A novel approach in MRI signal processing for unveiling the intricacies of brain axonal organization

This article introduces an innovative methodology to unveil the intricacies of white matter fiber pathways in the brain using diffusion MRI. Relying on the rationale that traditional methods observe a significant decrease in signal intensity values in the direction of higher diffusivity, our novel approach strategically selects for diffusion-sensitizing gradient directions (dSGDs, representing the directions along which signals are generated) aligned with reduced signal intensities. By treating these selected directions as maximum diffusivity directions, we generate uniformly distributed gradient directions (GDs) around them, which are subsequently employed in the reconstruction process. This approach addresses the shortcomings of existing methods. It improves upon the uniform gradient directions (UGDs) approach, which suffers from gradient direction redundancy, and the adaptive gradient directions (AGDs) approach, which requires solving the linear system twice per voxel. Proposed method simultaneously addresses both limitations, offering a more efficient and streamlined process. The effectiveness of our proposed methodology is rigorously evaluated through simulations and experiments involving real data, showcasing its superior performance in uncovering the complex white matter fiber pathways in the brain.