Question Posted 04/11/18:
Hello, I found the T1-weighted images acquired with GE and FSPGR serials weren't performed gradwrap. So can I merge the images with SPGR serials which were performed gradwarp and N3 corrected and the images with FSPGR serials which were performed N3 corrected only.
Response posted 04/14/18 by ADNI MRI Core:
Thank you for your question to the ADNI MRI Core.

Yes, that is how the data was intended to work. Wherever the MRI system could preform gradwarp it was enabled and this no post processing gradwarp was applied.