Fig. 3.
Boxplots of the FDG ratio (partial volume corrected [PVCY]) in the AD-signature meta-ROI among 639 elderly (age ≥70) CN participants, stratified by low (SUVr < 1.5) or high (SUVr ≥ 1.5) PiB retention and APOE ε4 carriers and noncarriers. The only pairwise comparisons that reached a nominal level of significance (uncorrected for multiple comparisons) were low PiB/APOE ε4 noncarrier versus high PiB/APOE ε4 carrier (p < 0.001) and high PiB/APOE ε4 noncarrier versus high PiB/APOE ε4 carrier (p = 0.03). There were 365 low PiB/APOE ε4 noncarriers, 74 low PiB/APOE ε4 carriers, 115 high PiB/APOE ε4 noncarriers, and 85 high PiB/APOE ε4 carriers. Abbreviations: AD, Alzheimer’s disease; APOE, apolipoprotein E; CN, cognitively normal; FDG, 18F-fluorodeoxyglucose; PiB, 11C-Pittsburgh compound B; ROI, region of interest; SUVr, standardized uptake value ratio.