Direct Method for Parallel Transmit Pulse Design by Time-Reversal of the Small-Tip Angle Excitation

Kaveh Vahedipour¹, N. Jon Shah¹, ², Tony Jon Stcker¹

This abstract demonstrates that the spatio-temporal symmetries fundamental to the Bloch equation and the principle of reciprocity allow one to utilise MR signal acquisition or simulation for small tip-angle pulse design. Furthermore, it is demonstrated how the method is intrinsically capable of parallel transmit as well as how mitigation of static and high frequency field inhomogeneities is intuitively performed. The system-encoding matrix is never considered in theory or algorithmically. A theoretical derivation is formulated and proven in principle. It is further demonstrated that the MRI experiment can be used directly as an analogue computer for small tip-angle pulses.