The disclosure relates to a hybrid orthogonal signal generator, a coil transmission front-end device, an RF coil system, and an MRI system. The hybrid orthogonal signal generator has an input end for receiving an RF signal, generates a hybrid orthogonal excitation signal on the basis of the RF signal, and provides the hybrid orthogonal excitation signal by means of an output end of the hybrid orthogonal signal generator, and comprises: a first conductor, arranged in a plane and being arc-shaped; and a second conductor having mutual inductance with the first conductor, the second conductor being connected between the input end and output end, wherein the first conductor and second conductor are parallel and arranged as mirror images of each other. The hybrid orthogonal signal generator has a compact size and is suitable for providing hybrid orthogonal excitation signals for an MRI system with a low field strength.

In a magnetic resonance apparatus and a method for operation thereof, at least one electrical operating value of at least one predetermined component of the apparatus is captured and, as a function of the at least one operating value, at least one coil operating value of a transmitting coil arrangement of the magnetic resonance apparatus is controlled for the purpose of limiting a B1 value.

Examples of the present disclosure provide methods and devices for monitoring data and provide magnetic resonance systems. According to the examples of the present disclosure, RF waveform information which is to be sent to an RF transmitting coil of the magnetic resonance system is obtained, target waveform information within a current sliding window is extracted from the RF waveform information with a current time point being located within the current sliding window, target magnetic flux densities corresponding to the current sliding window are obtained based on the target waveform information, and a current real-time SAR is determined based on the target magnetic flux densities. Thereby, real time monitoring of the SAR can be achieved by software without additional hardware added into the magnetic resonance system, which reduces the cost of monitoring the SAR.

Disclosed is an MRI control signal providing method including obtaining an initial control variable array including time-series values of a control variable for controlling a spatial profile of an induced magnetic field induced by an MRI scanner, obtaining information about a desired spatial profile of the induced magnetic field in the MRI scanner, calculating a differentiation array obtainable by partially differentiating a predetermined function with respect to the control variable, and calculating a scaled array obtained by scaling the differentiation array with a predetermined scaling factor, and generating an updated control variable array from the initial control variable array by subtracting values of the scaled array from values of the initial control variable array.

A magnetic resonance radio frequency transmission device (140) for generating and applying a radio frequency excitation field B.sub.1 for the purpose of magnetic resonance examination comprises a birdcage coil (144) and a plurality of M radio frequency amplifier units for providing radio frequency power at a magnetic resonance frequency to the birdcage coil (144) via a plurality of M activation ports (158) selected out of the plurality of N activation ports (158). In an operational state of the birdcage coil (144) each radio frequency amplifier unit (142) is electrically connected and is arranged in close proximity to an activation port (158). Among the plurality of M radio frequency amplifier units (142), there is established a fixed relationship of adjustable phase angles (φ) of the magnetic resonance radio frequency power provided by the plurality of M radio frequency amplifier units (142); a method of generating and applying a radio frequency excitation field B for the purpose of magnetic resonance examination, using such magnetic resonance radio frequency transmission device (140); and a magnetic resonance imaging system (110) configured for acquiring magnetic resonance images of at least a portion of a subject of interest (120), comprising such magnetic resonance radio frequency transmission device (140).

Methods for operating a magnetic resonance apparatus and systems therefrom are provided. A method includes generating, via a coil former surrounding a subject or object of interest and disposed in the magnetic resonance apparatus, a plurality of field modes external to the subject or object, measuring for each of the plurality of external field modes, an associated internal field produced within the subject or object, generating, via the coil former a combination of external modes to produce a target internal field in the subject or object, and measuring nuclear magnetic resonance signals due to the resulting field from the combination to acquire an image or spectrum of the subject or object.

A dynamic field camera arrangement for monitoring electromagnetic field behavior in a spatial region comprises a main magnetic field and a radiofrequency (RF) field limited to a first RF band, particularly in an MRI or NMR apparatus. The arrangement comprises a magnetic field detector set comprising a plurality of low-frequency magnetic field detectors, each one of said magnetic field detectors comprising a magnetic resonance (MR) active substance, means for pulsed MR excitation of said substance and means for receiving an MR signal generated by said substance, wherein said pulsed excitation and said MR detector signal is in a second RF band that does not overlap said first RF band. The MR signal receiving means comprise a first RF filter which suppresses RF signal from said first RF band and transmits RF signal from said second RF band.

A magnetic resonance RF receive coil with non-conductive waveguides for data transfer between the RF coil antennas and the channel aggregator is described. The non-conductive waveguide for each channel includes a plastic waveguide transferring data between a millimeter wave transmitter and a millimeter wave receiver.

Systems and Methods for determining a position of an object introduced into a body. An RF pilot tone is generated and is radiated into the body. Response signals modulated by the radiating into the body are received by a plurality of MRI receiver coils arranged spatially distributed outside the body and are converted into respective measurement signals. From the measurement signals, the position of the object is determined.

A control computer for a magnetic resonance imaging system has an analog-to-digital conversion array, a multiplexer array connected to the analog-to-digital conversion array, and a control module that receives at least one input signal via the multiplexer array and the analog-to-digital conversion array. A signal processing board for a magnetic resonance imaging system has a substrate with the aforementioned components thereon that form the aforementioned control computer.