  High impedance RF coils, such as self-decoupled coils, reduce the
electromagnetic coupling between the coil elements and eliminates the use of
complex decoupling technologies. Although the high impedance design promises
excellent decoupling between the coil elements, it also results in high
electric fields across the RF coil, leading to potential safety problems during
imaging. It also causes B1 field asymmetry, ultimately leading to difficulties
in imaging quantification. In this study, we propose and investigate using a
high dielectric sheet to reduce the electric fields across the coil and achieve
excellent electromagnetic decoupling among the coil elements, thereby ensuring
safer MRI at ultra-high fields and maintaining high imaging performance.
