发明授权
- 专利标题: Circularly polarizing local antenna for a nuclear magnetic resonance imaging apparatus
- 专利标题(中): 核磁共振成像装置的圆周极化天线
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申请号: US933735申请日: 1992-08-24
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公开(公告)号: US5241272A公开(公告)日: 1993-08-31
- 发明人: Axel Friedrich
- 申请人: Axel Friedrich
- 申请人地址: DEX Munich
- 专利权人: Siemens Aktiengesellschaft
- 当前专利权人: Siemens Aktiengesellschaft
- 当前专利权人地址: DEX Munich
- 优先权: DEX4128323 19910827
- 主分类号: A61B5/055
- IPC分类号: A61B5/055 ; G01R33/34 ; G01R33/341
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.degree. 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.degree. 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.