Preliminary Study on Functional MRI-Related Conductivity and Permittivity Changes using Electrical Properties Tomography

Motivation: While MRI signal intensity is influenced by |B1+|, fMRI-related changes in permittivity, which are related to |B1+| distributions, have not yet been investigated. Goal(s): Observing fMRI-related changes in conductivity and permittivity, and simulating to verify whether fMRI effects arise solely from electrical properties changes. Approach: With AFI and bSSFP sequences, |B1+| and φ± are acquired to reconstruct the electrical properties (σ and εr) via electrical properties tomography. Simulations were utilized to validate the B1 field and reconstructed electrical properties. Results: Activated correlations are observed between brain activation and electrical properties, with simulations demonstrating that changes in electrical properties can mimic fMRI effects. Impact: Functional MRI-related changes in both electrical conductivity and permittivity are observed during brain activation, potentially enhancing our understanding of the relationships between fMRI effect, vascular factors, and tissue electrical properties.