Feng Shuo, Ji Jim
Department of Electrical and Computer Engineering, Texas A&M University, College Station, TX 77843-3128, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2010;2010:3313-6. doi: 10.1109/IEMBS.2010.5627495.
Parallel excitation using coil array has been introduced in MRI as an effective method to design multi-dimensional spatially selective RF pulses. Generally, all transmit coil elements are used simultaneously in parallel excitation. In case of large array, RF pulse design requires significant computation time and memory size. In this paper, a method using reduced number of coils for parallel excitation is proposed to take advantage of localized coil transmit sensitivity in large array. Specifically, a subset of coils in the large array can be selected based on coil sensitivity coverage and desired excitation pattern. Simulation results with both spiral and EPI k-space trajectories show that proposed method is effective in achieving high excitation resolution at different acceleration factors while the computation time and memory requirement are greatly reduced.
使用线圈阵列的并行激励已被引入磁共振成像（MRI）中，作为设计多维空间选择性射频脉冲的有效方法。通常，在并行激励中所有发射线圈元件同时使用。对于大型阵列，射频脉冲设计需要大量的计算时间和内存大小。本文提出了一种使用减少数量的线圈进行并行激励的方法，以利用大型阵列中局部线圈的发射灵敏度。具体而言，可以基于线圈灵敏度覆盖范围和所需的激励模式来选择大型阵列中的线圈子集。使用螺旋和回波平面成像（EPI）k空间轨迹的仿真结果表明，该方法在不同加速因子下有效实现高激励分辨率，同时计算时间和内存需求大大降低。
