GRAPPA Reconstruction with Spatially Varying Calibration of Self-Constraint
GRAPPA Reconstruction with Spatially Varying Calibration of Self-Constraint
复制标题
具有空间变化自约束校准的 GRAPPA 重建
DOI：
10.1002/mrm.25496
复制
发表时间：
2015-10-01
影响因子：
3.3
通讯作者：
Feng, Yanqiu
中科院分区：
文献类型：
--
作者：
Xu, Lin;Guo, Li;Feng, Yanqiu
Purpose: To develop and evaluate a novel method of generalized auto-calibrating partially parallel acquisition (GRAPPA) with spatially varying calibration of self-constraint for parallel magnetic resonance imaging (MRI) reconstruction.Theory and Methods: The conventional GRAPPA independently estimates each missing sample with adjacent acquired data over multiple coils, thereby ignoring correlations inside missing data. Self-constrained methods can exploit correlations inside missing data by imposing linear dependence within full neighborhood kernels and showing improved reconstruction compared with GRAPPA. However, self-constraint kernels are currently calibrated by using auto-calibration signals. Thus, they may be suboptimal for reconstructing outer k-space because of spatially varying correlations. This study proposes a novel GRAPPA method with separate self-constraints (SSC-GRAPPA). In this method, the spatially varying self-constraint coefficients are adaptively calibrated by separately exploiting correlations inside missing and acquired data in the outer k-space. Both phantom and in vivo imaging experiments were conducted with retrospective undersampling to evaluate the performance of the proposed method.Results: Compared with GRAPPA and self-constrained GRAPPA, the proposed SSC-GRAPPA generates images with reduced artifacts and noise.Conclusion: The proposed method provides an effective and efficient approach to improve parallel MRI reconstruction, and has potential to benefit routine clinical practice in the future. (C) 2014 Wiley Periodicals, Inc.
