Abstract
INTRODUCTION: Alzheimer's disease (AD) is a neurodegenerative condition characterised by amyloid plaque accumulation and neurofibrillary tangles. Early detection is essential for effective intervention, but current diagnostic methods that enable early diagnosis in clinical practice rely on invasive or costly biomarker scanning. This study aimed to explore the utility of 7T MRI in assessing hippocampal subfield volumes and their correlation with cerebrospinal fluid (CSF) biomarkers in prodromal AD. METHODS: Fifty-six participants, including AD patients and healthy controls, underwent 7T MRI scanning. Automated segmentation delineated hippocampal subfield volumes, with subsequent normalisation to whole brain volume. RESULTS: Significant differences in hippocampal and subfield volumes were observed in prodromal AD patients, even when they did not exhibit high MTA scores on 3T MRI or show any whole brain volume loss. Additionally, the volume of the entorhinal cortex (ERC) correlated significantly with CSF amyloid-β levels, suggesting ERC's potential as a proxy CSF amyloid-ß measurement. Conversely, no significant associations were found between CSF 181-Phosphorylated-tau or total tau levels and any hippocampal subfield volumes. DISCUSSION: These findings show the potential use of 7T MRI, particularly in ERC assessment, as a biomarker for early AD identification. Further validation studies are warranted to confirm these results and elucidate the relationship of ERC volume with CSF biomarkers.