Real-time correction by optical tracking with integrated geometric distortion correction for reducing motion artifacts in functional MRI.

Magn Reson Med. 2012 May 14;

Authors: Rotenberg D, Chiew M, Ranieri S, Tam F, Chopra R, Graham SJ

Abstract
Head motion artifacts are a major problem in functional MRI that limit its use in neuroscience research and clinical settings. Real-time scan-plane correction by optical tracking has been shown to correct slice misalignment and nonlinear spin-history artifacts; however, residual artifacts due to dynamic magnetic field nonuniformity may remain in the data. A recently developed correction technique, Phase Labeling for Additional Coordinate Encoding, can correct for absolute geometric distortion using only the complex image data from two echo planar images with slightly shifted k-space trajectories. An approach is presented that integrates Phase Labeling for Additional Coordinate Encoding into a real-time scan-plane update system by optical tracking, applied to a tissue-equivalent phantom undergoing complex motion and an functional MRI finger tapping experiment with overt head motion to induce dynamic field nonuniformity. Experiments suggest that such integrated volume-by-volume corrections are very effective at artifact suppression, with potential to expand functional MRI applications. Magn Reson Med, 2012. © 2012 Wiley Periodicals, Inc.

PMID: 22585554 [PubMed - as supplied by publisher]