Vector concomitant field mapping by phase contrast imaging

We show that concomitant field-induced phase in phase-contrast imaging allows measurement of the transverse (x,y) components of the magnetic field generated by a gradient coil. Combined with conventional B0 mapping which gives the z-component, the method permits experimental determination of the full three-dimensional vector magnetic field of a gradient coil. We demonstrate the method on a high-performance head gradient (MAGNUS) system and discuss its application to concomitant-field artifact correction based on one-time calibration.