Here are some subjects who had multiple anatomical datasets acquired.
Use these to create surfaces with cortical reconstruction software such 
as FreeSurfer, SureFit/Caret, Brain Voyager.

Be sure to process the volumes "prior" to cortical reconstruction.
E.g.,

1) Each dataset should be intensity normalized (ie, nonuniformity correction/
bias field correction) with programs AFNI 3dUniformize or MNI nu_correct

2) Do a motion correction/ volume registration on the volumes (AFNI 3dvolreg)

3) Average the datasets together (AFNI 3dMean)