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Abstract #0571

A Method to Remove Nyquist Ghosts from Echo Planar Images (EPI) Using UNFOLD

W Scott Hoge1, Huan Tan2, Robert A. Kraft2

1Radiology, Brigham and Women's Hospital, Boston, MA, USA; 2Wake Forest University School of Medicine, Winston-Salem, NC, USA


Nyquist ghosts are a persistent artifact in echo planar imaging (EPI), and occur when data sampled along positive and negative read-out gradients is inconsistent. Previous methods to correct these effects include double-sampled EPI, which doubles the echo train length leading to greater magnetic susceptibility artifacts, and echo interleave strategies that carry a cost of reduced temporal resolution. Here, we present an approach using the slightly modified trajectory common to interleave strategies, but utilizing UNFOLD in place of interleaving to combine the data. This has the advantage of greatly reducing visible Nyquist ghosts while maintaining 90% of the original temporal sampling bandwidth.