P4‐195: Can We Harmonize PIB and Florbetapir Datasets?

plasma free fraction of 1060.5% and 3862% of parent fraction remaining at 10 min. Blood flow was decreased compared to controls (on average over the target regions -1264% and -1166% for aMCI andADD respectively) andwas significant in posterior cingulate cortex (p<0.0001) (Figures 1-2). R1 correlated significantly (p<0.0001) with [15O]-H2O SUVr in all cortical regions (Pearson’s r ranged from 0.63 to 0.88 for the parietal and temporal cortex respectively). Mean VT was significantly increased compared to controls in relevant cortical regions for aMCI (on average +34613%) and for ADD (+38614%) (Figure 4). Compared to VT, SUVr overestimated differences between aMCI and HC in all regions (on average +863%) while underestimating differences between ADD and aMCI (-1061%). Conclusions: Quantitative PET imaging using absolute VT increases discriminating power between the different groups compared to static SUVr (Figure 5), the latter being sensitive to heterogeneous perfusion changes. 1 van Berckel, BN et al. J. Nucl. Med. 54, 1570-1576 (2013).