%0 Journal Article %T Sparse parallel transmission on randomly perturbed spiral k-space trajectory %A Pang, Yong %A Jiang, Xiaohua %A Zhang, Xiaoliang %J Quantitative Imaging in Medicine and Surgery %D 2014 %B 2014 %9 %! Sparse parallel transmission on randomly perturbed spiral k-space trajectory %K %X Combination of parallel transmission and sparse pulse is able to shorten the excitation by using both the coil sensitivity and sparse k-space, showing improved fast excitation capability over the use of parallel transmission alone. However, to design an optimal k-space trajectory for sparse parallel transmission is a challenging task. In this work, a randomly perturbed sparse k-space trajectory is designed by modifying the path of a spiral trajectory along the sparse k-space data, and the sparse parallel transmission RF pulses are subsequently designed based on this optimal trajectory. This method combines the parallel transmission and sparse spiral k-space trajectory, potentially to further reduce the RF transmission time. Bloch simulation of 90° excitation by using a four channel coil array is performed to demonstrate its feasibility. Excitation performance of the sparse parallel transmission technique at different reduction factors of 1, 2, and 4 is evaluated. For comparison, parallel excitation using regular spiral trajectory is performed. The passband errors of the excitation profiles of each transmission are calculated for quantitative assessment of the proposed excitation method. %U https://qims.amegroups.org/article/view/3730 %V 4 %N 2 %P 106-111 %@ 2223-4306