Functional Neuroimaging Laboratory

of the Department of Psychiatry

of the Joan and Sanford I. Weill Medical College

of Cornell University

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This page contains links to software programs and components developed at Functional Neuroimaging Lab, and to other tools we've found useful and collected here for your convenience.


Software

  1. Customized, Optimized, Automated, mostly-SPM-based MATLAB/C/Shell batch programs performing brain imaging data processing and visualization procedures (FNLproc)

  • Automated reconstruction programs that perform various inhomogeneity corrections, slice-timing correction, exaction of physiological noise components from raw functional image series, image maneuver routines such as reslicing, re-orientation, etc.

  • Automated functional and structural brain image preparation routines that transform the reconstructed raw images into specific data format and data structure, ready for further image processing and analysis steps.

  • Automated and optimized image processing procedures, algorithms and programs for both functional and structural brain images, including:

    • Correction for geometric distortion due to magnetic field inhomogeneities based on the B0 field image;

    • Realignment of functional image series to correct for slight head movement between scans based on intracranial voxels;

    • Co-registration of functional images to the corresponding high-resolution anatomical image based on the rigid body transformation parameters of the reference anatomical image (with the same axial slice placement and thickness as the functional imaging) to the latter for each individual subject;

    • Stereotactic normalization to a standardized coordinate space (Montreal MRI Atlas version of Talairach space) based on the intracranial voxels of the high-resolution anatomical image to normalize for individual differences in brain morphology;

    • Spatial smoothing with an isotropic Gaussian kernel.

  1. Customized, Optimized, Automated, mostly-SPM-based MATLAB/C  batch programs performing standard statistical analyses and related procedures (FNLstat)  

  • Automated and optimized routine that define the brain region in functional images for each subject, the temporal global fluctuation is then estimated as the mean intensity within brain region of each volume;

  • Automated GLM routines for building voxel-by-voxel univariate multiple linear regression model at the subject level to determine the extent to which each voxel's BOLD activity correlated with the principal regressor;

  • Automated programs for group-level random-effects analyses including paired t-test, two-sample t-test, single/multiple regression, ANOVA and ANCOVA;

  • Automated and optimized VBM (voxel-based morphometry) analysis program based on structural MRI images;

  • Automated programs for effective connectivity analysis: using adjusted functional BOLD signal from a seed ROI as the principal regressor in a multiple linear regression model for each subject, then at the group level employing a random-effects model to summarize the within-group correlation levels and the between-group differential correlation levels of the other brain regions with the seed ROI;

  • Interactive GUI interface/automated routines performing statistical inference such as two-tailed t-tests with corresponding statistical summary tables, multiple options of brain activation rendering layout and automated printing programs.

  1. Customized, Optimized, Automated fmristat-based MATLAB/C batch programs performing two-stage linear mixed-effects modeling of fMRI data (FNLlme)

  • MATLAB batch programs performing two-stage voxel-wise linear mixed-effects models of fMRI data, which are able to utilize the same set of voxel-wise GLM from prototypical analysis, connectivity analysis to VBM, with reduced biases in effect estimation and more proper modeling of the residuals;

  • Statistical diagnostic programs using partial correlation method to assess the relative contributions of variance components in a multiple regression model;

  • Streamlined programs utilizing high-performance computing clusters to increase computational feasibility of advanced statistical modeling and evaluation procedures at least by a factor of 50-100.

  1. Advanced Statistical Data Analysis Methods Development  

  • Multi-level linear/nonlinear mixed-effects models for nested factors in fMRI data, which address the heteroscedasticity in variance-covariance structure and further reduce the biases in effect estimation (the programs are R-and-C-based);

  • New generation of R/C/Shell based computer programs utilizing high-performance computing clusters to overcome various disadvantages of software tools currently available in neuroimaging field (conventional approaches have primarily relied on various oversimplifications and less-than-optimal methods in favor of low computational cost, recent studies have shown that such a practice can lead to severely biased estimations).

  1. Multivariate Analysis Methods Development  

  • Confirmatory principal component analysis of fMRI data that can be performed within and across groups to detect statistically significant topographic regional patterns of brain activity, and the association between the degree to which each subject expresses such patterns (numerated by loading scores of each subject), and the corresponding clinical and other measures, can then be evaluated through correlation analysis;

  • Independent component analysis of fMRI data based on nonparametric density estimation;

  • Statistical Graphic Model/Structure Equation Modeling/Path Analysis for testing hypotheses concerning the group and condition differences in correlations among the specified brain regions.

  1. User-programmable Database System (FNLBD)

 

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Tools

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Last updated: July 10, 2007.