3D selective pulse design with variable spoke trajectories for parallel excitation

Three dimensional spatial selective RF pulse of practical length has been demonstrated using parallel transmission technique in Magnetic Resonance Imaging. Currently, spoke trajectory, which is a set of parallel k-space straight lines, is widely used for 3-D slab excitation to achieve sharp slice profile and a uniform or smoothly varying in-plane profile. The better control of in-plane profile mainly comes from an increased number of spokes. In this paper, we proposed three types of modified spoke trajectories for the 3-D tailored RF pulse design which traverse k-space more efficiently. Simulations are used to characterize the proposed trajectories.