AV-45 PET Scan Processing and Analysis

Preprocessing of the AV-45 PET scans and computation of the global AV-45 PET values were done centrally by the ADNI core as described previously [33 (link)]. Briefly, each subject’s florbetapir image was coregistered using SPM8 to that subject’s MRI image that was closest in time to the florbetapir scan. Freesurfer processing was carried out to skull-strip, segment and delineate cortical and subcortical regions in all MRI scans [34 (link),35 (link)]. Volume-weighted florbetapir means from a cortical summary region were extracted. A single binary cortical summary region composed of all the subregions was created to calculate the mean uptake across each region. We used the summary data of global and regional results (frontal, parietal and cingulate regions that have been most frequently associated with EF performance [36 (link),37 (link),38 (link),39 (link)]). SUVr determination was based on the whole cerebellum reference region. Details regarding regions of interest forming the subregions frontal, parietal and cingulate have been described previously [33 (link)].