Dan Xu1, R. Scott Hinks1, Bruce
D. Collick
1Applied Science Laboratory, GE
Healthcare, Waukesha, WI, United States
In
echo-planar imaging based functional MRI, non-phase-encoded navigator echoes
are sometimes collected to enable correction of temporal frame dependent
even-odd-echo phase modulation. However, the navigator-based method assumes
that the additional modulation that the center echoes experience is the same
as that predicted by navigator echoes, which is not true when there is
additional modulation building up across echoes. Therefore, the modulation of
the center echoes would not be well corrected, leading to ghost drift. We
propose a method to use scan data itself to more faithfully estimate the
per-temporal-frame modulation than the navigator-based method, which
significantly reduces ghost drift.