A novel Approach in MRI Signal Processing for Unveiling the Intricacies of Brain Axonal Organization

Abstract

Abstract 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 opts for diffusion-sensitizing gradient directions (dSGDs, representing the directions along which signals are generated) aligned with reduced signal intensities. By treating these chosen directions as maximum diffusivity directions, we generate uniformly distributed gradient directions (GDs) around them, which are subsequently employed in the reconstruction process. This approach overcomes drawbacks present in existing methods, such as the uniform gradient directions (UGDs) approach, which exhibits gradient direction redundancy, and the adaptive gradient direction (AGDs) approach, requiring solving the linear system twice per voxel. Our 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.