Systems and methods for magnetic resonance imaging, including adjusting spatial distribution of a rotating magnetic field. By minimizing imaging time, the B.sub.1 nonuniformity reducing effect of RF shimming is maximized for an imaging section of an arbitrary axis direction and an arbitrary position. B.sub.1 distributions are measured for only several sections of one predetermined direction, and a radio frequency magnetic field condition that maximizes the B.sub.1 non-uniformity reducing effect for an imaging section of an arbitrary direction and an arbitrary position is calculated from the B.sub.1 distribution data.

Described here are systems and methods for producing images with a magnetic resonance imaging (“MRI”) system using a high-resolution, motion-robust, artifact-free segmented echo planar imaging (“EPI”) technique. In particular, a fast low angle excitation echo planar imaging technique (“FLEET”) using variable flip angle (“VFA”) radio frequency (“RF”) excitation pulses that are specifically designed to have a flat magnitude and phase profile across a slice for a range of different flip angles.

According to one embodiment, a magnetic resonance imaging apparatus includes processing circuitry. The processing circuitry calculates power of a first RF magnetic field required for excitation at a first flip angle in a first target slice, acquires information on inhomogeneity of a transmission RF magnetic field for a cross section crossing the first target slice, and calculate power of a second RF magnetic field required for excitation at a second flip angle in a second target slice different from the first target slice for the cross section by using the information and the first RF magnetic field power.

The present invention relates to an RF transmit system and method, MRI system and a pre-scan method and medium thereof. The RF transmit system comprises: an RF output unit, for generating and outputting an RF pulse signal; an RF amplifier, for amplifying the RF pulse signal; and a signal processing unit, for communicating the amplified RF pulse signal to an RF transmit coil of the MRI system and outputting a feedback signal to the RF output unit, wherein the RF output unit generates a linearity compensation control signal based on the feedback signal and a predetermined feedback signal-linearity compensation value-relationship, so as to carry out linearity compensation for the RF pulse signal outputted by the RF output unit. The RF transmit method corresponds to the above noted system and the MRI system comprises the above noted RF transmit system. The pre-scan method comprises the RF transmit method. Instructions recorded by the medium may execute the above noted RF transmit method and pre-scan method.

A magnetic resonance imaging apparatus includes: a radio frequency (RF) coil including an endring; a power source configured to respectively supply RF power to each of a first port and a second port of the endring; three probes arranged adjacent to the endring; a voltage detector configured to detect the amplitudes of respective voltages induced to each of the three probes; and a controller configured to estimate a current of the RF coil based on the detected amplitudes of the respective voltages.

A system acquires MR image data of a portion of patient anatomy associated with spin lattice relaxation time in a rotating frame using an RF (Radio Frequency) signal generator and a magnetic field gradient generator. The RF (Radio Frequency) signal generator generates RF excitation pulses in anatomy and enables subsequent acquisition of associated RF echo data. The magnetic field gradient generator generates anatomical volume select magnetic field gradients for phase encoding and readout RF data acquisition in a three dimensional (3D) anatomical volume. The RF signal generator and the gradient generator use in order, a saturation pulse, a T1 spin lattice relaxation rotating frame preparation pulse sequence and a spoiler gradient, in acquiring image data of the 3D volume showing luminance contrast associated with T1 spin lattice relaxation in a rotating frame.

Determining parameter values in image points of an examination object in an MR system by an MRF technique. Comparison signal waveforms, established using predetermined recording parameters, and each assigned to predetermined values of the parameters to be determined, are loaded. An image point time series of the examination object is acquired with an MRF recording method such that the acquired image point time series are comparable with the loaded comparison signal waveforms. A signal comparison of a section of the respective signal waveform of the acquired one image point time series is carried out with a corresponding section of loaded comparison signal waveforms to establish similarity values. The values of the parameters to be determined on the basis of the most similar comparison signal waveforms determined are determined, and then stored or output.

The present disclosure is directed to controlling a magnetic resonance imaging system for generating magnetic resonance image data from an object under examination, in which magnetic resonance raw data is captured, and at least one multi-slice STEAM pulse sequence is generated. The multi-slice STEAM pulse sequence comprises one excitation module for each slice, in each of which are generated a first slice-selective RF excitation pulse and a second slice-selective RF pulse, and one readout module for each slice for acquiring magnetic resonance raw data, which readout module comprises a third slice-selective RF pulse and further sequence elements for spatial encoding and for receiving RF signals. Between the excitation module and the readout module of a first slice is implemented at least one excitation module or one readout module for another slice.

In a method for generation of a homogenization field suitable for homogenization of magnetic resonance data of an examination object, first magnetic resonance data from an examination region of the examination object is provided, a trained function is provided, a homogenization field is extracted by processing the first magnetic resonance data by way of the trained function, and the homogenization field is provided.

Provided in the present invention are a power control apparatus for a radio-frequency power amplifier and a radio-frequency transmission system for a magnetic resonance imaging system. The power control apparatus comprises: a power control module used to receive a control voltage so as to control an output power of the radio-frequency power amplifier; a voltage detection module used to detect an operating voltage provided to the radio-frequency power amplifier and to output a detected voltage; and a voltage adjustment module used to adjust, on the basis of the detected voltage, the control voltage received by the power control module so as to adjust the output power of the radio-frequency power amplifier.