Pascone R, Vullo T, Farrelly J, Cahill P T
Department of Electrical Engineering, Manhattan College, Riverdale, NY 10471.
Magn Reson Imaging. 1992;10(3):401-10. doi: 10.1016/0730-725x(92)90511-w.
A formulation has been developed for the determination of self and mutual inductances in unloaded, eight-column symmetric birdcage coils using their expected resonant mode current patterns and well-known inductance formulas. The average frequency differences between theory and experiment for mode one resonances for nine low-pass coils were 0.66 (+/- 0.57) MHz and 2.14 (+/- 2.08) MHz using effective (self plus mutual) and self inductances, respectively, and similarly, for three high-pass coils, 1.19 (+/- 0.56) MHz and 2.79 (+/- 2.20) MHz. These frequency differences were more pronounced for the higher modes; for mode four, the differences neglecting mutual inductance were 14.30 (+/- 11.10) MHz and 10.42 (+/- 4.60) MHz for the low- and high-pass coils, respectively. This analysis provides the first explicit evaluation of the total end-ring and column inductances L1 and L2 within each birdcage section at resonance with resulting excellent agreement in resonant frequencies between theory and experiment.
已开发出一种方法，利用空载八柱对称鸟笼线圈的预期谐振模式电流分布和著名的电感公式来确定自感和互感。对于九个低通线圈，使用有效（自感加互感）电感和自感时，模式一谐振的理论与实验平均频率差分别为0.66（±0.57）MHz和2.14（±2.08）MHz；同样，对于三个高通线圈，分别为1.19（±0.56）MHz和2.79（±2.20）MHz。这些频率差在更高模式下更为明显；对于模式四，忽略互感时，低通和高通线圈的频率差分别为14.30（±11.10）MHz和10.42（±4.60）MHz。该分析首次明确评估了每个鸟笼部分在谐振时的总端环电感和柱电感L1和L2，理论与实验的谐振频率结果吻合良好。
