In a method and apparatus for motion-corrected magnetic resonance (MR) imaging, MR data are acquired in a diagnostic scan in respective portions, and between each portion of acquired diagnostic data, a navigator scan is implemented wherein navigator data are acquired simultaneously in multiple slices in a navigator sub-volume that is less than the volume of the acquisition volume. A reference scan is acquired before beginning the diagnostic scan, and the navigator data in the sub-volumes are acquired between the acquisition of the portions of the MR data in the diagnostic scan. Between each acquisition portion, a motion-correction algorithm is executed, wherein the navigator data of the sub-volume is compared only to corresponding image data in the reference scan, and, if necessary, a motion-correction instruction is generated that is used for the acquisition of the next diagnostic data portion.