New eddy current compensation technique in NMR imaging using field feedback

Abstract

A new eddy current compensation method is presented, using the well-known feedback theory. When the pulsatile current is applied to the gradient coil to generate gradient field, undesirable gradient field term is induced by the eddy current. This eddy current comes from the mutual interaction between gradient coil and surrounding conductors. In this thesis, a feedback method is proposed to compensate the undesired field. The compensation result from the proposed field feedback method is several times better than that obtained by the pre-compensating filter method using the eddy current compensator. This resultant can be applied to the compensator design by the parameter extraction. This proposed method has been implemented to the KAIS 2.0T whole body MRI System.