Question Posted 10/17/14:
There appear to be two structural MRI scans per subject in the ADNI-Go. Which do you recommend I use for further analysis, with and without GRAPPA2/SENSE2/Accelerated?
Response posted 10/24/14 by ADNI MRI Core:
Thank you for your question to the ADNI MRI Core.

Yes, there are two sets to 3D T1 scans for each subject. Un-Accelerated and Accelerated.

This is not really an either or question. Both are acceptable for doing analysis on. Un-Accelerated scans have been the gold standard for volumetic studies in the past. So if you are comparing your results to older studies you may chose those. However, that being said, it appears that the field is moving towards only performing accelerated T1 scans for future studies, so you may wish to focus on those for studies moving forward.