Large Tip Angle Parallel Excitation Using Nonlinear Non-Bijective PatLoc Encoding Fields

Martin Haas¹, Peter Ullmann², Johannes T. Schneider, ^1,2, Wolfgang Ruhm², Jrgen Hennig¹, Maxim Zaitsev¹

The nonlinear non-bijective "PatLoc" fields recently proposed for anatomically tailored readout encoding are examined in combination with RF transmission for 2D spatially selective excitation. It is shown that parallel transmission is necessary to resolve encoding ambiguities but that PatLoc encoding allows for higher resolution magnetization patterns to be generated locally as compared to conventional linear encoding fields. The RF pulse design is based on the optimal control algorithm introduced by D. Xu et al. MRM 59, 547 (2008), which has been generalized to the regime of nonlinear non-bijective encoding fields.