Signe Johanna Vannesj1, Maximilian Hberlin1,
Lars Kasper1, Christoph Barmet1, Klaas Paul Pruessmann1
1Institute for Biomedical Engineering,
ETH and University Zrich,
MRI
relies on dynamic linear gradients for signal encoding, but the realization
of given gradient time-courses is usually imperfect due to physical
limitations. To characterize the magnetic field response to gradient-channel
inputs the system is here treated as a linear time-invariant system that can
be fully described by its impulse response functions. The field response was
measured up to 3rd order in space with a dynamic field camera, consisting of
16 NMR probes. The measured impulse response functions allowed for accurate
prediction of actual k-space trajectories and also showed predictable
higher-order effects.