Hi Tyler,

by mapping the DTI to the anatomical space, you will automatically account for partial voluming in the DTI space. The partial volume correction in mri_segstats is for correcting within the 1mm3 anatomical voxel, which seemed excessive given the large DTI voxel sizes (but maybe it's not). It is better not to use aparc+aseg to extract surface-based measures because it is effectively just counting the number of 1mm3 voxels. The surface-based method is better because the surface has higher resolution. Why do you need stats after transformation?

doug

Tyler Blazey wrote:

Hi,

I have two questions about using mri_segstats. First, I notice that on the individual dti tutorial, you don't use the --pvol option to correct for partial voluming. Is there a reason for this? Second, would there be any disadvantage to using mri_segstats with aparc+aseg.mgz to get volume/ thickness measurements? I know from the ReconAllDevTable that the standard method is to use mris_anatomical_stats, but I need to get the stats after transforming the aparc+aseg image, so that is not an option. Thanks for any help.

• Tyler

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