Abstract: A method for correcting for main magnetic field (B0) inhomogeneity in a Magnetic Resonance Imaging (MRI) scanner is disclosed. The method includes applying a first and a second three-dimensional volumetric navigator after an acquisition of a volume in a scanning sequence and before the next volume is acquired. From a resultant pair of navigator images, a magnetic field map is obtained by complex division of the pair of navigator images, and the field map is used to determine parameters to adjust the MRI scanner to compensate for B0 inhomogeneity. The navigators may excite only a portion of an entire object to be imaged, so that adjustment of the MR scanner can be done slice-by-slice or slab-by-slab. Motion correction can also be implemented by comparing the first navigator to a stored reference image and updating for motion before acquisition of the next volume in the scanning sequence.

Abstract: A method for correcting for main magnetic field (B0) inhomogeneity in a Magnetic Resonance Imaging (MRI) scanner is disclosed. The method includes applying a first and a second three-dimensional volumetric navigator after an acquisition of a volume in a scanning sequence and before the next volume is acquired. From a resultant pair of navigator images, a magnetic field map is obtained by complex division of the pair of navigator images, and the field map is used to determine parameters to adjust the MRI scanner to compensate for B0 inhomogeneity. The navigators may excite only a portion of an entire object to be imaged, so that adjustment of the MR scanner can be done slice-by-slice or slab-by-slab. Motion correction can also be implemented by comparing the first navigator to a stored reference image and updating for motion before acquisition of the next volume in the scanning sequence.