Investigation of the Relationship Between Electrical Conductivity, Diffusivity, and Tissue Volume in the Aging Brain

Motivation: This study provides novel insights into the intricate relationships between brain electrical conductivity, diffusivity, and tissue volume in elderly individuals. Goal(s): To explore the relationships between electrical conductivity, diffusivity, and brain tissue volume in the aging brain. Approach: With 77 patients, brain MREPT and DTI were employed to calculate high-frequency conductivity (HFC) and separate it into extra-neurite (EC) and intra-neurite (IC) conductivities. Results: Multiple regression revealed a positive association of both HFC and EC with MD, RD, and axial diffusivity (AxD) in the hippocampus and insula. IC correlated positively with intra-neurite diffusivity (ID) in the amygdala, thalamus, and insula. Impact: This research underscores the importance of distinguishing between conductivity and diffusion changes when interpreting clinical MREPT data.