liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Kinematics of the heart: strain and strain-rate using time-resolved three-dimensional phase contrast MRI
Linköping University, Department of Biomedical Engineering, Biomedical Modelling and Simulation. Linköping University, The Institute of Technology.
2004 (English)Licentiate 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.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet , 2004. , 44 p.
Series
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1097
Series
LiU-TEK-LIC, 24
National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:liu:diva-33626Local ID: 19661ISBN: 91-7373-970-7 (print)OAI: oai:DiVA.org:liu-33626DiVA: diva2:254449
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2013-11-25
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, 1105-1109 p.Article 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: 2016-03-14
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

Open Access in DiVA

No full text

Authority records BETA

Selskog, Pernilla

Search in DiVA

By author/editor
Selskog, Pernilla
By organisation
Biomedical Modelling and SimulationThe Institute of Technology
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar

isbn
urn-nbn

Altmetric score

isbn
urn-nbn
Total: 81 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf