Brain Network Alterations in Alzheimer's Disease Identified by Early-Phase PIB-PET

The aim of this study was to identify the brain networks from early-phase (11)C-PIB (perfusion PIB, pPIB) data and to compare the brain networks of patients with differentiating Alzheimer's disease (AD) with cognitively normal subjects (CN) and of mild cognitively impaired patients (MCI) with CN. Forty participants (14 CN, 12 MCI, and 14 AD) underwent (11)C-PIB and (18)F-FDG PET/CT scans. Parallel independent component analysis (pICA) was used to identify correlated brain networks from the (11)C-pPIB and (18)F-FDG data, and a two-sample t-test was used to evaluate group differences in the corrected brain networks between AD and CN, and between MCI and CN. Our study identified a brain network of perfusion (early-phase (11)C-PIB) that highly correlated with a glucose metabolism ((18)F-FDG) brain network and colocalized with the default mode network (DMN) in an AD-specific neurodegenerative cohort. Particularly, decreased (18)F-FDG uptake correlated with a decreased regional cerebral blood flow in the frontal, parietal, and temporal regions of the DMN. The group comparisons revealed similar spatial patterns of the brain networks derived from the (11)C-pPIB and (18)F-FDG data. Our findings indicate that (11)C-pPIB derived from the early-phase (11)C-PIB could provide complementary information for (18)F-FDG examination in AD.