Assessment of the interaction Tau x Amyloid effect on FDG PET SUVR. The SVD-based tau scores show large areas of association with the reduction of glucose metabolism after adjusting for the effect of β-amyloid. In contrast, β-amyloid did not produce areas of statistical significance after adjusting for tau. Likewise, the interaction between β-amyloid and tau did not show regions surviving the multiple comparisons thresholding.
Panel A in the figure shows that the SVD-based tau scores still produced extended areas of association with the reduction of glucose metabolism after adjusting for the effect of distributed β-amyloid.
In contrast, Panel B shows that the main effect of β-amyloid did not produce areas of statistical significance on FDG SUVR after adjusting for the effect of distributed tau.
Similarly, as shown in Panel C, the interaction term between β-amyloid and tau did not show regions surviving the multiple comparisons thresholding, although the tau-related reduction of glucose metabolism in areas such as lateral inferior temporal cortex, precuneus, and parietal cortex seems to be relatively associated with an increase of β-amyloid.
Notice that, although not statistically significant, the increase in β-amyloid seems to be associated with a positive relationship between FDG and tau in large areas of the cortex, particularly within the frontal cortex.