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Updated: May 28, 2026
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Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Amygdala microstructural changes in subjective cognitive decline: A diffusion kurtosis and neurite orientation
Ryn Flaherty1,2, Yu Veronica Sui1, Arjun V Masurkar3,4,5
1Department of Radiology, New York University Grossman School of Medicine, Bernard and Irene Schwartz Center for Biomedical Imaging, New York, NY, USA.
Journal of Alzheimer'S Disease : JAD
|May 27, 2026
Summary
Subjective cognitive decline (SCD) shows altered amygdala microstructure, particularly with lower kurtosis fractional anisotropy (KFA) and higher free water fraction (FWF). These changes may indicate neuroinflammation and are linked to aging in individuals with SCD.
Area of Science:
- Neuroimaging
- Alzheimer's Disease Research
- Cognitive Neuroscience
Background:
- Subjective cognitive decline (SCD) signifies elevated Alzheimer's disease risk.
- Amygdala volume changes are noted in SCD, but underlying microstructural alterations are less understood.
- Investigating amygdala microstructure is crucial for early detection and understanding disease progression.
Purpose of the Study:
- To assess amygdala microstructural differences between SCD and control participants using advanced diffusion MRI techniques.
- To explore correlations between amygdala microstructure, volume, age, memory, anxiety, and depression in SCD.
- To identify potential imaging biomarkers for early detection of neurodegeneration in SCD.
Main Methods:
- Diffusion tensor imaging (DTI), diffusion kurtosis imaging (DKI), and neurite orientation dispersion and density imaging (NODDI) were applied to diffusion MRI data.
- 123 SCD participants and 194 age-matched controls (age > 55) were analyzed.
- Statistical analyses included group comparisons and correlation analyses for diffusion metrics, clinical data, and cognitive performance.
Main Results:
- SCD participants exhibited significantly lower fractional anisotropy (FA) and kurtosis fractional anisotropy (KFA), and higher free water fraction (FWF) in the left amygdala compared to controls.
- Reduced KFA was observed in the right amygdala of SCD participants.
- No significant group differences in amygdala volume were found. Bilateral KFA negatively correlated with FWF, suggesting links to neuroinflammation and neurodegeneration.
Conclusions:
- Kurtosis fractional anisotropy (KFA) effectively differentiates amygdala microstructure between SCD and control groups.
- Amygdala microstructural changes, including KFA alterations, may reflect neuroinflammation and heightened sensitivity to aging in SCD.
- These findings highlight KFA as a potential sensitive biomarker for early Alzheimer's disease detection.
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