Aberrant susceptibility due to iron level abnormality and brain network disconnections are observed in Alzheimer's disease (AD), with disrupted iron homeostasis hypothesized to be linked to AD pathology and neuronal loss. However, whether associations exist between abnormal quantitative susceptibility mapping (QSM), brain atrophy, and altered brain connectome in AD remains unclear. Based on multi-parametric brain imaging data from 30 AD patients and 26 healthy controls enrolled at the China-Japan Friendship Hospital, we investigated the abnormality of the QSM signal and volumetric measure across 246 brain regions in AD patients. The structural and functional connectomes were constructed based on diffusion MRI tractography and functional connectivity, respectively. The network topology was quantified using graph theory analyses. We identified seven brain regions with both reduced cortical thickness and abnormal QSM ( < 0.05) in AD, including the right superior frontal gyrus, left superior temporal gyrus, right fusiform gyrus, left superior parietal lobule, right superior parietal lobule, left inferior parietal lobule, and left precuneus. Correlations between cortical thickness and network topology computed across patients in the AD group resulted in statistically significant correlations in five of these regions, with higher correlations in functional compared to structural topology. We computed the correlation between network topological metrics, QSM value and cortical thickness across regions at both individual and group-averaged levels, resulting in a measure we call spatial correlations. We found a decrease in the spatial correlation of QSM and the global efficiency of the structural network in AD patients at the individual level. These findings may provide insights into the complex relationships among QSM, brain atrophy, and brain connectome in AD.

中文翻译：

---

阿尔茨海默病中定量敏感性图谱与皮质萎缩和脑连接组的关联：一项多参数研究

在阿尔茨海默病 (AD) 中观察到由于铁水平异常和脑网络断开导致的异常易感性，推测铁稳态破坏与 AD 病理和神经元损失有关。然而，AD 中异常定量磁敏感图 (QSM)、脑萎缩和脑连接组改变之间是否存在关联仍不清楚。基于中日友好医院入组的 30 名 AD 患者和 26 名健康对照的多参数脑成像数据，我们调查了 AD 患者 246 个脑区的 QSM 信号和体积测量异常。结构和功能连接组分别基于扩散 MRI 纤维束成像和功能连接构建。使用图论分析对网络拓扑进行量化。我们确定了AD中皮质厚度减少和QSM异常（<0.05）的七个脑区，包括右额上回、左颞上回、右梭状回、左顶上小叶、右顶上小叶、左顶下小叶，并离开楔前叶。对 AD 组患者的皮质厚度和网络拓扑之间的相关性进行计算，结果发现其中五个区域存在统计学上显着的相关性，与结构拓扑相比，功能性相关性更高。我们在个体和群体平均水平上计算了网络拓扑指标、QSM 值和跨区域皮质厚度之间的相关性，从而得出了我们称之为空间相关性的度量。我们发现 AD 患者个体水平上 QSM 的空间相关性和结构网络的整体效率有所下降。这些发现可能有助于深入了解 AD 中 QSM、脑萎缩和脑连接组之间的复杂关系。