Using Dedicated Fieldprobes for Trajectory Measurements in Parallel Excitation Experiments

Johannes Thomas Schneider¹, Christoph Barmet², Wolfgang Ruhm¹, Klaas Paul Pruessmann², Peter Ullmann¹

Several studies have demonstrated the benefit of measuring actually traversed k-space trajectories and incorporating this information into the design process of parallel spatially-selective excitation (PEX) pulses. However, most of the applied measurement techniques are based on phase evolutions in situ within the object. This leads to a strong dependency of data-quality and -reliability on the imaged objects. To overcome these limitations, a newly developed D2O-fieldprobe was used in this study in order to acquire object-independent trajectory data. This allows robust measurements of calibration data for the calculation of PEX pulses and results in high excitation accuracy under various experimental conditions.