Switchable birdcage coil
US7501828B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 2007 |
| Grant date | Mar 10, 2009 |
| Priority date | — |
| Expiry date | Dec 19, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/3657
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A switchable birdcage coil functioning as a transmitter coil and a separate RF surface coil functioning as the receiver coil are utilize in NMR and MRI apparatus. To prevent the switchable birdcage coil from absorbing energy by coupling to the receiver coil or by absorbing power from the RF field produced by the precessing nuclear spins, one or more of the reactive elements of the birdcage coil are switched from a normal reactive impedance state to a high impedance state. The high impedance state is formed by switchably combining the reactive element with a complementary reactive element thereby forming parallel resonant high impedance circuit that is tuned to resonate at the NMR frequency.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.