Hello all,
I am doing pre-processing for resting-state fMRI volumes, but I have encountered an error and am unsure of how to correct it:
I have previously determined the nonlinear warping transformations from my subjects' anatomical (T1) space to the 2mm MNI template using ANTs. At the end of my pre-processing pipeline, I am trying to transform my subjects' functional volumes (206 TRs of 2sec) into this MNI space by 1) transforming the functional volumes into subject T1 space using mri_vol2vol, and 2) applying the nonlinear warp (from ANTs) to the volumes in subject-T1 space to ultimately have my subjects' functional data in MNI space.
However, I am getting an error while running mri_vol2vol, where it "cannot allocate region." I gather from looking around online that this is a memory issue, but I am not sure how to fix it. Thoughts? It is crucial that I be able to translate my functional data into common MNI space before performing second-level analyses...
I do not encounter this issue when performing this transformation on functional connectivity maps (where I take an ROI defined in MNI space, transform it into T1, and then subject-EPI space, calculate the FC with the rest of the brain, and then invert the process by transforming back into T1, and finally MNI space). How can I get this to work with a larger file?
Thank you in advance for your help,
Ben Mooneyham