A magnetic resonance imaging apparatus includes a magnetic assembly including a main magnet and a gradient coil unit and forming a static magnetic field and a gradient magnetic field in the bore thereof, and a gradient controller applying a test gradient waveform to the magnetic assembly, and compensating for a distortion of the magnetic field gradients, caused by eddy currents, by reflecting the actual shape of the applied test gradient waveform.

An eddy-current correction method and apparatus, a mobile terminal and a readable storage medium are provided. The method includes: step S1: reading gradient-recalled echo sequence by means of bipolarity, so as to acquire a multi-echo image; step S2: estimating a first-order term coefficient of an extra phase term introduced by an eddy-current in the acquired multi-echo image; step S3: removing the estimated first-order term coefficient, and estimating a zero-order term coefficient of the extra phase term introduced by the eddy-current in the collected multi-echo image; step S4: removing, according to the estimated first-order term coefficient and the zero-order term coefficient, an error of the extra phase term introduced by the eddy-current. The eddy-current correction method removes the phase error caused by the eddy-current in the acquired image, thereby ensuring the correctness of the subsequent water-fat separation algorithm result.

According to some aspects, a laminate panel is provided. The laminate panel comprises at least one laminate layer including at least one non-conductive layer and at least one conductive layer patterned to form at least a portion of a B.sub.0 coil configured to contribute to a B.sub.0 field suitable for use in low-field magnetic resonance imaging (MRI).

An apparatus for controlling at least one gradient coil of a magnetic resonance imaging (MRI) system. The apparatus may include at least one computer hardware processor; and at least one computer-readable storage medium storing processor executable instructions that, when executed by the at least one computer hardware processor, cause the at least one computer hardware processor to perform a method. The method may include receiving information specifying at least one target pulse sequence; determining a corrected pulse sequence to control the at least one gradient coil based on the at least one target pulse sequence and a hysteresis model of induced magnetization in the MRI system caused by operation of the at least one gradient coil; and controlling, using the corrected gradient pulse sequence, the at least one gradient coil to generate one or more gradient pulses for imaging a patient.

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.

An eddy-current correction method and apparatus, a mobile terminal and a readable storage medium are provided. The method includes: step S1: reading gradient-recalled echo sequence by means of bipolarity, so as to acquire a multi-echo image; step S2: estimating a first-order term coefficient of an extra phase term introduced by an eddy-current in the acquired multi-echo image; step S3: removing the estimated first-order term coefficient, and estimating a zero-order term coefficient of the extra phase term introduced by the eddy-current in the collected multi-echo image; step S4: removing, according to the estimated first-order term coefficient and the zero-order term coefficient, an error of the extra phase term introduced by the eddy-current. The eddy-current correction method removes the phase error caused by the eddy-current in the acquired image, thereby ensuring the correctness of the subsequent water-fat separation algorithm result.

In one embodiment, an MRI apparatus includes a scanner and processing circuitry. The scanner includes at least two gradient coils. The processing circuitry is configured to cause the scanner to acquire k-space data for correction in a band-shaped two-dimensional k-space along a readout direction, or in a columnar three-dimensional k-space along a readout direction, while changing rotation angles, wherein each of the rotation angles corresponds to the readout direction, generate correction data for correcting an error due to a gradient magnetic field generated by the gradient coils, by using the acquired k-space data for correction, cause the scanner to acquire k-space data for reconstruction, based on a radial acquisition method, while correcting the gradient magnetic field by using the correction data, and generate an image by reconstructing the acquired k-space data for reconstruction.

A signal processing apparatus according to the present embodiment computes a first integral value corresponding to an element in a coefficient sequence of a first input sequence and a second integral value corresponding to the element in a coefficient sequence of a second input sequence next to the first input sequence, and includes a processing circuitry. The processing circuitry adds a value not overlapping the first input sequence in the second input sequence to the first integral value and subtracts a value not overlapping the second input sequence in the first input sequence from the first integral value for the element, thereby computing the second integral value.

Systems and methods are provided to incorporate an off-resonance correction into the pulse labeling train of PCASL/VEPCASL. In one or more aspects, the systems and methods are based on a method for generating an encoding scheme for any number and arrangement of blood vessels. The off-resonance correction can be incorporated into the generation of optimized encodings to acquire arterial spin labeling (ASL) data, such as PCASL and VEPCASL data.

The invention relates to a magnetic resonance system (100) configured for acquiring magnetic resonance data from a GC subject (118). Execution of the machine executable instructions (140) stored in a memory (134) causes a processor (130) to control the magnetic resonance system (100) using a set of waveform and pulse sequence commands (142, 152) to prepare a first state of vibration (211) of the one or more hardware elements and/or the subject (118). The preparing comprises generating the vibration matching gradient (200) inducing the first vibrations (210) of the one or more hardware elements and/or the subject (118), while the net magnetization vector of the subject (118) is aligned along the longitudinal axis of the main magnetic field. The magnetic resonance system (100) is further controlled to acquire the magnetic resonance data (144, 154) according to a magnetic resonance protocol. The acquiring comprises generating in sequence at least two spin manipulating gradients (202, 204) for manipulating phases of nuclear spins within the subject (118), while the net magnetization vector of the subject (118) comprises a non-vanishing component in a transverse plane perpendicular to the longitudinal axis of the main magnetic field. A first one of the at least two spin manipulating gradients (202) is generated during the first state of vibration (211) and a second one of the at least two spin manipulating gradients (204) is generated during a second state of vibration (213) of the one or more hardware elements and/or the subject (118). The vibration matching gradient (200) is used for matching with the first state of vibration (211) the second state of vibration (213).