Real-time motion correction in two-dimensional multislice imaging with through-plane navigator.

PURPOSE: To develop a new real-time strategy to detect and correct for full three-dimensional rigid-body motion in two-dimensional multislice magnetic resonance imaging scans.
METHODS: Two through-plane navigator echoes collected on each imaging slice are used to reconstruct two orthogonal through-plane navigator projection images both perpendicular to the imaged slices, within each repetition time. Rotation/translation within each through-plane navigator image plane is detected using a regional image correlation measure that is robust against unaccounted orthogonal rotation and noise. An additional orbital navigator is used to detect rotation within the imaging plane and to reject intrarepetition time motion in real time.
RESULTS: The efficacy of the proposed method was demonstrated with in vivo brain studies.
CONCLUSION: The proposed real-time three-dimensional motion correction method does not introduce any additional three-dimensional radiofrequency excitation and does not require any additional hardware.