Exploration of scanning effects in multi-site structural MRI studies

J Neurosci Methods. 2014 Jun 15;230:37-50. doi: 10.1016/j.jneumeth.2014.04.023. Epub 2014 Apr 28.


Background: Pooling of multi-site MRI data is often necessary when a large cohort is desired. However, different scanning platforms can introduce systematic differences which confound true effects of interest. One may reduce multi-site bias by calibrating pivotal scanning parameters, or include them as covariates to improve the data integrity.

New method: In the present study we use a source-based morphometry (SBM) model to explore scanning effects in multi-site sMRI studies and develop a data-driven correction. Specifically, independent components are extracted from the data and investigated for associations with scanning parameters to assess the influence. The identified scanning-related components can be eliminated from the original data for correction.

Results: A small set of SBM components captured most of the variance associated with the scanning differences. In a dataset of 1460 healthy subjects, pronounced and independent scanning effects were observed in brainstem and thalamus, associated with magnetic field strength-inversion time and RF-receiving coil. A second study with 110 schizophrenia patients and 124 healthy controls demonstrated that scanning effects can be effectively corrected with the SBM approach.

Comparison with existing method(s): Both SBM and GLM correction appeared to effectively eliminate the scanning effects. Meanwhile, the SBM-corrected data yielded a more significant patient versus control group difference and less questionable findings.

Conclusions: It is important to calibrate scanning settings and completely examine individual parameters for the control of confounding effects in multi-site sMRI studies. Both GLM and SBM correction can reduce scanning effects, though SBM's data-driven nature provides additional flexibility and is better able to handle collinear effects.

Keywords: ICA; Multi-site; Multivariate; SBM; sMRI.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Brain / anatomy & histology*
  • Brain / pathology
  • Brain Stem / anatomy & histology
  • Brain Stem / pathology
  • Calibration
  • Female
  • Humans
  • Image Processing, Computer-Assisted / methods*
  • Magnetic Resonance Imaging / methods*
  • Male
  • Middle Aged
  • Multicenter Studies as Topic / methods*
  • Multivariate Analysis
  • Neuroimaging / methods
  • Schizophrenia / pathology
  • Thalamus / anatomy & histology
  • Thalamus / pathology
  • Young Adult