| 摘要 |
A local antenna system for generating and receiving circularly-polarized, high-frequency magnetic fields in a nuclear magnetic resonance imaging apparatus has two coil groups disposed to define an examination volume therebetween, with each coil group having two coils therein, with each coil having a middle axis disposed at an angle substantially less than 90 DEG relative to the middle axis of the other coil in that group. The coil groups are disposed relative to the examination volume so that each coil in a coil group has a diagonally disposed counterpart coil in the other coil group. When the diagonally coils are respectively fed with currents which are phase-shifted by 90 DEG relative to each other, they respectively generate circularly-polarized high-frequency magnetic fields in the examination volume which are in-phase. In a reception mode, the signals induced in the diagonally disposed coils are superimposed in-phase.
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