HAI Book 2025 - Flipbook - Page 138
Unschuld, Paul
16
Distinct patterns of Iron distribution in the entorhinal cortexhippocampus system for characterization of mild cognitive impairment
Sonja M. Kagerer1,2,4, Laetitia Vionnet5, Jiri M. G. van Bergen1, Rafael Meyer1,2, Anton Gietl1,2,
Klaas Prüssmann5, Christoph Hock1, Paul G. Unschuld3,4
1
Institute for Regenerative Medicine (IREM), University of Zurich, Zurich, CH
Department of Geriatric Psychiatry, Psychiatric University Hospital Zurich, Zurich, CH
3
Geriatric Psychiatry Service, University Hospitals of Geneva (HUG), Geneva, CH
4
Department of Psychiatry, University of Geneva (UniGE), Geneva, CH
5
Institute for Biomedical Engineering, University of Zurich and ETH Zurich, Zurich, CH
2
Introduction: The entorhinal cortex-hippocampus system plays a central role in memory processing and is
affected early in aging related neurodegenerative brain disorders such as Alzheimer9s disease (AD). Cognitive
dysfunction in AD is a result of progressive neuropathological alterations which include non-specific copathologies such as accumulation of non-heme iron in vulnerable brain regions. The current study used an
experimental high-resolution 7 Tesla magnetic resonance imaging (MRI) setup to characterize iron distribution in
hippocampal subfields and entorhinal cortex (EC).
Methods: 40 old-aged participants with full neuropsychological work-up (mean age [SD] 69.2 [7.42] years; 12 MCI,
28 cognitively healthy controls (HC)) underwent 7 Tesla MRI using turbo spin echo scanning for structural imaging
and quantitative susceptibility mapping (QSM) for non-heme iron content. Image quality of high resolution ultrahigh field MRI data was assured by real-time field control. Gray matter segmentation was performed with
FreeSurfer Version 6.0 software. Intraclass correlation coefficients (ICCs) were calculated to characterize
consistency of regional hippocampal subfield and EC susceptibility measures.
Results: ICCs for the mean regional susceptibilities were 0.61 for all subjects (n=40), 0.58 for the HC group (n=28),
and 0.69 for the MCI group (n=12). Two-sample Kolmogorov-Smirnov test showed a significant difference of the
ICCs between the HC and MCI group (k=0.625, pf0.05).
Discussion: Our data suggest distinctive patterns of non-heme brain iron distribution in the EC-hippocampus
system that characterize MCI. Future studies are needed to confirm whether altered brain iron distribution may
serve as potential biomarker of non-specific AD co-pathology.
Keywords: Hippocampus, entorhinbal cortex, QSM, iron, MRI
HAI2025 - 138
