Related Experiment Video
Updated: Dec 9, 2025
Hybrid PET/MRI Imaging of Alzheimer's Disease Based on 18F-AV-1451
Published on: April 18, 2025
Quantitative susceptibility mapping in β-Amyloid PET-stratified patients with dementia and healthy controls - A
Solveig Tiepolt1, Michael Rullmann2, Thies H Jochimsen1
1Department of Nuclear Medicine, University of Leipzig, Liebigstr. 18, 04103 Leipzig, Germany.
Purpose:
Post-mortem and in-vivo MRI data suggest an accumulation of iron in the brain of Alzheimer's disease (AD) patients. The majority of studies in clinically diagnosed AD patients found an increase of iron-sensitive MRI signals in the putamen. As the clinical diagnosis shows only a moderate sensitivity, Aβ-PET was used to further stratify patients with the clinical diagnosis of AD. Aim of this exploratory study was to examine whether Aβ-positive (AD) and Aβ-negative (non-AD) patients differ in their regional magnetic susceptibility compared to healthy controls (HCs) and whether regional susceptibility values correlate with mini mental state examination (MMSE) scores or global Aβ-load.
Methods:
We retrospectively analyzed [11C]PiB PET/MRI data of 11 HCs, 16 AD and 10 non-AD patients. We used quantitative susceptibility mapping (QSM) as iron-sensitive MRI signal measured at the 3 T PET/MR scanner. Global cerebral Aβ-load was determined by composite [11C]PiB SUV ratios.
Results:
Compared to HCs, AD patients showed higher QSM values in putamen (0.049 ± 0.033 vs. 0.002 ± 0.031; p = 0.006), while non-AD patients showed lower QSM values in caudate nucleus (0.003 ± 0.027 vs. 0.051 ± 0.039; p = 0.006). There was a trend towards a significant correlation between putaminal QSM and MMSE values (ρ=-0.340, p = 0.053). In AD patients, global Aβ-load and putaminal QSM values were significantly correlated (ρ=-0.574, p = 0.020).
Conclusions:
These data indicate that AD and non-AD patients may show different cerebral iron pathologies which might be detectable by QSM MRI, and might be linked to neurodegeneration. Overall, the data encourage further investigations in well-defined patient cohorts to clarify the value of QSM/magnetic susceptibility in the course of neurodegenerative diseases and its potential as diagnostic biomarker.
Insights
Alzheimer's disease (AD) patients show distinct brain iron levels detectable by quantitative susceptibility mapping (QSM) MRI. These iron differences may correlate with neurodegeneration and could serve as a diagnostic biomarker.
Area of Science:
- Neuroimaging
- Biomarkers
- Neurodegenerative Diseases
Background:
- Accumulation of iron in the brain is observed in Alzheimer's disease (AD).
- Previous studies indicate increased iron-sensitive MRI signals in the putamen of AD patients.
- Clinical diagnosis of AD has moderate sensitivity; Aβ-PET aids in patient stratification.
Purpose of the Study:
- To investigate differences in regional magnetic susceptibility between Aβ-positive (AD), Aβ-negative (non-AD) patients, and healthy controls (HCs).
- To explore correlations between magnetic susceptibility, Mini Mental State Examination (MMSE) scores, and global Aβ-load.
Main Methods:
- Retrospective analysis of [11C]PiB PET/MRI data from 11 HCs, 16 AD, and 10 non-AD patients.
- Quantitative susceptibility mapping (QSM) used to measure iron-sensitive MRI signals at 3T.
- Global cerebral Aβ-load determined by composite [11C]PiB SUV ratios.
Main Results:
- AD patients exhibited higher putaminal QSM values compared to HCs (p=0.006).
- Non-AD patients showed lower caudate nucleus QSM values than HCs (p=0.006).
- A significant correlation was found between global Aβ-load and putaminal QSM in AD patients (ρ=-0.574, p=0.020).
Conclusions:
- Quantitative susceptibility mapping (QSM) may detect distinct cerebral iron pathologies in AD and non-AD patients.
- Observed iron differences are potentially linked to neurodegeneration.
- Further research in well-defined cohorts is encouraged to validate QSM as a diagnostic biomarker for neurodegenerative diseases.
