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Abstract #0776

A Transverse Gradient Detection Coil for Dynamic Pre-Emphasis

Karl Edler1, David I. Hoult2

1National Research Council Institute for Biodiagnostics, Winnipeg, Manitoba, Canada; 2National Research Council Institute for Biodiagnostics, Canada

It has been shown previously that the effects of eddy currents on a switched z-gradient Gz can be annulled using negative feedback control instead of standard pre-emphasis. Here the method is extended to the more difficult case of transverse gradients. A Gx detection coil was designed with induced voltage proportional to dGx/dt but without response to other field components such as x3, x5, etc. Incorporation of the coil in a feedback loop allowed excellent compensation of eddy currents without a priori knowledge of their effects. Annulment of Bo and higher order transients is amenable to the same approach.