[Freesurfer] acquisition in 1 session vs 2 sessions

Dear experts,

We are designing a study including a long MR protocol:

1) Localizer 2) Cal 3) T1-FSPGR 4) FLAIR 3D 5) DTI 1 6) DTI 2 7) fMRI

Due to patients characteristics we were thinking on splitting the acquisition in two different sessions (session 1: sequences 1, 2, 3, 4; session 2: sequences 1, 2, 5, 6, 7).

Do you think we should do the same for the healthy controls or we can scan them in just one single session? I wonder how system session-related artifacts could differentially affect the two kinds of protocol (spitted vs. single). I also wonder how FreeSurfer processing can be affected by this issues.

Thanks a lot.

Daniel Ferreira