Parallel Excitation Experiments Using a Novel Direct Calibration Technique for RF-Pulse Determination

Introduction: The concept of Parallel Excitation or Transmit SENSE [1-6] has shown its potential to reduce several problems of single channel excitation, e. g. offresonance or transverse relaxation effects, due to its pulse shortening capabilities. However, despite the shorter pulse lengths these deficiencies cannot be compensated completely. In this study a convenient and very general approach to determine Parallel Excitation pulses is presented, which not only further reduces the mentioned effects but also inherently compensates for other experimental imperfections, such as deviations of the real k-space trajectory from the desired one. Experiments of B1inhomogeneity compensation and inner volume excitation in a phantom and in a fixed rat demonstrate the feasibility of this approach.