Jennifer Nussbaum1, Maria Engel1, and Klaas Paul Pruessmann1
1Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
1Institute for Biomedical Engineering, ETH Zurich and University of Zurich, Zurich, Switzerland
When performing concurrent field
monitoring with NMR field probes and a head coil, the field measurement can be
corrupted by eddy currents on the head coil that are induced by the MR gradients.
In this work, we provide a one-time calibration solution to correct for this
issue.
EPI reconstructed
with concurrent field monitoring (without SENSE and without B0 correction).
Left: reconstructed using corrected probe signal for the trajectory calculation,
middle: reconstructed without probe signal correction, right: difference image.
The ghosts disappear when the concurrently monitored probe phases, used to
calculate the trajectory, are corrected.
Phase correction of an
x-gradient frequency swept pulse (20 mT/m). In the zoom it can be seen that the
corrected signal (red) coincides with the signal that is measured in absence of
the head coil (blue).