Apparent Diffusion Coefficient and Blood Oxygenation Level Dependent imaging during Neural Activity in the Visual Cortex

Motivation: Diffusion fMRI explores brain dynamics via water ADC variations from cellular fluctuations, distinct from BOLD imaging as it bypasses neurovascular coupling. Despite its potential, dFMRI remains underexplored in fMRI research. Goal(s): The goal of this work is to validate the utility of ADC in fMRI. Approach: Two imaging techniques were utilized: DW-TRSE-EPI and SE-EPI, capturing ADC timecourses and T2-BOLD contrast. The study investigated correlations between a visual paradigm and voxel timecourses. Results: Voxels exhibiting negative ADC and positive BOLD task responses align within the visual cortex. Likewise, voxels displaying positive ADC and negative BOLD responses predominantly align in the default mode network. Impact: Diffusion fMRI could serve as a complementary method to BOLD imaging, both exploring neural activity through distinct approaches.