Blaimer Martin, Gutberlet Marcel, Kellman Peter, Breuer Felix A, Köstler Herbert, Griswold Mark A
Department of Radiology, University Hospitals of Cleveland, Case Western Reserve University, Cleveland, Ohio, USA.
Magn Reson Med. 2009 Jan;61(1):93-102. doi: 10.1002/mrm.21652.
A new approach for utilizing conjugate k-space symmetry for improved parallel MRI performance is presented. By generating virtual coils containing conjugate symmetric k-space signals from actual coils, additional image- and coil-phase information can be incorporated into the reconstruction process for parallel acquisition techniques. In that way the reconstruction conditions are improved, resulting in less noise enhancement. In particular in combination with generalized autocalibrating partially parallel acquisitions (GRAPPA), the virtual coil concept represents a practical approach since no explicit spatial phase information is required. In addition, the influence of phase variations originating from the complex receiver coils as well as from the background is investigated. It is shown that there exist background phase distributions yielding an optimized pMRI reconstruction.
提出了一种利用共轭k空间对称性来提高并行MRI性能的新方法。通过从实际线圈生成包含共轭对称k空间信号的虚拟线圈，可以将额外的图像和线圈相位信息纳入并行采集技术的重建过程。这样可以改善重建条件，减少噪声增强。特别是与广义自校准部分并行采集（GRAPPA）相结合时，虚拟线圈概念是一种实用的方法，因为不需要明确的空间相位信息。此外，还研究了源自复杂接收线圈以及背景的相位变化的影响。结果表明，存在能产生优化的并行MRI重建的背景相位分布。
