Signal-to-Noise Ratio Improvement by Bi-2223 Surface RF Coil in 0.3T MRI System

A Bi-2223 surface RF coil was developed for a 0.3T permanent MRI system to achieve better signal-to-noise ratio (SNR) of images. Based on the finite element method (FEM), the SNR of a copper-made surface coil is analyzed, and the emphasis is put on the coil self-resistance that accounts for much higher percentage of the equivalent noise resistance in low field MRI than that in high field MRI. In order to improve SNR, a surface coil that is made of a Bi-2223 tape is fabricated for a 0.3T permanent MRI system. Phantom images are acquired, and the image SNR by the Bi-2223 coil in liquid nitrogen is improved by up to 35% compared with that by a copper coil at room temperature.

I. Introduction

The performance of RF coils, which are used to pick up magnetic resonance signals, is significant for imaging quality of MRI systems. The SNR and sensitivity distribution of RF coils are the targets to optimize the coil geometry.