Mapping Human Corpus Callosum Connectivity With Diffusion Spectrum Imaging: A Deterministic Tractography Approach

To establish a high-resolution atlas of the corpus callosum (CC) using diffusion spectrum imaging (DSI), aiming to detail the subregional connectivity and improve the understanding of interhemispheric communication for clinical applications.

This research employed DSI in conjunction with quantitative anisotropy (QA)-based deterministic fiber tracking on 44 healthy individuals to map the connectivity patterns of the CC, correlating these with cortical subregions defined in the automated anatomical labeling (AAL) and human brainnetome atlas (BNA).

The study identified 41 regions corresponding to the AAL atlas and 101 regions related to the BNA atlas at the midsagittal plane of the CC. Specifically, it included 34 frontal subregions associated with higher brain functions located predominantly in the anterior part of the CC. The midbody of the CC harbored subregions related to primary motor and sensory functions, while the splenium was characterized by subregions containing temporal projections. This comprehensive mapping revealed a complex and nuanced connectivity pattern within the CC, highlighting significant heterogeneity across regions that reflects its diverse structural and functional roles in brain functionality.

The developed atlas represents the first extensive mapping of the CC integrating both anatomical and functional connectivity paradigms, using QA-based DSI deterministic tractography. This atlas, which will be freely available, provides a valuable resource for neuroscientific research and clinical practice, offering detailed insights into the structural and functional organization of the CC.