Modeling of cardiac motion using wavelets: comparison with Fourier-based models

In this paper, a 4-D parametric model based on wavelets is applied to the representation of the shape and motion of myocardial surfaces. It is qualitatively, and quantitatively evaluated on multi-phase cardiac MRI data and compared with the previously presented 4-D Fourier-based model. The wavelet-based model uses a number of boundary points, extracted from the imaging data, as samples on which a moving 3-D surface is fitted. The resulting model is continuous and smooth and provides a full description of cardiac motion in 3-D, from which measurements for quantitative motion analysis can be derived. Application results showed that the localized and multi-resolution nature of wavelets allowed more accurate representation of cardiac shape and motion than the Fourier model, especially regarding shape details and fast deformation, while the Fourier model provided a smoother surface, more robust to noisy data.