SDM reference manual
Introduction
This manual focuses on the software developed for the Signed Differential Mapping (SDM) method, an improved meta-analytic approach for voxel-based neuroimaging studies.
NOTE: It is advisable to first follow the step by step
Tutorial
to achieve an overall idea of the process!
Index
| Introduction | Summary of the method and its main features. | |
| Changes in v3.11 | Changes in the behaviour of SDM software in v3.11 as compared to previous versions. | |
| Preparation | Retrieved neuroimaging data must be included in a folder (see Preparing the folder), and information on samples, groups or variables must be introduced in the SDM table (see Creation of the SDM table). The last step of the preparation is the preprocessing of the studies and their Monte Carlo randomizations (see Preprocessing), preceded by a set of special steps in case of TBSS meta-analyses (see TBSS preprocessing). | |
| Globals analysis | You can conduct a (rather simple) meta-analysis of the global variables, e.g. the global gray matter in a meta-analysis of VBM studies, optionally adjusting for groups or covariates. | |
| Calculations | It is possible to calculate meta-analytic means (see Mean analyses), quartiles (see Descriptive analysis of quartiles), jackknife sensitivity analysis (see Jackknife sensitivity analysis), comparisons between groups including covariates (see Linear model analyses: comparing groups) and meta-regressions (see Linear model analyses: meta-regression). | |
| Results |
Results from previous calculations can be thresholded obtaining
meta-analytic peak coordinates, clusters breakdowns and NIfTI
(Analyze-compatible) images (see
Thresholding the results)
which will be authomatically open in an MRIcron
template (see Settings).
Results of two meta-analyses of studies conducted in different
modalities, e.g. VBM and fMRI, may be combined in a single map
(see Multimodal meta-analyses).
Results can also be extracted extracted from a Talairach label or coordinate
(see Extracting masked values) using a mask
(see Creation of a mask). |
|
| Batch processing | At the moment only one parameter must be specified to run SDM, the brain viewer, useful for authomatically seeing the results with MRIcron after thresholding. | |
| Settings | At the moment only one parameter must be specified to run SDM, the brain viewer, useful for authomatically seeing the results with MRIcron after thresholding. | |
| Running SDM as SPM extension |
SDM can also be run as an SPM (Statistical Parametric Mapping) extension. | |
| How to cite | We have invested a lot of time and effort in creating SDM, please cite it when using it for a meta-analysis. | |
| Troubleshooting | Reported problems and solutions in SDM software. | |
Further reading
Please find more information on the methods in the following articles:
-
Introduction to voxel-based meta-analyses:
Radua J and Mataix-Cols D. Meta-analytic methods for
neuroimaging data explained.
Biol Mood Anxiety Disord 2012; 2:6.
-
SDM method 1/3 (original algorithms):
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.
-
SDM method 2/3 (comparisons and linear models):
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.
-
SDM method 3/3 (effect-sizes and variances):
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 2012; 27:605–611.
-
SDM specific white matter template:
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.
-
SDM specific TBSS preprocessing and template:
Peters BD, Szeszko PR, Radua J, Ikuta T, Gruner P, DeRosse P,
Zhang JP, Giorgio A, Qiu D, Tapert SF, Brauer J, Asato MR, Khong PL,
James AC, Gallego JA and
Malhotra AK. White matter development in adolescence: diffusion tensor imaging and meta-analytic results.
Schizophrenia Bull 2012; 38:1308-1317.
-
Multimodal meta-analyses (theory):
Radua J, Romeo M, Mataix-Cols D and Fusar-Poli P. A general approach for
combining voxel-based meta-analyses conducted in different neuroimaging
modalities.
Curr Med Chem 2013; 20:462-466.
-
Multimodal meta-analyses (example):
Radua J, Borgwardt S, Crescini A, Mataix-Cols D, Meyer-Lindenberg A,
McGuire PK and Fusar-Poli P. Multimodal meta-analysis of structural and functional brain changes
in first episode psychosis and the effects of antipsychotic medication.
Neurosci Biobehav Rev 2012; 36:2325–2333.