Dear ADNI MRI Investigator. Thank you for your question. For ADNI1 yes, the MPRAGE and MPRAGE Repeat are basically the same sequence twice. However sometimes there are more than just two T1s for example if the subject moved in one of the first two scans, the sites would often times would do an additional scan. For ADNIGO and ADNI2 the is an unaccelerated and accelerated T1 sequence, so those are indeed different.