Motion Compensation with Floating Navigator and GRAPPA Operators

Introduction Recent developments in partially parallel imaging (PPI) techniques provide new opportunities for motion artifact reduction [1-2]. One PPI technique that exhibits great potentials in many motion detection and correction scenarios is the GRAPPA operator [3], as the GRAPPA kernels can be flexibly positioned for k-space interpolation and extrapolation in any direction. This work proposes a new motion detection and correction method for applications using multiple channel coil arrays. The method uses the image-space correlation of floating navigators for detection of translational, rotational and non-consistent (e.g. through-plane and non-rigid body) motion. GRAPPA operators are then used to correct the k-space data, and hence suppressing motion artifacts.