Comparison of Four Different Birdcage Type Coils
Collins C, Liu W, Smith M
Penn State College of Medicine
Four birdcage-type coils are built to experimentally examine the effects of the end-ring/shield configuration on SNR in a head at 125 MHz. The configurations include a) a conventional shield (conventional), b) a shield with annular extensions to closely shield the end-rings (surrounding shield), c) a shield with annular extensions connected to the rungs (solid connection), and d) a shield with strips of copper tape connected to the rungs(thin wire connection). In a human head, the conventional and the surrounding shield configuration result in higher SNR than the solid connection configuration, which has a SNR higher than the thin wire configuration.