Joint Design of Excitation and Refocusing Pulses for Fast Spin Echo Sequences in Parallel Transmission

Dan Xu¹, Kevin F. King¹

Parallel transmission of RF pulses has been shown to be effective in correcting B1 inhomogeneity. However, there has been no fast spin echo application with parallel transmission yet due to the lack of ways of designing parallel transmit pulses that satisfy the CPMG condition. We pose the design of excitation and refocusing pulse pair as a joint design problem under the optimal control framework, where the optimal pulse pair is sought jointly to drive the magnetization vector to its desired state while maintaining the CPMG condition. Bloch simulation results are shown to demonstrate the superior performance of the proposed method.