A number of repetitions of a magnetic resonance measurement sequence and a number of repetitions of a navigator magnetic resonance measurement sequence are executed in a interleaved manner. Each repetition of the magnetic resonance measurement sequence includes the time-parallel creation of gradient echoes for measurement of magnetic resonance data. Each repetition of the navigator magnetic resonance measurement sequence includes the radiating of RF excitation pulse, the activation of at least one gradient pulse train for time-sequential creation of gradient echoes, and the read out of the gradient echoes as navigator magnetic resonance data. The magnetic resonance data are modified based on the navigator magnetic resonance data. This enables an N/2 ghosting artifact and/or a constant magnetic field drift and/or a movement artifact to be reduced. Such techniques can be applied in conjunction with simultaneous multi-slice echo planar magnetic resonance imaging, SMS EPI. Diffusion-weighted magnetic resonance imaging also is possible.

A magnetic resonance imaging apparatus according to one embodiment includes a sequence controller, a correction map generator, an image generator, and a corrector. The sequence controller executes first data acquisition to acquire data for a phase correction map, and second data acquisition to acquire data of a cluster of images corresponding to a plurality of time phases. The correction map generator generates the phase correction map by using echo signals acquired through the first data acquisition. The image generator generates the cluster of images corresponding to the time phases by using echo signals acquired through the second data acquisition. The corrector corrects a phase of each image included in the cluster of images, based on the phase correction map and changes in phase of echo signals that occur between time phases.

A magnetic resonance imaging (MRI) apparatus for obtaining a magnetic resonance (MR) image, based on a multi-echo sequence, and a method of the MRI apparatus are provided. The MRI apparatus includes a data obtainer configured to obtain first echo data, based on an echo that is generated at a first echo time, and obtain second echo data, based on an echo that is generated at a second echo time later than the first echo time, the first echo data including a part overlapping a part included in the second echo data in a k-space. The MRI apparatus further includes an image processor configured to reconstruct the MR image, based on the first echo data and the second echo data.

In a magnetic resonance imaging apparatus, a transmission RF coil is configured to emit an RF pulse generated by using a first clock. In addition to an echo signal emitted from a patient, a reception RF coil is configured to further receive the RF pulse emitted by the transmission RF coil and configured to transmit, via a wireless communication, a multiplexed signal in which the echo signal digitalized by using a second clock, the RF pulse, and the second clock are multiplexed together. Wireless receiving circuitry is configured to receive the multiplexed signal via a wireless communication. Correcting circuitry is configured to correct the phase of the echo signal on the basis of the RF pulse and the second clock restored from the multiplexed signal received via the wireless communication. Reconstructing circuitry is configured to reconstruct an image by using the corrected echo signal.

In a magnetic resonance method and apparatus for generating diffusion-weighted image data, at least two recordings are implemented in which raw data are acquired at raw data points of a raw data memory weighted with a b-value. The raw data memory has a first subregion and a second subregion, the first subregion being more than half of the total raw data points of the raw data memory. In each of the at least two recordings of the first subregion, full sampling takes place, and the second subregion is differently undersampled in the respective recordings. The raw data are combined and reconstructed into image data weighted with the b-value.

A magnetic resonance imaging (MRI) system (600) obtains magnetic resonance (MR) images of a volume. The MRI system includes at least one controller (610) configured to perform a preparation scan (103, 301) to acquire preparation echo phase information (105, PEPI) for a plurality of dynamics of a scan (300); output a plurality of pulse sequences (200), each pulse sequence is configured for a corresponding dynamic of the plurality of dynamics of the scan and includes a navigator sequence (204) and an image sequence (206); acquire navigation and image information (111, 117) for each corresponding pulse sequence of the plurality of pulse sequences; and/or form corrected image information (125) by correcting echo phase information in accordance with the preparation echo phase information, correcting at least one of gradient delay or frequency offset of the image information in accordance with the navigation information.

In an EPI acquisition sequence for magnetic resonance signals k-space is scanned along sets of lines in k-space along opposite propagation directions, e.g. odd and even lines in k-space. Phase errors that occur due to the opposite propagation directions are corrected for in a SENSE-type parallel imaging reconstruction. The phase error distribution in image space may be initially estimated, calculated form the phase difference between images reconstructed from magnetic resonance signals acquired from the respective sets of k-space lines, or from an earlier dynamic.

A method and system for reducing Nyquist ghost artifact is provide. The method may include: obtaining a plurality of measured data sets; determining, based on the plurality of measured data sets, in a data space, a plurality of convolution kernels, each convolution kernel relating to all of the plurality of measured data sets; generating, based on the plurality of convolution kernels and the plurality of measured data sets, in the data space, a plurality of synthetic data sets; generating, based on the plurality of synthetic data sets and the plurality of measured data sets, in the data space, a plurality of combined data sets, each combined data set relating to one of the plurality of synthetic data sets and a corresponding measured data set of the plurality of measured data sets; and reconstructing, based on the plurality of combined data sets, an image.

Nyquist ghost artifacts in echo planar imaging (EPI) are mitigated, reduced, or otherwise eliminated by implementing robust Nyquist ghost correction (NGC) directly from two reversed readout EPI acquisitions. As one advantage, these techniques do not require explicit reference scanning. A model-based process is used for directly estimating statistically optimal NGC coefficients from multi-channel k-space data.

A magnetic resonance imaging system and method, and a computer-readable storage medium are provided. The magnetic resonance imaging method includes: acquiring a plurality of k-space data sets by using a plurality of imaging sequences, each imaging sequence comprising a pre-phase-dispersion gradient pulse and a plurality of phase encoding gradients applied after the pre-phase-dispersion gradient pulse, wherein the pre-phase-dispersion gradient pulses of the plurality of imaging sequences have a standard area difference therebetween when ordered according to area values; respectively reconstructing magnetic resonance images from the respective k-space data sets; and averaging amplitudes of the magnetic resonance images to generate a magnetic resonance image of an average amplitude.