Finite-Element Electromagnetic Simulation of a Volume Coil with Slotted End-Rings for Magnetic Resonance Imaging

Abstract

Radiofrequency volume coils are still a vital part to detect the magnetic resonance signal. This is mainly due to its highly uniform field over large regions of interest at expense of a relatively low signal‐to‐noise ratio. In this work, a new volume coil design with slotted end‐rings is proposed for high field magnetic resonance imaging applications and, its electromagnetic properties studied via a numerical study. The slotted end‐rings avoid breaking the coil structure into small segments degrading the coil performance and, improving the poor signal at the end‐rings usually found in the traditional birdcage coil. Numerical simulations were evaluated by solving Maxwell's equations with the finite element method. Hence, both the electric and magnetic fields were evaluated and presented in the form of bi‐dimensional images for the slotted end‐ring coil and the birdcage coil for comparison purposes. From the magnetic field images of both coil designs, uniformity profiles were calculated at the midsection and the end‐rings of the coil and compared. A substantial improvement can be appreciated at the end‐rings for the slotted end‐ring coil whereas for the midsection it had an acceptable enhancement. These encouraging results suggest that the slotted end‐ring coil have an improved performance compared to the birdcage coil.