Experiments in multiresolution motion estimation for multifrequency tagged cardiac MR images

In tagged magnetic resonance imaging of the human heart, diierent frequency patterns can be imposed and imaged as the heart moves. It is advantageous to use low-frequency patterns to improve both image acquisition time and the performance of gradient-based optical ow motion analysis methods. This paper explores the eeects of three factors | image preeltering, multireso-lution optical ow, and multifrequency tag patterns | through a serious of controlled simulation experiments. We show that use of image preeltering in a multires-olution optical ow approach achieves signiicant performance gains, and permits a factor of four reduction in imaging time, without the need for multifrequency tag patterns.