The discovery of preclinical Alzheimer's disease (preAD) provides a wide time window for the early intervention of AD. The coupling relationships between glucose and oxygen metabolisms from hybrid PET/MRI can provide complementary information on the brain's physiological state for preAD. In this study, we purpose to explore the change of coupling relationship among 27 normal controls (NCs), 20 preADs, and 15 cognitive impairments (CIs). For each subject, we calculated the Spearman partial correlation between the fractional amplitude of low-frequency fluctuations (fALFF) and the regional homogeneity (ReHo) from functional image (fMRI), and the standard uptake value ratio (SUVR) from [18F] fluorodeoxyglucose positron emission tomography (¹⁸F-FDG PET), in the whole-brain and default mode network (DMN) as a novel potential biomarker. The diagnostic performance of this biomarker was evaluated by the receiver operating characteristic analysis. Significant Spearman correlations between the FDG SUVR and the fALFF/ReHo were found in 98% of subjects. For the DMN-based biomarker, there was a significant decreasing trend for the preAD and CI groups compared to the NC group, whereas no significant difference in preAD based on whole-brain. The correlation ρ value for the FDG SUVR/ReHo showed the highest area under curve of the preAD classification (0.787). The results imply the coupling relationship changed during the preAD stage in the DMN area.

中文翻译：

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葡萄糖和氧代谢之间的耦合关系以区分临床前阿尔茨海默病和正常个体

临床前阿尔茨海默病（preAD）的发现为AD的早期干预提供了广阔的时间窗口。来自混合 PET/MRI 的葡萄糖和氧代谢之间的耦合关系可以为 preAD 提供有关大脑生理状态的补充信息。在本研究中，我们旨在探讨 27 名正常对照 (NC)、20 名 preAD 和 15 名认知障碍 (CI) 之间耦合关系的变化。对于每个受试者，我们计算了低频波动的分数幅度 (fALFF) 与功能图像 (fMRI) 的区域均匀性 (ReHo) 之间的 Spearman 偏相关性，以及来自 [18F] 氟脱氧葡萄糖的标准摄取值比 (SUVR)正电子发射断层扫描（¹⁸F-FDG PET），在全脑和默认模式网络（DMN）中作为一种新的潜在生物标志物。该生物标志物的诊断性能通过接受者操作特征分析进行评估。在 98% 的受试者中发现了 FDG SUVR 和 fALFF/ReHo 之间的显着 Spearman 相关性。对于基于 DMN 的生物标志物，与 NC 组相比，preAD 和 CI 组有显着下降趋势，而基于全脑的 preAD 没有显着差异。FDG SUVR/ReHo 的相关 ρ 值显示 preAD 分类曲线下面积最高 (0.787)。结果表明，在 DMN 区域的 preAD 阶段，耦合关系发生了变化。