A high permittivity and conformable gel pad fabricated by the PVA freeze-thaw method for dielectric shimming in ultra-high-field MRI

Motivation: Utilize new material to fabricate high-permittivity pads for addressing the B1 inhomogeneity and safety issues in ultra-high-field MRI scanning. Goal(s): We aim to develop a new high permittivity pad with flexibility which can fit various body shapes. Different sizes and mass proportions of barium titanate powder were explored to achieve optimized mechanical properties and desired permittivity value. Approach: The gel pad is fabricated using the PVA freeze-thaw method, resulting in a stable gel structure that incorporates barium titanate powder, thereby possessing excellent mechanical properties and high permittivity. Results: Experimental results demonstrate of the gel pad's potential for clinical applications in ultra-high-field MRI scanning. Impact: This abstract introduces a novel gel pad with high permittivity that can be conformed to different shapes of scanned objects. It highlights the potential of the gel pad in addressing safety issues in ultra-high-field MRI scanning.