Motion artifact is a serious problem to MRI diagnosis and analysis due to periodic motion or patient motion during the image acquisition. A metric-based method, EXTRACT, used the information by using extrapolation of the k-space data and a metric based on correlation between the extrapolated k-space data and the motion corrupted k-space data. In this paper, we propose to use the finite support technique in conjunction with the generalized series in the spectral extrapolation to determine the motion that causes phase shift in the corrupted k-space data, thus improving the performance of MRI motion correction. Some experimental results are given to demonstrate the performance of the proposed algorithm.