摘要:
A resonator for magnetic resonance applications has a conductor element that extends from a first conductor end to a second conductor end. During operation of the conductor element at a resonance frequency, a resonance current-oscillates from the first conductor end to the second conductor end and back. The conductor ends are coupled with one another via a circuit that tunes the conductor element to the resonance frequency. The conductor element is fashioned as a multi-layer conductor with a number of layers that have first and second layer ends at the conductor ends. The circuit causes layer currents that are of equal magnitudes to flow in the layers themselves during active operation of the conductor element at the resonance frequency.
摘要:
A selection unit for a magnetic resonance imaging system may be provided. The selection unit electrically connects a first number of electrical terminals to a second number of communication entities. The selection unit is arranged in and/or on a mobile object-support element for moving an examination object which is to be depicted by the magnetic resonance imaging system into a recording position.
摘要:
A magnetic resonance system has multiple individual transmission antennas each charged with a transmission current to emit an individual excitation field in an examination volume to excite magnetic resonances in a subject, producing a total excitation field as a superimposition of the individual excitation fields. A determination device provided with a spatial distribution of an absorption rate of the examination subject, determines a combination of amplitudes and phase positions for the transmission currents relative to one another such that a locally absorbed power at a first point of the examination subject relative to a locally absorbed power at a second point of the examination subject satisfies a relative condition. The determined combination of amplitudes and phase positions are communicated to a control device, which charges the transmission antennas with transmission currents having the communicated phase positions and amplitudes scaled with a uniform scaling factor for all transmission currents relative to the communicated amplitudes.
摘要:
In a magnetic resonance imaging apparatus and method, radio frequency signals are radiated into an examination subject and/or received from the examination subject by an array of radio frequency coils that completely encircles the examination subject, and that is located at a distance from the examination subject out of contact with the examination subject.
摘要:
In a magnetic resonance imaging apparatus and method, radio frequency signals are radiated into an examination subject and/or received from the examination subject by an array of radio frequency coils that completely encircles the examination subject, and that is located at a distance from the examination subject out of contact with the examination subject.
摘要:
A circulator has a ferrite, and the circulator is arranged in the vicinity of a device that produces a static magnetic field in the environment surrounding the device, this static magnetic field giving the circulator a non-reciprocal behavior, with respect to circulation of energy among the gates of the circulator, as a result of interaction of the ferrite with the static magnetic field. A magnetic resonance apparatus embodies such a circulator, and the basic field magnet of this magnetic resonance apparatus generates the static magnetic field.
摘要:
A resonator for magnetic resonance applications has a conductor element proceeding in an extension direction, that operates with a resonance current at a resonance frequency oscillating therein in the extension direction. The conductor element is tuned to the resonance frequency and has an overall length in the extension direction that is smaller than half of the wavelength of the resonance frequency. The conductor element is a multi-layer conductor with layers that are electrically insulated from each other that, in said extension direction, have layer ends that are capacitively coupled with each other. During operation of the conductor element at the resonance frequency, respective layer currents flow in the layers in the extension direction that are substantially equal in magnitude.
摘要:
A resonator for magnetic resonance applications has a conductor element that extends from a first conductor end to a second conductor end. During operation of the conductor element at a resonance frequency, a resonance current oscillates from the first conductor end to the second conductor end and back. The conductor ends are coupled with one another via a circuit that tunes the conductor element to the resonance frequency. The conductor element is fashioned as a multi-layer conductor with a number of layers that exhibit layer ends at the conductor ends. The circuit causes layer currents that are of different magnitudes among one another to flow in the layers during operation of the conductor element at the resonance frequency.
摘要:
An amplifier device for a mode antenna has a number of amplifiers and a number of outputs. An input signal is fed to each amplifier, which is amplified by the respective amplifier into an amplified input signal. The amplified input signals are fed to an output matrix arranged after the amplifiers. Respective output signals are emitted by the output matrix at the outputs. The output matrix causes each amplified input signal to supply an output signal contribution for each output signal. Each output signal contribution of each output signal has an output-side contribution offset in relation to the corresponding amplified input signal, which depends on the amplified input signal that supplied the output signal contribution, and the output signal to which the output signal contribution contributes. The amplifier device is especially able to be used in a transmit arrangement for radio-frequency signals.
摘要:
A magnetic resonance system has a cylindrical patient support unit in the form of a chamber delimited by a wall with a patient bed, as well as at least one flexible flat local coil element with at least one local coil. The local coil element is attached on two opposite sides to mountings accommodated in the chamber. At least one of the mountings at one side is guided to allow movement along the chamber wall, during which manual or automatic movement the local coil element is moved from a storage position adjacent to the wall of the chamber into a position on the patient, or the local coil element attached to the patient bed is able to be moved manually from a storage position to the side or below the patient bed against a return force, into a position on the patient.