Hi,

I'm trying to perform seed-based functional connectivity analysis, but I noticed that the grid size of the processed epi data from running afni_proc.py are different from those of my seed mask. The mask is in MNI space with dimensions of 91x109x91 2mm voxel size, but the processed epi that results from proc.py is 96x114x96 2mm.

By my understanding, the grid size of the final epi dataset is adopted from the anatomical dataset through coregistration because the anatomical dataset is inputted through the -master option. And, the grid size of the anatomical dataset uses that of the MNI152_2009_SSW template from SSWarper, which I perform before running proc.py. Is that right? Therefore, is there a MNI template for SSWarper which would have a grid size of approximately 182x218x182 1mm, which when the resolution is changed to a voxel size of 2mm for epi data would yield the desired dimensions of 91x109x91 2mm?

Or, is this a simple matter of using 3drefit to adjust the dimensions of the final epi and anat datasets?

Thanks,
Daniel