title: Prospective acquisition correction for head motion with image-based tracking for real-time fMRI.
abstract: In functional magnetic resonance imaging (fMRI) head motion can corrupt the signal changes induced by brain activation. This paper describes a novel technique called Prospective Acquisition CorrEction (PACE) for reducing motion-induced effects on magnetization history. Full three-dimensional rigid body estimation of head movement is obtained by image-based motion detection to a high level of accuracy. Adjustment of slice position and orientation, as well as regridding of residual volume to volume motion, is performed in real-time during data acquisition. Phantom experiments demonstrate a high level of consistency (translation < 40 microm; rotation < 0.05 degrees ) for detected motion parameters. In vivo experiments were carried out and they showed a significant decrease of variance between successively acquired datasets compared to retrospective correction algorithms.
authors.affiliation: Siemens Medical Systems, MR Applications Development, Erlangen, Germany. stefan.thesen@med.siemens.de
authors.forename: S
authors.initials: S
authors.lastname: Thesen
authors.forename: O
authors.initials: O
authors.lastname: Heid
authors.forename: E
authors.initials: E
authors.lastname: Mueller
authors.forename: L R
authors.initials: LR
authors.lastname: Schad
mesh_terms: D000465:Algorithms; D016477:Artifacts; D003199:Computer Systems; D019416:Head Movements / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008962:Models, Theoretical; D009038:Motion; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012815:Signal Processing, Computer-Assisted