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Diffusion Tensor Magnetic Resonance Imaging in the Analysis of Neurodegenerative Diseases
Published on: July 28, 2013
Quantitative analysis along the pyramidal tract by length-normalized parameterization based on diffusion tensor
Fuchun Lin1, Chunshui Yu, Tianzi Jiang
1National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
Neuroimage
|August 22, 2006
Summary
A new method normalizes white matter tract length for consistent analysis across individuals. This revealed diffusion changes in the pyramidal tract (PYT) of relapsing neuromyelitis optica (RNMO) patients, suggesting potential secondary degeneration.
Area of Science:
- Neuroimaging
- Neuroscience
- Medical Physics
Background:
- Relapsing neuromyelitis optica (RNMO) can cause white matter damage.
- Assessing subtle white matter changes, particularly in the pyramidal tract (PYT), is challenging.
- Existing methods lack precise anatomical correspondence for tract analysis across subjects.
Purpose of the Study:
- To introduce a novel length-normalized parameterization method for white matter tracts.
- To establish anatomical correspondence of the pyramidal tract (PYT) across subjects.
- To investigate diffusion abnormalities in the PYT of RNMO patients without visible brain lesions.
Main Methods:
- Reconstructed the PYT between specific anatomical landmarks (cerebral peduncle and lateral ventricle).
- Parameterized the PYT by normalizing its length and dividing it into equal segments.
- Calculated diffusion indices (D(av), FA, lambda(1), lambda(23)) for each segment using diffusion tensor tractography.
Main Results:
- Developed distribution maps of diffusion indices along the PYT.
- Found significant differences in D(av), FA, and lambda(23) distribution between RNMO patients and healthy controls.
- Observed the most pronounced differences in the lower segments of the PYT.
Conclusions:
- The length-normalized parameterization method effectively establishes anatomical correspondence for the PYT.
- This method enables quantitative, segment-specific analysis of diffusion indices along white matter tracts.
- The findings suggest secondary degeneration in the PYT of RNMO patients, potentially linked to spinal cord lesions.
