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Design of multidimensional Shinnar–Le Roux radiofrequency pulses
Author(s) -
Ma Chao,
Liang ZhiPei
Publication year - 2015
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.25179
Subject(s) - planar , excitation , ripple , polynomial , algorithm , compensation (psychology) , computer science , mathematics , mathematical optimization , mathematical analysis , physics , psychology , computer graphics (images) , quantum mechanics , voltage , psychoanalysis
Purpose To generalize the conventional Shinnar–Le Roux method for the design of multidimensional radiofrequency pulses. Methods Using echo‐planar gradients, the multidimensional radiofrequency pulse design problem was converted into a series of one‐dimensional polynomial design problems. Each of the one‐dimensional polynomial design problems was solved efficiently. B 0 inhomogeneity compensation and design of spatial‐spectral pulses were also considered. Results The proposed method was used to design two‐dimensional excitation and refocusing pulses. The results were validated through Bloch equation simulation and experiments on a 3.0 T scanner. Large‐tip‐angle, equiripple‐error, multidimensional excitation was achieved with ripple levels closely matching the design specifications. Conclusion The conventional Shinnar–Le Roux method can be extended to design multidimensional radiofrequency pulses. The proposed method achieves almost equiripple excitation errors, allows easy control of the tradeoff among design parameters, and is computationally efficient. Magn Reson Med 73:633–645, 2015. © 2014 Wiley Periodicals, Inc.