Question Posted 11/05/16:
Dear ADNI experts,
I have two questions looking at the DXSUM_PDXCONV_ADNIALL.csv and ROSTER.csv:
(1) I'm trying to figure out the subject IDs of the subjects who converted or reverted (NC-to-MCI, MCI-to-AD or vice versa). Unfortunately it seems like not all the subjects in the DX... table also appear in the ROSTER table (e.g. I couldn't find the subject with ID=1088, RID=241,site=107 in the roster table (there is no subject with ID=1088 at this table). Can you please explain where this data is kept and how to find it?
(2) For the subjects who have either converted or reverted, how are they classified in the dataset? For instance, if I am searching for MRI image data and I'm checking the MCI checkbox in the Search Query, do the result contain subjects who have converted to AD as well? Are the scans of these subjects classified as AD or MCI (or is it classified as MCI before conversion and AD after?)

Looking forward to your responce!

Thank you!

Response posted 11/08/16 by Danielle:
RID is the unique subject identifier used to link records between data files, not ID (RID 241 is in the ROSTER table).

In the IDA, where you can download images, the diagnosis at the screening visit is what is used in the search query, I believe.