Department of Radiology, Konkuk University Medical Center, Seoul, Republic of Korea.
Laboratory for Imaging Science and Technology, Department of Electrical and Computer Engineering, Seoul National University, Seoul, Republic of Korea.
Korean J Radiol. 2023 Nov;24(11):1131-1141. doi: 10.3348/kjr.2023.0490.
Cortical iron deposition has recently been shown to occur in Alzheimer's disease (AD). In this study, we aimed to evaluate how cortical gray matter iron, measured using quantitative susceptibility mapping (QSM), differs in the clinical cognitive impairment spectrum.
This retrospective study evaluated 73 participants (mean age ± standard deviation, 66.7 ± 7.6 years; 52 females and 21 males) with normal cognition (NC), 158 patients with mild cognitive impairment (MCI), and 48 patients with AD dementia. The participants underwent brain magnetic resonance imaging using a three-dimensional multi-dynamic multi-echo sequence on a 3-T scanner. We employed a deep neural network (QSMnet+) and used automatic segmentation software based on FreeSurfer v6.0 to extract anatomical labels and volumes of interest in the cortex. We used analysis of covariance to investigate the differences in susceptibility among the clinical diagnostic groups in each brain region. Multivariable linear regression analysis was performed to study the association between susceptibility values and cognitive scores including the Mini-Mental State Examination (MMSE).
Among the three groups, the frontal ( < 0.001), temporal ( = 0.004), parietal ( = 0.001), occipital ( < 0.001), and cingulate cortices ( < 0.001) showed a higher mean susceptibility in patients with MCI and AD than in NC subjects. In the combined MCI and AD group, the mean susceptibility in the cingulate cortex (β = -216.21, = 0.019) and insular cortex (β = -276.65, = 0.001) were significant independent predictors of MMSE scores after correcting for age, sex, education, regional volume, and APOE4 carrier status.
Iron deposition in the cortex, as measured by QSMnet+, was higher in patients with AD and MCI than in NC participants. Iron deposition in the cingulate and insular cortices may be an early imaging marker of cognitive impairment related neurodegeneration.
最近的研究表明，阿尔茨海默病（AD）患者大脑皮质存在铁沉积。本研究旨在评估使用定量磁化率映射（QSM）测量的皮质灰质铁在临床认知障碍谱中的差异。
本回顾性研究纳入了 73 名认知正常（NC）者（平均年龄 ± 标准差，66.7 ± 7.6 岁；52 名女性和 21 名男性）、158 名轻度认知障碍（MCI）患者和 48 名 AD 痴呆患者。所有参与者均在 3T 扫描仪上接受了三维多动态多回波序列的脑磁共振成像。我们使用深度神经网络（QSMnet+）和基于 FreeSurfer v6.0 的自动分割软件提取皮质的解剖标签和感兴趣区体积。我们采用协方差分析来研究每个脑区不同临床诊断组之间的磁化率差异。多变量线性回归分析用于研究认知评分（包括简易精神状态检查（MMSE））与磁化率值之间的关系。
在这三组中，MCI 和 AD 患者的额（ < 0.001）、颞（ = 0.004）、顶（ = 0.001）、枕（ < 0.001）和扣带回皮质（ < 0.001）的平均磁化率高于 NC 受试者。在 MCI 和 AD 合并组中，校正年龄、性别、教育程度、局部容积和 APOE4 携带者状态后，扣带回皮质（β = -216.21， = 0.019）和岛叶皮质（β = -276.65， = 0.001）的平均磁化率是 MMSE 评分的独立预测因素。
使用 QSMnet+测量的皮质铁沉积在 AD 和 MCI 患者中高于 NC 参与者。扣带和岛叶皮质的铁沉积可能是与认知障碍相关的神经退行性变的早期影像学标志物。
