Elastically deformable model-based motion-tracking of left ventricle

The motion of the myocardium is a sensitive indicator of many types of heart disease. Quantitative characterization of this motion is essential for the accurate diagnosis and treatment of heart disease. Although several magnetic resonance imaging (MRI) techniques, such as tagged MRI and phase contrast MRI, provide noninvasive tools to obtain correlation of the position of points within the myocardium between images taken at subsequent time phases, the accurate tracking of the movement of these points remains a challenge due to the relatively low out-of-plane resolution of these imaging techniques. A motion tracking method based on elastic deformation estimation of a deformable model has been developed to track the three-dimensional motion of the myocardium. Elastic deformation estimation is performed on phase contrast MRI data by balancing the deformation potential energy of a deformable model and the potential energy derived from integrating velocity values of myocardial tissue points. The advantage of this method is that it can provide a physically plausible yet computationally efficient framework for cardiac motion tracking. To assess the proposed method, the motion of a normal human left ventricle (LV) was tracked throughout the entire cardiac cycle, and a quantitative strain analysis of the motion of the LV was carried out from end diastole to end systole. The results showed that the strain measurements were generally found to be consistent with previously published values.