Combination of Basic and Tailored RF Shimming Using Curved Spoke Trajectories

Ulrich Katscher¹, Peter Brnert¹

Generally, two RF shimming approaches are reported. The first approach, "basic" RF shimming via adjusting the channels drive weights, is stable and fast, however, has limited shimming potential. The second approach, "tailored" RF shimming via multidimensional RF pulses, is more complex and requires significant sequence modifications, however, has superior shimming potential. This study investigates a compromise combining the advantages of both approaches. It applies a slight curvature of the "straight" k-space trajectory of standard slice selective excitation, maintaining short pulse durations, and sharp slice profiles. Simultaneously, it allows higher freedom for in-plane B1 variation, yielding an enhanced shimming potential.