Multisite fMRI reproducibility of a motor task using identical MR systems

Purpose To estimate between‐scanner functional MRI (fMRI) reproducibility in a multisite study. Materials and Methods A total of five identical 1.5T MR systems were used to repeatedly scan five subjects while performing a finger tapping task. A two‐way (scanners, subjects) random effects analysis of variance (ANOVA) was used to estimate between‐scanner and between‐subject variability on two outcome variables: task‐related mean blood oxygenation level dependent (BOLD) signal change and volume of activation within a motor region‐of‐interest (ROI). Results Between‐scanner variability of fMRI data accounted for a small proportion of the total variation in the BOLD signal change (8.34%, P = 0.114) and volume of activation (5.46%, P = 0.203). Between‐subject variation accounted for more than half of the total variation for both measurements (57.17% and 54.46%, respectively, P < 0.01). Conclusion These results support the feasibility of multisite studies using identical scanner systems. J. Magn. Reson. Imaging 2007;26:1122–1126. © 2007 Wiley‐Liss, Inc.