High-resolution segmented EPI in a motor task fMRI study

A high-resolution gradient echo, multi-slice segmented echo planar imaging method was used for functional MRI (fMRI) using a motor task at 1.5 Tesla. Functional images with an in-plane resolution of 1 mm and slice thickness o f 4 mm were obtained with good white-gray matter contrast. The multi-shot a pproach, combined with a short total readout period of 82 ms, limits blurri ng effects for short T-2* tissues (such as gray matter), assuring truly hig h-resolution images. In all subjects, motor functions were clearly depicted in the contralateral central sulcus over several slices and sometimes acti vation was detected in the supplementary motor area and/or ipsilateral cent ral sulcus. The average signal change of 11 +/- 3% was much higher than in standard low-resolution fMRI EPI experiments, as a result of larger relativ e blood fractions. (C) 2000 Elsevier Science Inc. All rights reserved.