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Selskog, Pernilla
Publikationer (5 of 5) Visa alla publikationer
Selskog, P. (2004). Kinematics of the heart: strain and strain-rate using time-resolved three-dimensional phase contrast MRI. (Licentiate dissertation). Linköping: Linköpings universitet
Öppna denna publikation i ny flik eller fönster >>Kinematics of the heart: strain and strain-rate using time-resolved three-dimensional phase contrast MRI
2004 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
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.

Ort, förlag, år, upplaga, sidor
Linköping: Linköpings universitet, 2004. s. 44
Serie
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1097
Serie
LiU-TEK-LIC ; 24
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-33626 (URN)19661 (Lokalt ID)91-7373-970-7 (ISBN)19661 (Arkivnummer)19661 (OAI)
Tillgänglig från: 2009-10-09 Skapad: 2009-10-09 Senast uppdaterad: 2013-11-25
Selskog, P., Torstenfelt, B., Ebbers, T., Wigström, L. & Karlsson, M. (2002). Kinematics of the Heart: Finite Element and 3D Time-Resolved Phase Contrast Magnetic resonance Imaging. In: Proceedings of 9th Workshop on The Finite Element Method in Biomedical Engineering, Biomechanics and Related Fields: . Paper presented at 9th 9th Workshop on The Finite Element Method in Biomedical Engineering, Biomechanics and Related Fields. University of Ulm, Germany, 18-19 July..
Öppna denna publikation i ny flik eller fönster >>Kinematics of the Heart: Finite Element and 3D Time-Resolved Phase Contrast Magnetic resonance Imaging
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2002 (Engelska)Ingår i: Proceedings of 9th Workshop on The Finite Element Method in Biomedical Engineering, Biomechanics and Related Fields, 2002Konferensbidrag, Publicerat paper (Refereegranskat)
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.

Nationell ämneskategori
Teknik och teknologier
Identifikatorer
urn:nbn:se:liu:diva-62681 (URN)
Konferens
9th 9th Workshop on The Finite Element Method in Biomedical Engineering, Biomechanics and Related Fields. University of Ulm, Germany, 18-19 July.
Tillgänglig från: 2010-12-02 Skapad: 2010-12-02 Senast uppdaterad: 2013-11-25
Selskog, P., Heiberg, E., Ebbers, T., Wigström, L. & Karlsson, M. (2002). Kinematics of the heart: strain-rate imaging from time-resolved three-dimensional phase contrast MRI. IEEE Transactions on Medical Imaging, 21(9), 1105-1109
Öppna denna publikation i ny flik eller fönster >>Kinematics of the heart: strain-rate imaging from time-resolved three-dimensional phase contrast MRI
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2002 (Engelska)Ingår i: IEEE Transactions on Medical Imaging, ISSN 0278-0062, E-ISSN 1558-254X, Vol. 21, nr 9, s. 1105-1109Artikel i tidskrift (Refereegranskat) 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.

Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-26711 (URN)10.1109/TMI.2002.804431 (DOI)11305 (Lokalt ID)11305 (Arkivnummer)11305 (OAI)
Tillgänglig från: 2009-10-08 Skapad: 2009-10-08 Senast uppdaterad: 2018-07-03
Selskog, P., Brandt, E., Wigström, L. & Karlsson, M. (2001). Quantification and Visualization of myocardial strain-rate tensors from time-resolved 3D cine phase contrast MRI.. In: Proc. Intl. Soc. Mag. Reson. Med.,2001 (pp. 1870-1870).
Öppna denna publikation i ny flik eller fönster >>Quantification and Visualization of myocardial strain-rate tensors from time-resolved 3D cine phase contrast MRI.
2001 (Engelska)Ingår i: Proc. Intl. Soc. Mag. Reson. Med.,2001, 2001, s. 1870-1870Konferensbidrag, Publicerat paper (Refereegranskat)
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-26728 (URN)11322 (Lokalt ID)11322 (Arkivnummer)11322 (OAI)
Tillgänglig från: 2009-10-08 Skapad: 2009-10-08 Senast uppdaterad: 2016-03-14
Selskog, P. & Heiberg, E. (2000). Quantification of myocardial strain-rate from 3D Cine phase contrast. In: ESMRMB,2000.
Öppna denna publikation i ny flik eller fönster >>Quantification of myocardial strain-rate from 3D Cine phase contrast
2000 (Engelska)Ingår i: ESMRMB,2000, 2000Konferensbidrag, Publicerat paper (Övrigt vetenskapligt)
Nationell ämneskategori
Medicin och hälsovetenskap
Identifikatorer
urn:nbn:se:liu:diva-32999 (URN)18958 (Lokalt ID)18958 (Arkivnummer)18958 (OAI)
Tillgänglig från: 2009-10-09 Skapad: 2009-10-09
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