title: Quantification of 3-D regional myocardial deformation: shape-based analysis of magnetic resonance images.
abstract: A comprehensive three-dimensional (3-D) shape-based approach for quantification of regional myocardial deformations was evaluated in a canine model (n = 8 dogs) with the use of cine magnetic resonance imaging. The shape of the endocardial and epicardial surfaces was used to track the 3-D trajectories of a dense field of points over the cardiac cycle. The shape-based surface displacements are integrated with a continuum biomechanics model incorporating myofiber architecture to estimate both cardiac- and fiber-specific endocardial and epicardial strains and shears for 24 left ventricular regions. Whereas radial and circumferential end-systolic strains were fairly uniform, there was a significant apex-to-base gradient in longitudinal strain and radial-longitudinal shear. We also observed transmural epicardial-to-endocardial gradients in both cardiac- and fiber-specific strains. The increase in endocardial strain was accompanied by increases in radial-longitudinal shear and radial-fiber shears in the endocardium, supporting previous theories of regional myocardial deformation that predict considerable sliding between myocardial fibers.
authors.affiliation: Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520-8042, USA. albert.sinusas@yale.edu
authors.forename: A J
authors.initials: AJ
authors.lastname: Sinusas
authors.forename: X
authors.initials: X
authors.lastname: Papademetris
authors.forename: R T
authors.initials: RT
authors.lastname: Constable
authors.forename: D P
authors.initials: DP
authors.lastname: Dione
authors.forename: M D
authors.initials: MD
authors.lastname: Slade
authors.forename: P
authors.initials: P
authors.lastname: Shi
authors.forename: J S
authors.initials: JS
authors.lastname: Duncan
mesh_terms: D000818:Animals; D004285:Dogs; D006321:Heart / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D009200:Myocardial Contraction