title: Motion correction using an enhanced floating navigator and GRAPPA operations.
abstract: A method for motion correction in multicoil imaging applications, involving both data collection and reconstruction, is presented. The floating navigator method, which acquires a readout line off center in the phase-encoding direction, is expanded to detect translation/rotation and inconsistent motion. This is done by comparing floating navigator data with a reference k-space region surrounding the floating navigator line, using a correlation measure. The technique of generalized autocalibrating partially parallel acquisition is further developed to correct for a fully sampled, motion-corrupted dataset. The flexibility of generalized autocalibrating partially parallel acquisition kernels is exploited by extrapolating readout lines to fill in missing "pie slices" of k-space caused by rotational motion and regenerating full k-space data from multiple interleaved datasets, facilitating subsequent rigid-body motion correction or proper weighting of inconsistent data (e.g., with through-plane and nonrigid motion). Phantom and in vivo imaging experiments with turbo spin-echo sequence demonstrate the correction of severe motion artifacts.
authors.affiliation: Invivo Corporation, Philips Healthcare, Gainesville, Florida 32608, USA. wei.lin2@philips.com
authors.forename: Wei
authors.initials: W
authors.lastname: Lin
authors.forename: Feng
authors.initials: F
authors.lastname: Huang
authors.forename: Peter
authors.initials: P
authors.lastname: Börnert
authors.forename: Yu
authors.initials: Y
authors.lastname: Li
authors.forename: Arne
authors.initials: A
authors.lastname: Reykowski
mesh_terms: D000465:Algorithms; D016477:Artifacts; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D019047:Phantoms, Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity