I am using BrainSuite18a. After running svreg, I obtained volumes (cc) of ROIs by clicking “Compute Volumes” (Tools > Mask Tool > ROI Details). However, these numbers do not match wm and gm values in roiwise.stats.txt. For example, in roiwise.stats.txt, I have GM_Volume = 30844.90111 (mm^3) for ROI ID=120 (R. superior frontal gyrus). However, the “Compute Volumes” tool gives 62.2501373 (cc) which is 62250.1373 (mm^3) for ID = 1120 (R. superior frontal gyrus (gm)).
Do IDs 1XXX (gm) and 2XXX (wm) really correspond to GM and WM in XXX region? If so, why their volumes are different from that reported in roiwise.stats.txt? Thank you!
The numbers reported in roiwise.stats.txt use partial tissue fractions in each voxels instead of either counting voxels of gray matter or white matter. Therefore I recommend using that number.
The numbers computed using the label tool computes the number of voxels for a given label. In studies, it might be better to use the former since that approach uses partial tissue fraction in each voxel.