An apparatus and method for receiving a magnetic resonance (MR) signal for imaging a patient. The MR signal includes a MR frequency. A radio frequency (RF) coil has first and second end portions. An impedance converter is in electrical communication with the RF coil. A preamplifier in electrical communication with the impedance converter, the preamplifier having a gain. At least one resonant circuit electrically connected to at least one end portion of the RF coil.

A magnetic resonance tomography scanner with a noise suppressor for suppressing interferences of reception and a method for operation of the magnetic resonance tomography scanner are provided. The noise suppressor receives an interference signal with a sensor, determines a noise suppression signal with a noise suppression controller, and sends the noise suppression signal using a controllable radio frequency amplifier via a transmit antenna, so that the interference signal on a receive antenna of the magnetic resonance tomography scanner is reduced.

Systems and methods for improving output stability of an RFPA. The systems may obtain an initial radio frequency signal to be amplified by the RFPA. The systems may also generate a compensated radio frequency signal by performing, based on a preset compensation rule and a set of compensation parameters, a gain compensation operation for the initial radio frequency signal. The set of compensation parameters may include a supply voltage of the RFPA and a transistor junction temperature of the RFPA. The systems may further generate, by performing a non-linear correction operation on the compensated radio frequency signal, a corrected radio frequency signal, which is transmitted to the RFPA.

An MRI scanner and a method for operation of the MRI scanner are provided. The MRI scanner has a first receiving antenna for receiving a magnetic resonance signal from a patient in a patient tunnel, a second receiving antenna for receiving a signal having the Larmor frequency of the magnetic resonance signal, and a receiver. The second receiving antenna is located outside of the patient tunnel or near an opening thereof. The receiver has a signal connection to the first receiving antenna and the second receiving antenna and is configured to suppress an interference signal by the second receiving antenna in the magnetic resonance signal received by the first receiving antenna.

Various methods and systems are provided for correcting transmit attenuation of an amplifier of a transmit radio frequency (RF) coil for use in a magnetic resonance imaging (MRI) system. In one example, a method includes setting a reference value of transmit attenuation for an amplifier of a transmit radio frequency (RF) coil, acquiring a three-dimensional B.sub.1 field map with the transmit attenuation set at the reference value, determining a plurality of mean flip angles for a plurality of slice locations in a pre-scan imaging volume from the B.sub.1 field map, determining a transmit attenuation correction value for each of the slice locations based on a prescribed flip angle and the mean flip angle determined for the respective slice location, correcting the reference value of transmit attenuation with the transmit attenuation correction value at each of the slice locations to obtain a final value of transmit attenuation for each of the slice locations, and performing an MRI scan with the transmit attenuation set at the value.

The invention relates to the generation of RF pulses for MRI applications. According to the invention, a RF transmitter for a MRI system (1) is provided which comprises a RF amplifier (9) for generating RF pulses and for forwarding these RF pulses to a RF transmit coil (5) of the MRI system (1), a capacitor bank (10) coupled to the RF amplifier (9), for storing electric energy and for providing the RF amplifier (9) with a current for generating the RF pulses, a mains power supply (11) coupled to the capacitor bank (10), for generating a charging current for charging the capacitor bank (10) with electric energy, and a power supply control unit (12) coupled to the mains power supply (11), for controlling the generation of the charging current for the capacitor bank (10), wherein the power supply control unit (12) is adapted for receiving an indication signal indicating the actual and/or the upcoming current drawn from the capacitor bank (10) and for controlling the generation of the charging current for the capacitor bank (10) on the basis of the indication signal. In this way, the generation of RF pulses for MRI applications becomes more efficient making it possible to use smaller capacitor bank values at the same performance level.

A magnetic resonance detection (MRD) system for and methods of detecting and classifying multiple chemical substances is disclosed. In one example, the presently disclosed MRD system is a nuclear quadrupole resonance (NQR) detection system that provides multi-frequency operation for substantially full coverage of the explosive NQR spectrum using a broadband transmit/receive (T/R) switch (or duplexer) and a single multi-frequency radio frequency (RF) transducer. More particularly, the MRD system provides a frequency-agile system that can operate over a wide band of frequencies or wavelengths. Further, a method of detecting and classifying various chemical substances is provided that includes pulse sequencing with “frequency hopping,” phase cycling for reducing or substantially eliminating background noise, and/or a process of mitigating amplitude modulation (AM) radio interference.

Provided in the present invention are a linear compensation method for a radio frequency amplifier and a magnetic resonance imaging system. The linear compensation method for a radio frequency amplifier includes determining a working voltage of the radio frequency amplifier, determining a corresponding linear compensation value based on the working voltage, and performing linear compensation on the radio frequency amplifier based on the linear compensation value.

Embodiments of the present application provide a magnetic resonance system and a transmission apparatus, a transmission method, and a pre-scanning method. The apparatus includes: a signal output unit used to generate and output a pulse signal; a radio-frequency amplifier used to amplify the pulse signal; a signal processing unit used to transmit, to a transmit coil of the magnetic resonance system, the signal amplified by the radio-frequency amplifier, receive and adjust a phase of the feedback signal, and output the phase-adjusted feedback signal to the signal output unit; and a determination unit used to acquire amplitude values of the feedback signal at different phases, and determine a forward power and/or a reverse power according to the amplitude values of the feedback signal at the different phases.

A radio frequency amplifying device according to an embodiment includes load impedance calculating circuitry and controlling circuitry. The load impedance calculating circuitry is configured to calculate a load impedance on the basis of information about a voltage standing wave rate and a phase on an output side of radio frequency amplifying circuitry. The controlling circuitry is configured to adjust a gain and a phase of a signal to be input to the radio frequency amplifying circuitry, in accordance with the load impedance calculated by the load impedance calculating circuitry.