Hector
Sanchez1, Michael Poole1, Stuart Crozier1
1Research Group/Affiliation: EMI,
School of Information Technology & electrical Engineering, Brisbane, QLD,
Australia
MRI
requires rapidly switched magnetic field gradients. This time-dependent
magnetic fields induce eddy currents in nearby conducting structures. These
currents generate detrimental transient magnetic fields in the region of
interest (ROI) and hence current compensation (CC) is required to minimize
the consequential image distortion. In order to apply successfully CC
techniques, it is required that the primary and the secondary magnetic fields
possess a similar spatial form in the ROI. We investigated by simulation, the
effect of re-shaping a highly conducting passive shield surrounding a
gradient coil (and the gradient coil surface) over the matching field for
optimal current compensation.