Abstract Imaging velocity is a major factor affecting clinical applications of magnetic resonance(MR) imaging. And an effective solution of reducing scanning time is to under-sample in k-space and reconstruct the image from under-sampled MR signals. In this paper, the impact of under-sampling pattern on reconstruction quality is analyzed and a joint optimization strategy is proposed to update the under-sampling pattern with image reconstruction model in the context of deep-learning. To optimize the non-continuous under-sampling pattern, it is firstly initialized with full-sampling pattern. Then, relatively less important phase-encodings are gradually pruned until the sparsity requirement in k-space is satisfied. And the optimization of k-space under-sampling pattern is conducted alternatively with that of the reconstruction model. Moreover, the relative importance is estimated with the weight by assigning weight to each phase-coding. Experiments demonstrate that the proposed method improves the quality of the reconstructed MR image compared with the proposed method.
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