Tract-specific analysis of white matter pathways in healthy subjects: a pilot study using diffusion tensor MRI

Area of Science:

• Neuroimaging
• Diffusion Tensor Imaging (DTI)
• White Matter Tractography

Background:

• Limited data exists on normal diffusion properties of white matter (WM) fibers.
• Establishing normative data is crucial for identifying pathological changes in neurological diseases.
• This study focuses on key WM tracts: uncinate fasciculus (UF), posterior cingulum (PC), fornix, and corticospinal tract (CST).

Purpose of the Study:

• To create a database of normal diffusion tensor metrics for specific cerebral WM fibers in healthy adults.
• To investigate the influence of age and laterality on diffusion tensor metrics of these WM tracts.
• To utilize tract-specific analysis via diffusion tensor tractography (DTT).

Main Methods:

• Diffusion tensor tractography (DTT) was performed on 100 healthy subjects.
• Mean diffusivity (MD) and fractional anisotropy (FA) were measured for selected WM tracts.
• Statistical analyses included Pearson correlation for age effects and paired t testing for hemispheric asymmetry.

Main Results:

• Normative FA and MD values were established for UF, PC, fornix, and CST.
• Significant correlations were found between age and MD (right UF, bilateral fornices) and age and FA (bilateral fornices).
• Observed hemispheric asymmetries included FA in UF (right > left) and MD in CST (left > right).

Conclusions:

• The study provides a normative dataset for diffusion parameters of four critical WM tracts.
• This dataset serves as a reference for identifying and characterizing tract-specific changes in disease states.
• Age and laterality are significant factors influencing diffusion metrics in these white matter tracts.