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 magnetic resonance imaging (MRI) system and method for acquiring magnetic resonance (MR) images using a pulse sequence implementing driven equilibrium and quadratic phase cycling techniques is provided. The method includes, during a pulse repetition period of a pulse sequence and using a quadratic phase cycling scheme, applying a first RF pulse to deflect a net magnetization vector associated with the subject from a longitudinal plane into a transverse plane; after applying the first RF pulse, applying a first sequence of RF pulses each of which flips the net magnetization vector by approximately 180 degrees within the transverse plane; and after applying the first sequence of RF pulses, applying a second RF pulse to deflect the net magnetization vector from the transverse plane to the longitudinal plane.

Methods, devices, and systems for data monitoring are provided. In one aspect, a method of data monitoring, applicable to a magnetic resonance system, includes: obtaining radio frequency (RF) waveform information which is to be sent to an RF transmitting coil of the magnetic resonance system; extracting target waveform information within a current sliding window from the RF waveform information, with a current time point being located within the current sliding window; obtaining, based on the target waveform information, target magnetic flux densities corresponding to the current sliding window; and determining a current real-time specific absorption rate (SAR) based on the target magnetic flux densities.

Phase-incrementing MRSI (pi-MRSI) method has resolved overlapping biomarker images in the presence of a read-gradient. On a Bruker 9.4T MRI spectrometer, the pi-SEE-HSelMQC sequence was implemented. The choline-selective and lactate CH-selective RF pulses were phase incremented by 10° in opposite signs, synchronized with the phase-encoding steps. The lactate and choline images from a yogurt phantom displayed opposite image offsets without image overlapping. In vivo one-dimensional pi-SEE-HSelMQC CSI images of lactate and choline, acquired from the MDA-MB-231 human breast cancer xenograft in a nude mouse, as well as two-dimensional pi-SEE-HSelMQC imaging of lactate and choline acquired from the PC3 human prostate cancer xenograft in a nude mouse, also had opposite image offsets, shifted away from the spurious residual water signals in the image center. The pi-SEE-HSelMQC method completely suppresses lipid and water with potential clinical applications in disease diagnosis and therapeutic interventions.

A technique and associated imaging system is provided that selectively acquires the myelin water signal by utilizing a multiple inversion RF pulses to suppress a range of long T.sub.1 components including those from axonal and extracellular water. This leaves the myelin water, which has been suggested to have short T.sub.1, as the primary source of the image. After long T.sub.1 suppression, the resulting image is dominated by short T.sub.2 in the range of the myelin water (T.sub.2*<20 ms at 3 T). This result confirms that the short T.sub.1 component has short T.sub.2* and, therefore, the resulting image is a myelin water image.

A transmitter for a magnetic resonance (MR) system, such as nuclear magnetic resonance (NMR) system, is described herein. The transmitter includes a coil for applying NMR pulse sequences to a substance. The coil includes a first coil section and a second coil section. The first coil section and second coil section pass current in opposite polarity. The transmitter may also include a transmitter circuit for generating the NMR pulse sequences and providing the NMR pulse sequences to the coil. The transmitter circuit includes a first switch that selectively powers the first coil section and a second switch that selectively powers the second coil section. Operation of the first switch and the second switch generates the NMR pulse sequences.

In a method and apparatus for acquiring a magnetic resonance image data set of a scan area of an examination subject, the image data are acquired with a magnetic resonance apparatus having a transmitter coil that emits a radio-frequency signal having at least two transmission channels so that different polarizations of the radio-frequency signal are produced, and a magnetic resonance sequence is used to acquire raw data for the magnetic resonance image data set, wherein raw data are acquired during at least two scanning operations with the magnetic resonance sequence, with different polarizations of the radio-frequency signals being used for at least two of the at least two scanning operations, following which the magnetic resonance image data set is determined by averaging the raw data.

In a magnetic resonance imaging apparatus and a method for the operation thereof, a diagnostic magnetic resonance imaging sequence is selected in a control computer of the apparatus, and an adjustment parameter for the selected sequence is acquired in the control computer, which is specific to the subject under examination. A limit value for a loading parameter of the subject is specified in the computer, and a parameter range for an imaging parameter of the sequence is determined in the computer on the basis of the acquired adjustment parameter and the specified limit value for the loading parameter. A planning environment for the magnetic resonance imaging of the subject is presented, in which only the determined parameter range can be set for the imaging parameter.

A method for controlling a signal with a plurality of independent components is provided. The signal is fed as an input signal via an input path to a control path that supplies an output signal. The output signal is fed via an output path to a control apparatus controlling the input signal. A coupling signal is determined in a coupling determination apparatus. On the basis of the coupling signal, the independent components are decoupled in a decoupling apparatus, as a result of which, a decoupled output signal is generated. Components of the decoupled output signal are decoupled from the components of the input signal. The decoupled output signal is fed as a control variable to the control apparatus. The control apparatus controls each independent component separately on the basis of a desired signal with a diagonal controller and outputs the input signal as a manipulated variable.

The invention relates to a method for optimization of a performance of a multi-channel transmitter including several transmit elements, particularly in a magnetic resonance imaging device. The method includes: (a) Exciting the transmit elements of the multi-channel transmitter by electric excitation signals comprising a specific power, with the power of the excitation signals partially reflected by the transmit elements of the multichannel transmitter, (b) Determining a reflected power which is reflected by the multi-channel transmitter during excitation of the transmit elements, (c) Determining reflection coefficients S.sub.xx of the multi-channel transmitter, (d) Determining reflection coefficients S.sub.xy of the multi-channel transmitter, (e) Calculating a performance criterion representing the performance of the multi-channel transmitter, with the performance criterion based on the reflected power, the reflection coefficients S.sub.xx and the reflection coefficients S.sub.xy, and (f) Tuning the multi-channel transmitter so that the performance criterion is optimized.