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.