Comparison of navigator echo and centroid corrections of image displacement induced by static magnetic field drift on echo planar functional MRI

Image displacement caused by static magnetic field drift may result in seri ous edge artifacts in echo-planar functional magnetic resonance imaging (MR I). We compared navigator echo and centroid methods for correcting the arti facts for phantom and in vivo studies. A motor-stimulation fMRI study was p erformed to demonstrate the possible effects due to the displacement. The n avigator echo method was shown to be the superior technique for the correct ion of image displacement by effectively eliminating edge artifacts, result ing in improved functional maps. (C) 2001 Wiley-Liss, Inc.