Dong Chen1,2, Folkmar Bornemann1, Mika W. Vogel2, Yudong Zhu3
1Center for Mathematical Sciences, Technical University of Munich, Munich, Germany; 2Imaging Technologies, GE Global Research Europe, Munich, Germany; 3New York University Langone Medical Center, New York, NY, USA
Conventional 2D target excitation RF pulse design uses pre-determined k-trajectory based on the k positions required by Nyquist theorem. However Nyquist theorem is sufficient but not necessary condition for most practical target profile. Unlike the spatial encoding task in imaging, where the underlying image is unknown, in the case of excitation pulse design the target excitation profile is known a priori. In this work we propose a k space sparsifying method that exploits this prior-knowledge using Adaptive Energy-Threshold, which significantly reduces pulse duration and offers flexible tradeoff between excitation quality and pulse duration. The method was validated in phantom imaging experiments.