Fast dynamic magnetic resonance imaging based on an improved Motion Estimation/Motion Compensation scheme

摘要

Compressed Sensing (CS) increases the speed of MRI by reducing the sampling data. k-t FOCUSS is an effective CS algorithm for image reconstruction in dynamic MRI. In this method, in order to further improve its performance, a predictive frame is first obtained using the Motion Estimation (ME) and Motion Compensation (MC) algorithms, and the quality of reconstructed images can then be enhanced by the study of sparsity of the residuals based on the improved predictive frame. However, traditional MC algorithm usually causes block artifacts. In this work, an Overlapped Block Motion Compensation (OBMC) scheme was used to overcome this problem. Two reference frames, located at systole and diastole periods, were both acquired to improve the predication accuracy. Experimental results show that, the k-t FOCUSS with ME/MC and OBMC can successfully suppress the image artifacts generated by the standard k-t FOCUSS with ME/MC.