title: Influence of ultrasound speckle tracking strategies for motion and strain estimation.
abstract: Speckle Tracking is one of the most prominent techniques used to estimate the regional movement of the heart based on ultrasound acquisitions. Many different approaches have been proposed, proving their suitability to obtain quantitative and qualitative information regarding myocardial deformation, motion and function assessment. New proposals to improve the basic algorithm usually focus on one of these three steps: (1) the similarity measure between images and the speckle model; (2) the transformation model, i.e. the type of motion considered between images; (3) the optimization strategies, such as the use of different optimization techniques in the transformation step or the inclusion of structural information. While many contributions have shown their good performance independently, it is not always clear how they perform when integrated in a whole pipeline. Every step will have a degree of influence over the following and hence over the final result. Thus, a Speckle Tracking pipeline must be analyzed as a whole when developing novel methods, since improvements in a particular step might be undermined by the choices taken in further steps. This work presents two main contributions: (1) We provide a complete analysis of the influence of the different steps in a Speckle Tracking pipeline over the motion and strain estimation accuracy. (2) The study proposes a methodology for the analysis of Speckle Tracking systems specifically designed to provide an easy and systematic way to include other strategies. We close the analysis with some conclusions and recommendations that can be used as an orientation of the degree of influence of the models for speckle, the transformation models, interpolation schemes and optimization strategies over the estimation of motion features. They can be further use to evaluate and design new strategy into a Speckle Tracking system.
authors.affiliation: Consejo Nacional de Investigaciones Científicas y Técnicas, FCEN, Universidad Nacional de Cuyo, Padre Jorge Contreras 1300, 5500 Mendoza, Argentina; Departamento de Física Médica, Centro Atómico Bariloche, Avenida Bustillo 9500, 8400 S. C. de Bariloche, RN, Argentina; Fundación Escuela Medicina Nuclear, Garibaldi 405. 5500, Mendoza, Argentina; Laboratorio de Procesado de Imagen (LPI), E.T.S. Ingenieros de Telecomunicación, Universidad de Valladolid, Valladolid, Spain. Electronic address: acuriale@fcen.uncu.edu.ar.
authors.forename: Ariel H
authors.initials: AH
authors.lastname: Curiale
authors.affiliation: Applied Chest Imaging Laboratory (ACIL), Brigham and Women's Hospital, Harvard Medical School, 1249 Boylston St. 02115, Boston, MA, USA; Biomedical Image Technologies Laboratory (BIT), ETSI Telecomunicacion, Universidad Politecnica de Madrid, and CIBER-BBN, Avenida Complutense 30, 28040, Madrid, Spain.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Vegas-Sánchez-Ferrero
authors.affiliation: Laboratorio de Procesado de Imagen (LPI), E.T.S. Ingenieros de Telecomunicación, Universidad de Valladolid, Valladolid, Spain.
authors.forename: Santiago
authors.initials: S
authors.lastname: Aja-Fernández
mesh_terms: D000465:Algorithms; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D009038:Motion; D009068:Movement; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*
keywords: Demons registration; Diffeomorphic registration; Echocardiography; Generalized gamma; Local correlation; Maximum likelihood; Mixture model; Optical flow; Speckle model; Speckle tracking; Strain estimation; Ultrasound images