-dti_in  INPREF :basename of DTI volumes output by, e.g., 3dDWItoDT.
                     NB- following volumes are *required* to be present:
                     INPREF_FA, INPREF_MD, INPREF_L1,
                     INPREF_V1, INPREF_V2, INPREF_V3,
                     and (now) INPREF_RD (**now output by 3dTrackID**).
                     Additionally, the program will search for all other
                     scalar (=single brik) files with name INPREF* and will
                     load these in as additional quantities for WM-ROI
                     stats; this could be useful if, for example, you have
                     PD or anatomical measures and want mean/stdev values
                     in the WM-ROIs (to turn this feature off, see below,
                     'dti_search_NO'); all the INPREF* files must be in same
                     DWI space.
                     Sidenote: including/omitting a '_' at the end of INPREF
                     makes no difference in the hunt for files.

-dti_in /Users/dti-afni_*.nii.gz

-dti_in /Users/dti-afni