Patent ID: 6313630
Filing Date: 2001-11-06
Classification: G01R

Abstract:
In an MRI system which performs pulse sequences to acquire NMR data from a region of interest, a gradient system which comprises:a pulse generator for producing logical gradient waveforms during the performance of a pulse sequence;a rotation processor connected to receive the logical gradient waveforms and multiplying them by a rotation matrix to produce physical gradient waveforms;a distribution processor connected to receive the physical gradient waveforms and produce corresponding primary gradient waveforms and corresponding supplemental gradient waveforms;a first Eddy current compensation processor connected to receive the primary gradient waveforms and produce compensated primary gradient waveforms;first gradient amplifiers connected to receive the compensated primary gradient waveforms and produce corresponding currents in a first set of gradient coils;a second Eddy current compensation processor connected to receive the supplemental gradient waveforms and produce compensated supplemental gradient waveforms; anda second gradient amplifier connected to receive the compensated supplemental gradient waveforms and produce corresponding currents in a second set of gradient coils,wherein the compensated primary and supplemental gradient waveforms received respectively by the first and second gradient amplifiers can differ from one another and can occur at a variety of different levels corresponding to a variety of different modes of operation of the MRI system.