title: Sparsity and Biomechanics Inspired Integration of Shape and Speckle Tracking for Cardiac Deformation Analysis.
abstract: Cardiac motion analysis, particularly of the left ventricle (LV), can provide valuable information regarding the functional state of the heart. We propose a strategy of combining shape tracking and speckle tracking based displacements to calculate the dense deformation field of the myocardium. We introduce the use and effects ofl1regularization, which induces sparsity, in our integration method. We also introduce regularization to make the dense fields more adhering to cardiac biomechanics. Finally, we motivate the necessity of temporal coherence in the dense fields and demonstrate a way of doing so. We test our method on ultrasound (US) images acquired from six open-chested canine hearts. Baseline and post-occlusion strain results are presented for an animal, where we were able to detect significant change in the ischemic region. Six sets of strain results were also compared to strains obtained from tagged magnetic resonance (MR) data. Median correlation (with MR-tagging) coefficients of 0.73 and 0.82 were obtained for radial and circumferential strains respectively.
authors.affiliation: Departments of Electrical Engineering, Yale University, New Haven, CT, USA.
authors.forename: Nripesh
authors.initials: N
authors.lastname: Parajuli
authors.affiliation: IBM Research-Almaden, San Jose, CA, USA.
authors.forename: Colin B
authors.initials: CB
authors.lastname: Compas
authors.affiliation: Departments of Internal Medicine, Yale University, New Haven, CT, USA.
authors.forename: Ben A
authors.initials: BA
authors.lastname: Lin
authors.affiliation: Merck Sharp and Dohme, Singapore, Republic of Singapore.
authors.forename: Smita
authors.initials: S
authors.lastname: Sampath
authors.affiliation: Department of Bioengineering, University of Washington, Seattle, WA, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: O'Donnell
authors.affiliation: Departments of Internal Medicine, Yale University, New Haven, CT, USA; Departments of Diagnostic Radiology, Yale University, New Haven, CT, USA.
authors.forename: Albert J
authors.initials: AJ
authors.lastname: Sinusas
authors.affiliation: Departments of Electrical Engineering, Yale University, New Haven, CT, USA; Departments of Biomedical Engineering, Yale University, New Haven, CT, USA; Departments of Diagnostic Radiology, Yale University, New Haven, CT, USA.
authors.forename: James S
authors.initials: JS
authors.lastname: Duncan
keywords: Echocardiography; Motion; Radial basis functions; Regularization; Shape tracking; Speckle tracking