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Updated: May 29, 2026
09:33
Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
T1-weighted/T2-weighted ratio reflects microstructural changes in Alzheimer's disease.
N Reijner1,2, M Riscado Ramos3, E Jacobs3
1Department of Anatomy and Neurosciences, Section Clinical Neuroanatomy and Biobanking, Amsterdam UMC, De Boelelaan 1108, Amsterdam, 1081 HZ, The Netherlands. n.reijner@amsterdamumc.nl.
Alzheimer'S Research & Therapy
|May 28, 2026
Summary
The T1-weighted/T2-weighted ratio (T1w/T2w-ratio) is not solely a myelin marker in Alzheimer's disease (AD). It reflects broader microstructural changes, including amyloid-beta, tau pathology, and neuro-axonal damage, making it a valuable tool for tracking AD progression.
Area of Science:
- Neuroimaging
- Neuropathology
- Biomarker Discovery
Background:
- The T1-weighted/T2-weighted ratio (T1w/T2w-ratio) is a neuroimaging technique used to assess myelin content.
- Its utility may extend beyond myelin to reflect broader microstructural integrity changes.
- This study investigates the T1w/T2w-ratio's ability to detect microstructural changes in Alzheimer's disease (AD).
Purpose of the Study:
- To evaluate the T1w/T2w-ratio's capability in detecting microstructural alterations in the context of Alzheimer's disease.
- To determine if the T1w/T2w-ratio is specific to myelin or indicative of other pathological changes in AD.
Main Methods:
- Postmortem and antemortem MRI scans from control and AD brain donors were analyzed.
- T1w/T2w-ratio images were generated and parcellated using the Brainnetome atlas.
- Immunohistochemistry was performed to quantify amyloid-beta, tau, neuro-axonal damage, myelin, microglia, and iron.
Main Results:
- The T1w/T2w-ratio was significantly lower in AD brains compared to controls.
- A strong correlation was observed between antemortem and postmortem T1w/T2w-ratios.
- In AD, T1w/T2w-ratio correlated with myelin, microglia, amyloid-beta, phosphorylated tau, and neuro-axonal damage, but not iron.
Conclusions:
- The T1w/T2w-ratio is associated with myelin density in controls but reflects broader microstructural integrity in AD.
- It is not a myelin-specific marker in AD but correlates with key AD pathologies.
- The T1w/T2w-ratio can serve as a valuable neuroimaging tool for tracking longitudinal microstructural changes in AD when interpreted with other biomarkers.
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