Comparison of Fat Navigators and Optical Camera Based Retrospective Motion Correction

Motivation: A comparison between efficacies of navigators and optical camera in retrospective motion correction (MC) on brain MR images remains largely unknown. Goal(s): Our goal was to compare two motion tracking techniques (fat navigators [FatNav] and markerless optical camera [MoCAP]) and their performance in MC. Approach: Twenty-one healthy subjects were imaged by T2-weighted turbo-spin-echo sequence with their head movements monitored simultaneously by both techniques. Performance was evaluated by image sharpness calculated at lateral ventricle/white matter boundary. Results: Compared to MoCAP, FatNav had lower motion scores and less fluctuations at small motion. Images after FatNav-based MC showed greater sharpness than MoCAP. Impact: The better performance of FatNav-based MC despite low temporal resolution suggest that FatNav can be integrated with MoCAP to achieve robust image quality in the presence of both abrupt and slow head motions.