Kagerer Sonja M, Vionnet Laetitia, van Bergen Jiri M G, Meyer Rafael, Gietl Anton F, Pruessmann Klaas P, Hock Christoph, Unschuld Paul G
Institute for Regenerative Medicine (IREM), University of Zurich, Schlieren, Switzerland.
Geriatric Psychiatry and Psychotherapy, University Hospital of Psychiatry Zurich (PUK), Zurich, Switzerland.
Front Aging Neurosci. 2025 Jul 2;17:1598859. doi: 10.3389/fnagi.2025.1598859. eCollection 2025.
The entorhinal cortex (EC)-hippocampus system is critical for memory and affected early in Alzheimer's disease (AD). Cognitive dysfunction in AD is linked to neuropathological changes, including non-heme iron accumulation in vulnerable brain regions. This study characterized iron distribution in the EC-hippocampus system using ultra-high field (UHF) magnetic resonance imaging (MRI) at 7 Tesla (T) in aging and mild cognitive impairment (MCI), an AD at-risk state.
40 participants (mean age [SD] 69.2 [7.42] years; 12 mild cognitive impairment (MCI), 28 cognitively healthy controls (HC)) underwent UHF MRI at 7 T with turbo spin echo and quantitative susceptibility mapping (QSM). Gray matter segmentation was performed using FreeSurfer software. Intraclass correlation coefficients (ICCs) were calculated for hippocampal and EC measures.
ICCs for mean susceptibilities were 0.61 overall, 0.58 for HC, and 0.69 for MCI, with significant group differences between HC and MCI (Kolmogorov-Smirnov test, = 0.625, ≤ 0.05).
Our findings suggest a higher coherence of non-heme iron distribution in MCI. An increasingly uniform distribution of iron in MCI could reflect a clinical continuum ranging from healthy aging to pathologic brain change and cognitive disorder. This highlights the potential of non-heme iron as a biomarker for early AD co-pathology.
内嗅皮层（EC）-海马体系统对记忆至关重要，且在阿尔茨海默病（AD）早期就会受到影响。AD中的认知功能障碍与神经病理变化有关，包括易损脑区的非血红素铁积累。本研究使用7特斯拉（T）的超高场（UHF）磁共振成像（MRI）对衰老和轻度认知障碍（MCI，一种AD风险状态）患者的EC-海马体系统中的铁分布进行了表征。
40名参与者（平均年龄[标准差]69.2[7.42]岁；12名轻度认知障碍（MCI）患者，28名认知健康对照者（HC））接受了7T的UHF MRI检查，采用快速自旋回波和定量磁化率映射（QSM）技术。使用FreeSurfer软件进行灰质分割。计算海马体和EC测量指标的组内相关系数（ICC）。
平均磁化率的ICC总体为0.61，HC为0.58，MCI为0.69，HC和MCI之间存在显著的组间差异（柯尔莫哥洛夫-斯米尔诺夫检验，=0.625，≤0.05）。
我们的研究结果表明MCI中非血红素铁分布的一致性更高。MCI中铁分布越来越均匀可能反映了从健康衰老到病理性脑变化和认知障碍的临床连续过程。这突出了非血红素铁作为早期AD共同病理学生物标志物的潜力。
