The correlation between striatal and cortical binding ratio of ¹¹C-PiB-PET in amyloid-uptake-positive patients

In subjects with amyloid deposition, striatal accumulation of ¹¹C-Pittsburgh compound B (PiB) demonstrated by positron emission tomography (PET) is related to the stage of Alzheimer's disease (AD). In this study, we investigated the correlation between striatal and cortical non-displaceable binding potential (BP_ND).

Seventy-three subjects who complained of cognitive disturbance underwent dynamic PiB-PET studies and showed positive PiB accumulation were retrospectively selected. These subjects included 34 AD, 26 mild cognitive impairment, 2 frontotemporal lobar degeneration, 2 Parkinson's disease, 5 dementia with Lewy bodies, and 4 undefined diagnosis patients. Individual BP_ND images were produced from the dynamic data of the PiB-PET study, and voxel-based analyses were performed to estimate the correlations between striatal and other regional cortical BP_ND measures.

There were highly significant correlations between striatal and prefrontal BP_ND, with the highest correlation being demonstrated in left Brodmann area 11. We found that almost all of the high cortical BP_ND values correlated with striatal BP_ND values, with the exception of the occipital cortex with low correlation.

Our study demonstrated positive correlations in amyloid deposits between the striatum and other cortical areas with functional and anatomical links. The amyloid distribution in the brain is not random, but spreads following the functional and anatomical connections.