A Comparative Study of Diffusion Fiber Reconstruction Models for Pyramidal Tract Branches

Area of Science:

• Neuroimaging
• Diffusion MRI
• Tractography

Background:

• Comparative studies on diffusion models for pyramidal tract (PT) quantification are lacking.
• Accurate tractography is crucial for understanding motor pathway integrity.

Purpose of the Study:

• To evaluate and compare the quantification accuracy of four mainstream diffusion models for PT and PT branches.
• To identify the optimal diffusion model for PT and PT branch analysis.

Main Methods:

• Utilized the Human Connectome Project (HCP) dataset with 50 healthy volunteers.
• Applied Diffusion Tensor Imaging (DTI), Diffusion Spectral Imaging (DSI), Generalized Q-space sampling Imaging (GQI), and Q-ball Imaging (QBI).
• Differentiated true and false PT fibers based on anatomical information and statistical analysis.

Main Results:

• GQI and QBI models yielded significantly higher numbers, percentages, and densities of true PT fibers compared to DTI and DSI (p < 0.0005).
• False fiber counts were significantly lower with GQI and QBI (p < 0.0005).
• PT trunk and limb branches showed more true fibers with GQI and QBI than DTI and DSI (p < 0.0005).

Conclusions:

• GQI and QBI are superior diffusion models for accurate PT and PT branch quantification.
• Probabilistic maps of PT branches reveal unique spatial distributions, aiding motor pathway research.
• Publicly shared maps facilitate precise studies on motor pathway plasticity and damage.