Understanding tractography in edematous brain regions: challenges and solutions

Fiber tractography is a powerful method for visualizing the complex network of neural connections in the brain, essential for understanding white matter architecture and guiding neurosurgical procedures. However, brain edema presents significant challenges for accurate tractography due to altered diffusion patterns that can obscure critical pathways. The increased isotropic diffusion in edematous regions disrupts traditional diffusion tensor imaging (DTI), limiting its ability to delineate fiber tracts reliably. This article explores the impact of edema on tractography and reviews recent advancements in diffusion models, including Free Water Imaging (FWI), Neurite Orientation Dispersion and Density Imaging (NODDI), Restriction Spectrum Imaging (RSI), Diffusion Basis Spectrum Imaging (DBSI), and Unscented Kalman Filter (UKF) tractography. These advanced techniques mitigate the limitations of conventional DTI by separating diffusion signals into multiple compartments, utilizing higher b-value encodings, and improving tract in heterogeneous environments. By enhancing the accuracy and reliability of fiber tracking, these approaches have significant implications for clinical applications, particularly in neurosurgical planning and connectivity analysis.