| 摘要 |
A radio frequency antenna device (30) for use in a magnetic resonance imaging system (10), the magnetic resonance imaging system (10) being configured for acquiring magnetic resonance images of at least a portion of a subject of interest (20); the radio frequency antenna device (30) comprising - at least one radio frequency antennae (32) that is configured for being fed with radio frequency power from at least one radio frequency channel and for applying a radio frequency field B to nuclei of or within the portion of the subject of interest (20) for magnetic resonance excitation, - at least one pickup circuit (46), including an electric or electronic device having a non-linear current-voltage characteristic, - wherein the at least one pickup circuit (46) is configured to provide a trigger signal (56) upon a transfer of the electric or electronic device between a state of high impedance and a state of low impedance, the trigger signal (56) being exploitable for shutting down a supply of radio frequency power to the at least one radio frequency antenna (32) that is magnetically coupled to the at least one inductor (48); a method of operating a magnetic resonance imaging system (10) in a safe manner with regard to effects of emitted radio frequency power; and a method of operating a magnetic resonance imaging system (10) with regard to calibration of a magnitude of an emitted radio frequency magnetic field B1. |
