Total Intracranial volume estimates

[akhanf]

TIV is a necessity for volumetry so would be nice to include an estimate in the output volume TSV files.

Could use the freesurfer approach which extracts it from a linear transformation to a template space.

[romeopenheiro]

Is it possible to apply the estimated Total Intracranial Volume, aka ICV, to the anat output of Hippunfold? I do not have the dicoms for the dataset (I only have the structural MRI : T1-MPRAGE) that are generally required to implement this. I am hoping to correct for the variance in brain volume among participants.

[akhanf]

Yes it will be fine to just apply the eTIV (e.g. from freesurfer) to anything in the native or cropped-native space (e.g. space-T1w or space-cropT1w) in the anat folder.

The space-corobl images would already have an affine correction applied to them, unless the --rigid_reg_template flag was used, so for those, would not want to then apply eTIV correction since might over-correct.