In one embodiment, a receiving coil includes at least one coil element that can simultaneously receive a plurality of magnetic resonance signals having different frequencies, wherein a resonance structure for the different frequencies is provided in a single plane in each of the at least one coil element.

Methods, systems, and techniques for a field modification device for modifying a transmission field (Tx) and/or a receive field (Rx) used by an MR system are provided. The field modification device comprises a plurality of resonator elements being inducible by the transmission field and/or the receive field to resonate, thereby modifying the transmission field and/or the receive field, respectively, wherein a respective resonance frequency and/or resonance phase of a respective resonator element and/or of a respective group of resonator elements is individually controllable. The field modification device further comprises a device controller configured to individually control the respective resonance frequency and/or resonance phase of the respective resonator element and/or of the respective group of resonator elements .

In a frequency converter, a transmission signal having a first frequency component and a second frequency component is multiplied by a local signal, to thereby frequency-convert the transmission signal. In a power amplifier, the frequency-converted transmission signal is amplified. A demultiplexing circuit generates a first transmission signal and a second transmission signal from the amplified transmission signal. A controller is configured to set for a transmission section a frequency set suitable for two irradiation frequencies.

A magnetic resonance coil and a magnetic resonance imaging system using the same are provided. The magnetic resonance coil may include an antenna, an amplifier, and a protective circuit. The antenna may be configured to receive a radio frequency (RF) signal emitted from an object. The antenna may not resonate with the RF signal. The amplifier operably coupled to the antenna configured to amplify the RF signal. The protective circuit may be configured to protect the antenna and the amplifier.

A device is for checking the authenticity of an areal data carrier having a zero-field nuclear magnetic resonance feature, having one or more excitation coils for producing excitation pulses for the zero-field NMR feature, an array of multiple receiver coils that are independent of the excitation coils and are at least partially arranged adjacent to each other for the spatially resolved detection of the signal response of the zero-field NMR feature, the number of receiver coils in the receiver coil array being greater than the number of excitation coils, and the area covered by the excitation coils at least partially covering the area covered by the receiver coils in the receiver coil array and exceeding the size of said area.

A method is provided for calibration of a magnetic resonance device with a transmitting device for generating an excitation field. In a first acquisition phase, a first transmitting coil element is detuned, at least one second transmitting coil element is tuned, and an MR data set is acquired using the transmitting device. In a second acquisition phase, the first transmitting coil element, the at least one second transmitting coil element are tuned, and at least one further MR data set is acquired using the transmitting device. By an arithmetic unit, a calibration factor is determined based on the MR data set and the at least one further MR data set for calculating a total voltage value at a feeding point of the first transmitting coil element from voltage values, which may be measured at a measuring point of an electrical supply line of the first transmitting coil element.

A magnetic resonance imaging apparatus includes a T/R switch. The T/R switch includes a double sided microstripline based hybrid couplers with a top side and a bottom side each including two concentric microstripline based hybrid couplers. Each of the two concentric microstripline based hybrid couplers includes an inner microstripline based hybrid coupler and an outer microstripline based hybrid coupler. The inner microstripline based hybrid coupler forms an inner loop of the two concentric microstripline based hybrid couplers and the outer microstripline based hybrid coupler forms an outer loop. In a transmission mode, the inner microstripline based hybrid coupler and the outer microstripline based hybrid coupler at the top side of the dual-tuned T/R switch are activated. In a receiving mode the inner microstripline based hybrid coupler and the outer microstripline based hybrid coupler at the top side and at the bottom side of the dual-tuned T/R switch are activated.

A method of operating a magnetic resonance imaging (MRI) apparatus includes exciting a body coil of the MRI apparatus to emit a radio-frequency signal, determining a center frequency of a resonance curve of the body coil, and calculating a magnet target frequency based on the determined center frequency. A magnet is ramped to the magnet target frequency.

A magnetic resonance imaging apparatus includes a T/R switch. The T/R switch includes a double sided microstripline based hybrid couplers with a top side and a bottom side each including two concentric microstripline based hybrid couplers. Each of the two concentric microstripline based hybrid couplers includes an inner microstripline based hybrid coupler and an outer microstripline based hybrid coupler. The inner microstripline based hybrid coupler forms an inner loop of the two concentric microstripline based hybrid couplers and the outer microstripline based hybrid coupler forms an outer loop. In a transmission mode, the inner microstripline based hybrid coupler and the outer microstripline based hybrid coupler at the top side of the dual-tuned T/R switch are activated. In a receiving mode the inner microstripline based hybrid coupler and the outer microstripline based hybrid coupler at the top side and at the bottom side of the dual-tuned T/R switch are activated.

An apparatus for increasing efficiency in the transmission phase and sensitivity in the reception phase, in specific regions of space, of magnetic resonance imaging technique by using at least one metamaterial or dielectric material is provided. Placing the metamaterial or dielectric material in a suitable geometry, in the space delimited by an RF coil and a sample, allows using the surface plasmonic resonances or equivalent dielectric resonances, induced in the metamaterial or dielectric material by the RF coil, to amplify the intensity of the magnetic field in the spatial region of the sample, improving the intensity of the signal transmission and/or the sensitivity of detection. The metamaterial or dielectric material is positioned outside the RF coil to maximize the amplification effect.