visualized using ellipsoids, which display the principal directions of strain-rate and the ratio between strain-rate magnitude in each direction. The presented method reveals the principal strain-rate directions without a priori knowledge of myocardial motion directions.

    National Category
    Medical and Health Sciences
    Identifiers
    urn:nbn:se:liu:diva-26711 (URN)10.1109/TMI.2002.804431 (DOI)11305 (Local ID)11305 (Archive number)11305 (OAI)
    Available from: 2009-10-08 Created: 2009-10-08 Last updated: 2018-07-03
    2. Kinematics of the Heart: Finite Element and 3D Time-Resolved Phase Contrast Magnetic resonance Imaging
    Open this publication in new window or tab >>Kinematics of the Heart: Finite Element and 3D Time-Resolved Phase Contrast Magnetic resonance Imaging
    Show others...
    2002 (English)In: Proceedings of 9th Workshop on The Finite Element Method in Biomedical Engineering, Biomechanics and Related Fields, 2002Conference paper, Published paper (Refereed)
    Abstract [en]

    The complex three-dimensional structure of the heart muscle (myocardium) has anisotropic, non-linear and time-dependent mechanical properties. During the cardiac cycle, the myocardium undergoes large elastic deformations as a consequence of the active muscle contraction along the muscle fibers and their relaxation, respectively. A four-dimensional (4D) description (three spatial dimensions + time) of the mechanical properties of the myocardium would be of interest in the assessment of myocardial function. Time-resolved 3D phase contrast MRI makes it possible to quantify all three velocity components, which is necessary to as accurately as possible describe the velocities in the heart. The velocity data may be used for investigation of the deformation of the heart and calculation of strain in the myocardial wall. We present a method for estimation of myocardial kinematics using finite elements and 3D time-resolved phase contrast MRI.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-62681 (URN)
    Conference
    9th 9th Workshop on The Finite Element Method in Biomedical Engineering, Biomechanics and Related Fields. University of Ulm, Germany, 18-19 July.
    Available from: 2010-12-02 Created: 2010-12-02 Last updated: 2013-11-25
  • 52.
    Selskog, Pernilla
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Heiberg, Einar
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology.
    Quantification of myocardial strain-rate from 3D Cine phase contrast2000In: ESMRMB,2000, 2000Conference paper (Other academic)
  • 53.
    Selskog, Pernilla
    et al.
    Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation. Linköping University, The Institute of Technology.
    Torstenfelt, Bo
    Linköping University, Department of Management and Engineering, Solid Mechanics. Linköping University, The Institute of Technology.
    Ebbers, Tino
    Linköping University, Department of Medicine and Care. Linköping University, Faculty of Health Sciences.
    Wigström, Lars
    Linköping University, Department of Medicine and Care. Linköping University, Faculty of Health Sciences.
    Karlsson, M.
    Linköping University, Department of Biomedical Engineering. Linköping University, The Institute of Technology.
    Kinematics of the Heart: Finite Element and 3D Time-Resolved Phase Contrast Magnetic resonance Imaging2002In: Proceedings of 9th Workshop on The Finite Element Method in Biomedical Engineering, Biomechanics and Related Fields, 2002Conference paper (Refereed)
    Abstract [en]

    The complex three-dimensional structure of the heart muscle (myocardium) has anisotropic, non-linear and time-dependent mechanical properties. During the cardiac cycle, the myocardium undergoes large elastic deformations as a consequence of the active muscle contraction along the muscle fibers and their relaxation, respectively. A four-dimensional (4D) description (three spatial dimensions + time) of the mechanical properties of the myocardium would be of interest in the assessment of myocardial function. Time-resolved 3D phase contrast MRI makes it possible to quantify all three velocity components, which is necessary to as accurately as possible describe the velocities in the heart. The velocity data may be used for investigation of the deformation of the heart and calculation of strain in the myocardial wall. We present a method for estimation of myocardial kinematics using finite elements and 3D time-resolved phase contrast MRI.

  • 54. Storck, K
    et al.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Ask, Per
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Heat transfer simulation in the evaluation of the nasal thermistor technique1996In: IEEE Transactions on Biomedical Engineering, ISSN 0018-9294, E-ISSN 1558-2531, Vol. 43, p. 1187-1191Article in journal (Refereed)
  • 55.
    Svensson, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Gårdhagen, Roland
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Comparison of flow parameters between different geometries of a human aorta with coarctation and aneurysm2005In: 2005 Summer Bioengineering Conference,2005, Vail, USA: Summer Bioengineering Conference Committee , 2005Conference paper (Refereed)
  • 56.
    Svensson, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Gårdhagen, Roland
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Geometrical Influence on CFD Analysis of Human Aorta2004Report (Other academic)
  • 57.
    Svensson, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Gårdhagen, Roland
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Patient Specific Human Aorta Geometry Influence on CFD Simulation Parameters2004In: 17th Nordic Seminar on Computational Mechanics NSCM17,2004, 2004Conference paper (Refereed)
  • 58.
    Svensson, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Gårdhagen, Roland
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Wall Back Flow Variations During Pulsative Flow in a Human Aorta2005In: Svenska Mekanikdagar 2005,2005, 2005, p. 61-62Conference paper (Refereed)
  • 59.
    Svensson, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Gårdhagen, Roland
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Wall back flow in human aorta: influence of geometry2005In: NBC05 Umeå,2005, Umeå: Int'l federation for medical anc Biological Engineering IFMBE , 2005, p. 85-Conference paper (Refereed)
  • 60.
    Svensson (Renner), Johan
    et al.
    Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Gårdhagen, Roland
    Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Heiberg, Einar
    Department of Clinical Physiology, Lund University, Sweden.
    Ebbers, Tino
    Linköping University, Department of Medicine and Care. Linköping University, Faculty of Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Loyd, Dan
    Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics. Linköping University, The Institute of Technology.
    Länne, Toste
    Linköping University, Department of Medicine and Care, Physiology. Linköping University, Faculty of Health Sciences. Linköping University, Center for Medical Image Science and Visualization (CMIV). Östergötlands Läns Landsting, Heart Centre, Department of Thoracic and Vascular Surgery.
    Karlsson, Matts
    Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation. Linköping University, The Institute of Technology. Linköping University, Center for Medical Image Science and Visualization (CMIV).
    Feasibility of Patient Specific Aortic Blood Flow CFD Simulation2006In: Medical Image Computing and Computer-Assisted Intervention – MICCAI 2006: 9th International Conference, Copenhagen, Denmark, October 1-6, 2006. Proceedings, Part I / [ed] Rasmus Larsen, Mads Nielsen and Jon Sporring, Springer Berlin/Heidelberg, 2006, 1, Vol. 4190, p. 257-263Conference paper (Refereed)
    Abstract [en]

    Patient specific modelling of the blood flow through the human aorta is performed using computational fluid dynamics (CFD) and magnetic resonance imaging (MRI). Velocity patterns are compared between computer simulations and measurements. The workflow includes several steps: MRI measurement to obtain both geometry and velocity, an automatic levelset segmentation followed by meshing of the geometrical model and CFD setup to perform the simulations follwed by the actual simulations. The computational results agree well with the measured data.

  • 61. Tibayan, Frederick A.
    et al.
    Rodriguez, Filiberto
    Langer, Frank
    Zasio, Mary K.
    Bailey, Lynn
    Liang, David
    Daughters, George T
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation.
    Ingels, Neil B.
    Miller, Craig
    Increases in mitral leaflet radii of curvature with chronic ischemic mitral regurgitation2004In: Journal of Heart Valve Disease, ISSN 0966-8519, E-ISSN 2053-2644, Vol. 13, no 5, p. 772-778Article in journal (Refereed)
  • 62.
    Wigström, Lars
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Ebbers, Tino
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Fyrenius, Anna
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Engvall, Jan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Wranne, Bengt
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    Bolger, Ann F
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Clinical Physiology. Östergötlands Läns Landsting, Heart Centre, Department of Clinical Physiology.
    The effects of maxwell terms on particle traces calculated from 3D cine phase contrast images1999In: Journal of Cardiovascular Magnetic Resonance,1999, 1999, p. 93-93Conference paper (Other academic)
  • 63.
    Wren, Joakim
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation.
    heat transfer analysis model of microwave thermal therapy of the prostate2000In: World Congress on Medical Physics and Biomedical Engineering,2000, 2000Conference paper (Refereed)
  • 64.
    Wren, Joakim
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    A hybrid equation for simulation of perfused tissue during thermal treatment2001In: International Journal of Hyperthermia, ISSN 0265-6736, E-ISSN 1464-5157, Vol. 17, no 6, p. 483-498Article in journal (Refereed)
    Abstract [en]

    Bio-heat equations (BHEs) are necessary for predicting tissue temperature during thermal treatment. For some applications, however, existing BHEs describe the convective heat transfer by the blood perfusion in an unsatisfactory way. The two most frequently used equations, the BHE of Pennes and the keff equation, use for instance either a heat sink or an increased thermal conductivity in order to account for the blood perfusion. Both these methods introduce modelling inaccuracies when applied to an ordinary tissue continuum with a variety of vessel sizes. In this study, a hybrid equation that includes both an increased thermal conductivity and a heat sink is proposed. The equation relies on the different thermal characteristics associated with small, intermediate and large sized vessels together with the possibilities of modelling these vessels using an effective thermal conductivity in combination with a heat sink. The relative importance of these two terms is accounted for by a coefficient ▀. For ▀ = 0 and ▀ = 1, the hybrid equation coincides with the BHE of Pennes and the keff equation, respectively. The hybrid equation is used here in order to simulate temperature fields for two tissue models. The temperature field is greatly affected by ▀, and the effect is dependent on, e.g. the boundary conditions and the power supply. Since the BHE of Pennes and the keff equation are included in the hybrid equation, this equation can also be useful for evaluation of the included equations. Both these heat transfer modes are included in the proposed equation, which enables implementation in standard thermal simulation programmes.

  • 65.
    Wren, Joakim
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Transient temperature response of the myocardium investigated by the hybrid bioheat model2004In: IASME Transactions, ISSN 1790-031X, Vol. 1, no 3, p. 560-565Article in journal (Refereed)
  • 66.
    Wren, Joakim
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Loyd, Dan
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Applied Thermodynamics and Fluid Mechanics.
    Karlsson, Matts
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation .
    Investigation of medical thermal treatment using a hybrid bio-heat model2004In: 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society,2004, 2004Conference paper (Refereed)
12 51 - 66 of 66
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