There have been some modifications to the types of scans acquired throughout the ADNI study. All scans remain available for download by qualified users and are accessible via the Image Data Archive. Listed below are the types of scans collected from each phase of the study. To view a full list of study data, review the data inventory page.
Florbetapir (AV-45) PET and FDG PET imaging is performed on all newly enrolled participants on two separate days (minimum 12 time lapse). Scans are performed within two weeks before or two weeks after the in-clinic assessments at Baseline and at the second annual visit, 24 months after Baseline. Due to funding limitations, EMCI participants carried forward from ADNI GO have a total of two sets of Florbetapir PET and FDG PET imagining across ADNI GO and ADNI 2. The timing of the initial Florbetapir PET and FDG PET scans under ADNI2 are based on the date of the last Florbetapir and FDG PET scan under ADNI GO.
- Every Florbetapir and FDG PET scan is reviewed for protocol compliance by the ADNI PET QC team
- If a correctable problem is identified, the PET QC team contacts the PET technologist directly
- If a problem with the scan is identified and it is not fixable, the PET QC team provides the PET technologist with protocol guidance to apply to future PET scans
In instances of a rescan, participants will be assessed for overall radiation exposure before the repeat scan is scheduled. If it is determined that an additional scan does not put participants at risk of overexposure, study coordinators and site PIs will be contacted and asked to perform the rescan. These repeat scans are performed within two weeks of the original scanning date. If the rescan is performed outside of the allotted window, it is documented in the deviation log.
Scans that fail the PET QC and are deemed unusable due to participant motion or non-compliance are documented with the reason as identified by the participant and the technician on the PET Scan Information Form. In these instances, rescans are only scheduled if the participant’s motion is believed to be correctable and is not a result of chronic illness or deteriorated cognitive ability.