Analysis of the eddy-current induced artifacts and the temporal compensation in nuclear magnetic resonance imaging

摘要

Reduction of eddy currents by a temporal compensation of the input current waveform to the gradient coil is studied with an analytic solution. The technique is the inverse filtering of the eddy-current affected field response, which is calculated from the diffusion equation. The limitation of the temporal compensation due to the spatially variant eddy currents is also investigated for whole-body diagnostic imaging systems and small-bore nuclear magnetic resonance (NMR) microscopy systems. Within a limited imaging volume of less than 60% of the gradient coil diameter, most of eddy-current problems can be solved by the technique.