SDM   Signed Differential Mapping
Share on Facebook:   Facebook

Signed Differential Mapping
Meta-analytic methods for fMRI, VBM and PET
Software | Tutorial | Manual | Database | Web utilities | The people

New ES-SDM version 2.14 (Oct 2011) available - Click here to expand/contract this box -

Introduction

Signed Differential Mapping is a statistical technique for meta-analyzing studies on differences in brain activity or structure which used neuroimaging techniques such as fMRI, VBM or PET. Meta-analyses using this method have been already published at high quality journals such as Arch Gen Psychiat link link, Am J Psychiatry link, Biol Psychiat link, Schizophrenia Bull link, Br J Psychiat link, Neurobiol Aging link, Neuroimage link, Psychol Med link link, Schizophr Res link, J Clin Psychopharmacol link, J Affect Disorders link, Eur J Neurol link, Eur Psychiat link, Amyotroph Lateral Sc link or Biol Mood Anxiety Disord link.

The method

An introduction of the method can be found in the SDM Reference Manual.

Briefly, some of the features are:

  • Possibility of combining group peak coordinates with parametric images.
  • A criterion in the selection of the coordinates to avoid biases towards liberally thresholded regions.
  • Use of specific gray or white matter templates.
  • Accounting for different sources of spatial error (e.g. coregistration mismatch or the size of the cluster), peaks' effect-size, and signed maps to counteract positive and negative differences.
  • Weights in the calculations: intra-study variance (i.e. studies with large sample sizes and/or lower error contribute more) and other optional weights.
  • Use of the general linear model and inter-study heterogeneity to allow meta-analytical comparisons between groups and use of covariates.
  • Complementary analyses such as exploration of heterogeneity (by means of heterogeneity maps, subgroup analyses and meta-regressions) and jackknife analyses (to assess the replicability of the results).

The software

Please feel free to download the software created by the SDM Project to carry out such meta-analyses.

References

Papers introducing relevant SDM methods:

  • Radua J and Mataix-Cols D. Voxel-wise meta-analysis of grey matter changes in obsessive-compulsive disorder. Br J Psychiatry 2009; 195:393-402. link (SDM method 1/3: original algorithms)
  • Radua J, van den Heuvel OA, Surguladze S and Mataix-Cols D. Meta-analytical comparison of voxel-based morphometry studies in obsessive compulsive disorder vs other anxiety disorders. Arch Gen Psychiatry 2010; 67:701-711. link (SDM method 2/3: comparisons and linear models)
  • Radua J, Mataix-Cols D, Phillips ML, El-Hage W, Kronhaus DM, Cardoner N and Surguladze S. A new meta-analytic method for neuroimaging studies that combines reported peak coordinates and statistical parametric maps. Eur Psychiatry 2011; in Press. link (SDM method 3/3: effect-sizes and variances)
  • Radua J, Via E, Catani M and Mataix-Cols D. Voxel-based meta-analysis of regional white-matter volume differences in autism spectrum disorder versus healthy controls. Psychol Med 2011; 41:1539-1550. link (SDM specific white matter template)

Other studies using SDM:

  • Bora E, Fornito A, Yücel M and Pantelis C. Voxelwise meta-analysis of gray matter abnormalities in bipolar disorder. Biol Psychiatry 2010; 67:1097-1105. link
  • Chen Z and Ma L. Grey matter volume changes over the whole brain in amyotrophic lateral sclerosis: A voxel-wise meta-analysis of voxel based morphometry studies. Amyotroph Lateral Scler 2010; 11:549-554. link
  • Bora E, Fornito A, Radua J, Walterfang M, Seal M, Wood SJ, Yücel M, Velakoulis D and Pantelis C. Neuroanatomical abnormalities in schizophrenia: A multimodal voxelwise meta-analysis and meta-regression analysis. Schizophr Res 2011; 127:46-57. link
  • E Via, J Radua, N Cardoner, F Happe and D Mataix-Cols. Meta-analysis of gray matter abnormalities in autism spectrum disorder. Arch Gen Psychiatry 2011; 68:409-418. link
  • Lai CH. Gray matter deficits in panic disorder: a pilot study of meta-analysis. J Clin Psychopharmacol 2011; 31:287-93.. link
  • Richlan F, Kronbichler M and Wimmer H. Meta-analyzing brain dysfunctions in dyslexic children and adults. Neuroimage 2011; 56:1735-42. link
  • Bora E, Fornito A, Pantelis and Yücel M. Gray matter abnormalities in Major Depressive Disorder: A meta-analysis of voxel based morphometry studies. J Affect Disord 2011; in Press. link
  • Li J, Pan P, Song W, Huang R, Chen K and Shang H. A meta-analysis of diffusion tensor imaging studies in amyotrophic lateral sclerosis. Neurobiol Aging 2011; in Press. link
  • Pan PL, Song W and Shang HF. Voxel-wise meta-analysis of gray matter abnormalities in idiopathic Parkinson's disease. Eur J Neurol 2011; in Press. link
  • Bora E, Fornito A, Yücel M and Pantelis C. The effects of gender on grey matter abnormalities in major psychoses: a comparative voxelwise meta-analysis of schizophrenia and bipolar disorder. Psychol Med 2011; in Press. link
  • Nakao T, Radua J, Rubia K and Mataix-Cols D. Gray matter volume abnormalities in ADHD: Voxel-based meta-analysis exploring the effects of age and stimulant medication. Am J Psychiatry 2011; in Press. link
  • Murphy ML and Frodl T. Meta-analysis of diffusion tensor imaging studies shows altered fractional anisotropy occurring in distinct brain areas in association with depression. Biol Mood Anxiety Disord 2011; 1:3. link
  • Fusar-Poli P, Radua J, McGuire P and Stefan B. Neuroanatomical maps of psychosis onset: Voxel-wise meta-analysis of antipsychotic-naive VBM studies. Schizophrenia Bull 2011; in Press. link


The authors | IoP King's College London | NeuroImageN