Imaging Alzheimer's genetic risk using diffusion MRI: A systematic review.
Judith R Harrison1, Sanchita Bhatia2, Zhao Xuan Tan2
1Cardiff University Brain Research Imaging Centre (CUBRIC), Maindy Road, Cardiff CF24 4HQ, UK.
Neuroimage. Clinical
|August 8, 2020
Summary
Alzheimer's risk genes are linked to white matter changes in the brain, impacting areas like the temporal and frontal lobes. Diffusion MRI studies show these changes are clearest in individuals with diagnosed Alzheimer's disease.
Area of Science:
- Neuroimaging
- Neuroscience
- Genetics
Background:
- Diffusion magnetic resonance imaging (dMRI) assesses water molecule diffusion in tissues.
- dMRI is crucial for studying white matter microstructure alterations in Alzheimer's Disease (AD).
Purpose of the Study:
- To systematically review research on how Alzheimer's risk genes affect white matter microstructure.
- To analyze diffusion pre-processing and analysis methods used in these studies.
Main Methods:
- Systematic review of 37 studies.
- Analysis of diffusion tensor (DT) imaging metrics like fractional anisotropy and mean diffusivity.
- Inclusion of studies using advanced dMRI techniques beyond DT MRI.
Main Results:
- Increased AD genetic risk correlates with reduced white matter anisotropy and increased diffusivity.
- Affected brain regions include temporal/frontal lobes, cingulum, and corpus callosum.
- Structural abnormalities are most pronounced in individuals with established Alzheimer's Disease.
Conclusions:
- dMRI reveals widespread white matter changes associated with AD genetic risk.
- Current dMRI methods lack disease-specific pathology identification.
- Advanced dMRI techniques may aid in early AD diagnosis and staging.
