Retrospective registration-based MRI motion correction with interleaved radial trajectories

Despite reduction in imaging times through improved hardware and rapid acquisition schemes, motion artifacts can compromise image quality in magnetic resonance imaging (MRI). This is especially true for 3D imaging, where scan durations are prolonged and the assumptions of most state-of-the-art 2D rigid body motion compensation techniques break down. This paper introduces a novel motion correction technique that is capable of restoring image quality in motion corrupted 2D/3D radial acquisitions. First, the available set of projections is subdivided into motion-free subsets of data using a novel center of mass based motion detection approach. For acquisitions with multiple receiver coils, both rotational and translational motion are detected. Next, the motion parameters are estimated on a sub-pixel level by co-registration of the data subsets. This approach does not require any additional navigators or external motion estimation schemes. The capabilities and limitations of the method are described and demonstrated on an application in cranial imaging.