Revisiting the role of structural connectivity in thalamic nuclei segmentation

Motivation: Comparing, contrasting and, combining structural and connectivity based parcellation for thalamic nuclei Goal(s): To parcellate the thalamus using thalamo-cortical connectivity from high-resolution DTI data and state-of-the-art reconstruction and to subdivide pulvinar and mediodorsal thalamus. Approach: Structural T1 and DTI data from 63 HCP young adult subjects were analyzed. Probabilistic tractography followed by a winner-take-all strategy was employed to segment the thalamus based on cortical connections. Results: In addition to global parcellation into 8 or 23 regions, distinct subdivisions within the MD and pulvinar nuclei were also identified. However, connectivity-based methods showed limitations in anatomical accuracy compared to anatomical multi-atlas approaches (THOMAS). Impact: These results advance our understanding of thalamic connectivity, potentially guiding targeted clinical interventions and personalized therapies for neurological conditions. This study enables future research on connectivity-driven parcellation techniques, raising questions about refining segmentation for enhanced anatomical accuracy.