[Magnetic resonance diffusion tractography in the brain--its application and limitation]

Area of Science:

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

Context:

• Magnetic resonance imaging (MRI) techniques like diffusion tensor tractography (DTT) allow in vivo visualization of white matter tracts.
• Virtual dissection of the living human brain is now feasible.
• Software like dTV and VOLUME-ONE has been developed for tracking and visualization.

Purpose:

• To visualize eloquent white matter bundles in relation to brain tumors, infarctions, and other lesions.
• To perform quantitative measurements of specific tracts (tract-specific analysis) for assessing white matter integrity.
• To reveal abnormalities in normal-appearing white matter.

Summary:

• 3D visualization of white matter fibers (e.g., corticospinal tract, optic radiation) aids preoperative evaluation and intraoperative navigation for brain tumors.
• Tract-specific analysis reveals abnormalities in conditions like amyotrophic lateral sclerosis (ALS) and neurocognitive/psychiatric disorders (schizophrenia, Alzheimer's disease).
• Correlation with intraoperative stimulation validates tracking accuracy; analysis of lacunar infarctions near corticospinal tracts predicts motor function recovery.

Impact:

• Diffusion tractography provides a unique tool for visualizing, segmenting, and quantitatively evaluating white matter pathways.
• Development of white matter mapping, including probabilistic maps of the pyramidal tract, enhances understanding of brain organization.
• This technique holds significant future importance in clinical practice and neuroscience research.