Patent ID: 6836113
Filing Date: 2004-12-28
Classification: G01R

Abstract:
A method for determining a gradient-induced cross-term magnetic field in a magnetic resonance imaging (MRI) system comprising:a. positioning an object in a static magnetic field; b. applying a radio frequency (RF) excitation pulse that spatially selects nuclei of a slice of the object in a slice plane; c. applying an incremented phase-encoding magnetic gradient field along a phase encoding gradient field direction parallel to the slice plane; d. applying a spatially selective RF refocusing pulse along a readout magnetic gradient field direction to select an encoded line in said slice plane; e. sampling nuclear magnetic resonance (NMR) data from nuclei in the selected line by applying a switched readout magnetic gradient to the object, wherein the switched readout gradient generates a cross-term magnetic field with respect to said object; f. transforming the sampled NMR data into an array of data representative of the cross-field effects along the phase encoding gradient field direction, and g. measuring a cross term correction factor for the selected line based on the array of data.