RT Journal Article
SR Electronic
T1 <strong>Gray matter structural networks related to <sup>18</sup>F-THK5351 retention in cognitively normal older adults and early Alzheimer</strong><strong>’</strong><strong>s disease patients</strong>
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 604
OP 604
VO 61
IS supplement 1
A1 Yoko Shigemoto
A1 Daichi Sone
A1 Kyoji Okita
A1 Norihide Maikusa
A1 Yukio Kimura
A1 Harumasa Takano
A1 Yuma Yokoi
A1 Masuhiro Sakata
A1 Tadashi Tsukamoto
A1 Koichi Kato
A1 Noriko Sato
A1 Hiroshi Matsuda
YR 2020
UL http://jnm.snmjournals.org/content/61/supplement_1/604.abstract
AB 604Introduction: Alzheimer’s disease (AD) is considered a disconnection syndrome involving local synaptic dysfunction. Although amyloid-β and tau neurofibrillary tangles are hallmarks of AD, few studies have examined the interactive effects of these proteins on structural networks. In this study, we investigated structural network alternations related to tau retention in early AD using a novel method “single-subject gray matter networks” based on cortical similarities within single subjects. Methods: Eighteen amyloid-positive early AD patients and 35 amyloid-negative cognitively normal controls who underwent 3D T1-weighted MRI, amyloid (11C-Pittsburgh Compound B) PET, tau (18F-THK5351) PET were recruited. Single-subject structural networks were extracted from 3D T1-weighted MRI images for each subject. In this method, graphs were defined with nodes representing small cortical regions and edges representing connecting regions which have high statistical similarity within single subjects. Correlation matrices were constructed based on cortical similarities and analyzed using a graph theoretical approach. The obtained global network properties (normalized path length λ, normalized clustering coefficient γ, and small-world value δ) were compared between the groups. We mapped each of local network properties (betweenness centrality, clustering coefficient, and characteristic path length) in the MNI space and compared those properties related to overall cortical tau retention by voxel-level between the groups. Results: The early AD showed more random topology within the range of small-worldness. The local network alternations related to tau retention demonstrated opposite responses between the groups. The cognitively normal controls exhibited a positive correlation between local network alternations and tau retention in the default mode network areas, whereas the early AD demonstrated a negative correlation in those areas. Conclusion: This study indicated that tau retention influences structural connectivity even in cognitively normal individuals. Furthermore, the presence of cortical amyloid might significantly alter tau-related structural connectivity. Single-subject gray matter network analysis may contribute to better understanding of the pathophysiology of AD.