title: Multisite fMRI reproducibility of a motor task using identical MR systems.
abstract: OBJECTIVE
  To estimate between-scanner functional MRI (fMRI) reproducibility in a multisite study.
  
  
  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).
  
  
  CONCLUSIONS
  These results support the feasibility of multisite studies using identical scanner systems.
authors: Brain Image Analysis Unit, Institute of Psychiatry, King's College London, UK. s.costafreda@iop.kcl.ac.uk
authors: Sergi G
authors: SG
authors: Costafreda
authors: Michael J
authors: MJ
authors: Brammer
authors: Ricardo Z N
authors: RZ
authors: Vêncio
authors: Maria L
authors: ML
authors: Mourão
authors: Luiz A P
authors: LA
authors: Portela
authors: Claudio Campi
authors: CC
authors: de Castro
authors: Vincent P
authors: VP
authors: Giampietro
authors: Edson
authors: E
authors: Amaro
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D009044:Motor Cortex / Q000473:pathology*; D015588:Observer Variation; D015203:Reproducibility of Results