How to use SUIT for VBM

Voxel-based morphometry (VBM) involves a voxel-wise comparison of the local concentration of gray matter between two groups of subjects. This technique is exceptionally useful in the analysis of degenerated or damaged cerebella, one can derive a quantifiable measure of the degeneration/damage when comparing a healthy and unhealthy group. VBM is based on the segmentation map that indicates the probability of a voxel being gray matter.

Latter can also be submitted over the SPM job manager:

job.subj.affineTr={['Affine_<name>' subjName '_seg1.mat']}; % Affine transformation

job.subj.flowfield={['u_a_<name>' subjName '_seg1.nii']}; % This is the flowfield

job.subj.resample{1}={['<name>' subjName '_seg1.nii']}; % Gray matter image.

job.subj(s).mask={['c_struct<name>' subjName '_pcereb_corr.nii']}; % Mask

job.jactransf=1; % Imporant for VBM


Doing VBM with SUIT has two main advantages: First, the overlap of cerebellar structures is improved, and second, by masking the image before reslicing it into the atlas space, no supra-tentorial gray matter can bias the results.

More information on VBM can be found here.

Gray Matter

For normalization of gray matter probability map, the option preserve should be set to 1