Cem Murat Deniz1,2, Dong Chen3, Leeor Alon2,4, Ryan Brown4, Hans-Peter Fautz5, Daniel K. Sodickson4, Yudong Zhu4
1Center for Biomedical Imaging , Department of Radiology, NYU School of Medicine, New York, NY, United States; 2Sackler Institute of Graduate Biomedical Sciences, NYU School of Medicine, New York, NY, United States; 3Center for Mathematical Science, Technical University of Munich, Munich, Germany; 4Center for Biomedical Imaging, Department of Radiology, NYU School of Medicine, New York, NY, United States; 5Siemens Medical Solutions, Erlangen, Germany
Tailored inner-volume excitation on whole-body scanners is currently limited by long 3D RF pulses. Effective pulse length reduction with parallel transmission requires careful selection of the excitation k-space trajectory. In this work, two methods of determining sparse excitation trajectories were compared for parallel transmit pulse design in the small-tip angle and large-tip-angle regimes: a) an Orthogonal Matching Pursuit (OMP) algorithm, and b) a one-step basic thresholding approach. Good inner-volume excitation with a pulse length of less than 9ms was achieved using an eight-channel transmitter on a whole-body human 7T scanner.