WHOLE-BRAIN FUNCTIONAL MAPPING WITH ISOTROPIC MR-IMAGING

PURPOSE: To assess the reliability and sensitivity of gradient-echo, i sotropic multisection echo-planar magnetic resonance (MR) imaging for within-subject whole-brain mapping. MATERIALS AND METHODS: Eight right -handed healthy volunteers underwent gradient-echo, echo-planar MR ima ging while they performed a motor task on three occasions over 23 mont hs. Ninety-six whole-brain volumes were acquired in 8 minutes 48 secon ds. A rigorous statistical threshold for determining activation was se t at P < .05 and was Bonferroni corrected for approximately 15,000 cor tical voxels. RESULTS: In all subjects, reproducible activation was de monstrated in multiple cortical areas and in the cerebellum specific t o the motor system. Of the activated voxels, 75%-78% were confined to the motor areas during all sessions. No statistically significant diff erence was found in the proportion of activated voxels in any motor re gion (relative to the total number of activated voxels in the whole br ain) across the three sessions. The centers of mass of the activated a reas were within 2.5 resolution elements of the image across the three sessions. CONCLUSION: Isotropic multisection echo-planar MR imaging h as the potential for noninvasive, reliable within-subject mapping of w hole-brain functional anatomy.