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.

Techniques are disclosed for a local coil and a magnetic resonance imaging system. The local coil includes a plurality of coil units that respectively receive magnetic resonance signals generated when magnetic resonance detection is performed on a detected object, and a signal processing unit configured to perform processing including signal preprocessing and quadrature modulation on the magnetic resonance signals received by the plurality of coil units to obtain signals to be transmitted. Contactless connectors are also disclosed, each being configured to couple the signals to be transmitted to a contactless connector at the MR system side.

The present disclosure is directed to a device and a magnetic resonance system for concentrating a magnetic field of radio frequency signals, and methods for concentrating a magnetic field of as radio frequency signal in an object to be imaged.

A system includes a machine readable storage medium storing instructions and a processor to execute the instructions. The processor executes the instructions to receive radial k-space magnetic resonance imaging (MRI) data of a patient and determine a series of dipole sources via direct dipole decomposition of the radial k-space MRI data. The processor executes the instructions to identify an activation within the patient based on the series of dipole sources.

An electric circuit arrangement for energizing a magnet of a magnetic resonance imaging facility includes a first circuit part, a second circuit part and a control facility. In an embodiment, the first circuit part is designed to generate a direct voltage as an DC link voltage from an alternating voltage and the second circuit part is designed as a current source fed by the DC link voltage. The second circuit part includes a down converter controllable by the control facility, a transformer switchable by the control facility and a rectifier. A primary current is generatable from the DC link voltage via the down converter. The primary current is feedable by a switching facility, switched by the control facility into a primary side of the transformer, and a secondary current for energizing the magnet is generatable via the rectifier connected to a secondary side of the transformer.

A magnetic resonance tomography unit includes a transmitter, a transmission monitoring device for monitoring an excitation signal from the transmitter, and a plurality of transmit antennas. The magnetic resonance tomography unit also includes a switching device configured to bring the transmission monitoring device selectively into a signal connection to one transmit antenna of the plurality of transmit antennas. A method for operating the magnetic resonance tomography unit is also provided.

An MRI system coil insert 2 for use within a bore B of a main MRI system 1, the coil insert 2 comprising at least one gradient coil, for creating a spatially varying magnetic field along a respective axis and being arranged to be electrically driven at an ultrasonic frequency.

Encapsulation packages for stent-deployable monitoring devices formed of resonator sensors and allowing for magnetic biasing elements that exhibit a targeted impact on the mechanical characteristics of a stent are provided. Encapsulation packages are formed of different types and include a longitudinal shield and curved end on profile for aligning the shield within the deployable stent, the shield having perforations such that a resonator can be positioned adjacent the perforations for allowing particulate within the stent to collect and be measured by the resonator during deployment.

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.