2. Segmentation

Segmentation of the individual session T1-weighted images is performed according to the following steps:

1. The group template priors are warped to the single subject template (SST) space
2. A mask is created in SST space by finding all voxels that are non-zero in the priors warped to the SST space
3. Atropos is run on the SST to get tissue class posteriors than can be used as priors for the individual sessions (priors weight = .25)
4. Posteriors from Atropos on the SST are warped to the session space
5. A mask is created in session space by finding all voxels that are non-zero in the priors (posteriors from Atropos on SST) warped to the session space
6. Atropos is run on the session T1w image with the posteriors from Atropos on the SST, warped to session space, serving as the priors (priors weight = .5; more confident in these because within person)