Question

Question Posted 05/11/17:
I suppose to work with 11C-PiB PET scans. Therefore, I have two questions regarding the image collections search queries.
1- When I select the groups, I found that MCI and LMCI groups exist only in ADNI 1. Since I am interested to work MCI group of the disease, I want to know what is the difference between those two groups, please?
2- When I choose 11C-PiB in the "Radiopharmaceutical" option while leaving "Radioisotope" without checking neither C-11 nor F-18 I got results that differ from checking each of them separately. What is the description of the resulting scans when selecting: F-18 in "Radioisotope" and 11C-PiB in "Radiopharmaceutical"? are they 11C-PiB?
Response posted 05/16/17 by Danielle:
In ADNI-1, there were 3 groups of individuals (NL, MCI, AD). ADNI-GO added an "early MCI" group (EMCI), which consists of individuals with an MCI diagnosis but not as extreme of a memory impairment. The MCI of ADNI-1 were deemed "late MCI" or LMCI. In ADNI-2, NL, EMCI, LMCI, and AD participants were recruited.

If you are interested in PiB scans, those were only done on a subset of individuals in ADNI-1. I just looked at the Image Data Archive, and if I select 11C-PIB as the Radiopharmaceutical without selecting a Radioisotope, those scans all appear to have been collected in ADNI1 based on the dates, so were PiB scans. I'm not sure why a few of them have a radioisotope of F-18, but a radiopharmaceutical of 11C-PIB. I checked a couple of those scans against the data file with the regional SUVR of the PIB scans and found an entry in the PIB data file which would further suggest they are PIB scans.