Patent ID: 7112964
Filing Date: 2006-09-26
Classification: G01R

Abstract:
1. A method for measuring and correcting for eddy currents in a magnetic resonance imaging system, said method comprising: turning at least a portion of a pre-emphasis eddy current correction system of the magnetic resonance imaging system off; running a pulse sequence using bipolar gradient pulses to acquire a phase-difference image and a phase response of a static phantom that fills a majority of a field of view (FOV) of the magnetic resonance imaging system, wherein said running also comprises running the pulse sequence to provide a first delay Te; fitting the phase difference image to a two-dimensional second order polynomial; changing the pulse sequence to provide a second delay different than the first delay Te; iterating said running a pulse sequence and fitting the phase difference image and phase response a plurality of times with a plurality of different delays to determine coefficients of the second order polynomial and a time constant of the phase response; correcting the pre-emphasis eddy current correction system in accordance with the time constant of the phase response; determining an amplitude of correction to reduce the determined coefficients; and storing the determined amplitude corrections in the pre-emphasis eddy current correction system.