Axel Hartwig1, Magnus Mrtensson2, Stefan Skare1
1Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; 2EMEA Research and Collaboration, Applied Science Laboratory, GE Healthcare, Stockholm, Sweden
Patient head motion is one of the leading sources of artifacts in brain MRI. Motion in the 'nodding direction' is particular difficult to restrain and will, in 2D axial and coronal scans, cause spin-history effects through the plane which cannot be addressed retrospectively. In this work, we propose a 2D fat-only (FatNav) navigator image for prospective correction of head nodding motion. FatNav is advantageous over water-based navigators as it leaves the brain water magnetization unaffected. We have shown that the motion estimates using the FatNav images reflects the true 'nodding motion' of a moving subject.