Signe Johanna Vannesj1, Lars Kasper1, Matteo Pavan1, Christoph Barmet1, Klaas Paul Pruessmann1
1Institute for Biomedical Engineering,
ETH and University Zrich,
Susceptibility artefacts is a major problem in MRI, becoming more severe with higher field strengths and longer read-out trajectories. Updating the shim settings between acquisition of different slices allows for optimizing the shims to smaller subvolumes, but puts high requirements on the timing characteristics of the shim switching. Here the settling dynamics of the higher order shims were measured using a 3rd order dynamic field camera. Long-living (seconds) eddy currents were found, which had a significant effect on image quality. Based on measured k-space trajectories, it was possible to reconstruct phantom images acquired during eddy current settling.