Just in case you didn't find the modified Schaefer-Yeo atlas,
https://afni.nimh.nih.gov/pub/dist/atlases/SchaeferYeo/

The irregularity of those regions in both surface and volumes led to those modifications we worked on with Thomas Yeo's group.

For DTI analysis, you may want to move the atlas ROI into your native space via the std141*niml.dset files. Those are on a "standard mesh" that can be shared across subjects' surface datasets on the same standard mesh. The way I recommend then is to project those std141*niml.dset files into the volume using @surf_to_vol_spackle. You can dilate the cortical ribbon mask to expand into the white matter or follow Paul's procedure for expanding into the white matter with 3dROImaker, or @ROI_modal_grow.