Related Experiment Video
Updated: Aug 6, 2026
Hybrid PET/MRI Imaging of Alzheimer's Disease Based on 18F-AV-1451
Published on: April 18, 2025
Multimodal Imaging of Tau Pathology and Network Connectivity Dynamics Across the Alzheimer's Continuum: A Pilot Study
Sirong Piao1, Jie Wang2, Kun He2
1Department of Radiology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China (S.P.); Department of Radiology, Huashan Hospital, Fudan University, Shanghai 200040, China (S.P., X.L., Y.L., Y.B.); Institute of Functional and Molecular Medical Imaging, Fudan University, Shanghai 200040, China (S.P., N.W., X.L., L.Y., Y.L., Y.B.).
Rationale And Objectives:
Alzheimer's disease (AD) progression involves distinct spatiotemporal changes in functional connectivity (FC) within anterior-temporal (AT) and posterior-medial (PM) networks. This study characterizes FC alterations between medial temporal lobe (MTL) subregions and AT/PM networks across the AD continuum and examines their associations with tau/Aβ pathology and atrophy using second-generation tau-PET.
Materials And Methods:
Eighty-four participants, including 26 cognitively unimpaired Aβ negative(CU Aβ-), 19 cognitively unimpaired Aβ positive (CU Aβ+), 19 mild cognitive impairment Aβ positive(MCI Aβ+), 20 AD Aβ positive(AD Aβ+) underwent 3 T MRI, resting-state fMRI, [¹⁸F]florbetapir (Aβ), and [¹⁸F]MK6240 (tau) PET. MTL subregions were segmented via ASHS-T1, while AT/PM networks were defined using Harvard-Oxford Atlas. Group differences in FC, Aβ/tau standard uptake value ratio(SUVR), and gray matter volume (GMV) were assessed. Network SUVR values, GMV and intra-FC correlation analyses and correlation coefficient matrix plots were calculated.
Results:
Compared to CU Aβ-, CU Aβ+ exhibited increased intra-/inter-network FC (peak in anterior MTL: p < 0.001), while MCI/AD groups showed progressive FC declines. Posterior network FC reduction was pronounced in AD (p < 0.01). Left BA35 connectivity increased in CU Aβ+, whereas AD demonstrated FC reductions in bilateral posterior cingulate/hippocampus. Network-level A/T/N-FC correlations were integrated in CU Aβ+ but modular in AD, with strong tau-GMV anticorrelation.
Conclusion:
Early AD stages feature compensatory AT/anterior MTL hyperconnectivity, transitioning to PM/posterior MTL disintegration as pathology advances. Multimodal biomarker-FC coupling reflects dynamic network reorganization, highlighting MTL-AT/PM connectivity as a biomarker of disease progression.