In a method and apparatus for acquiring magnetic resonance data of an acquisition region of a patient, in particular at least a part of the head of the patient, navigator data are acquired for motion correction, between diagnostic data acquisition time windows, in navigator time windows by execution of a fat navigator sequence. The fat navigator sequence has a fat-selective excitation module with at least one radio-frequency pulse and a readout module undersampling in a respective navigator slice. Motion data for the motion correction of the diagnostic data are determined from the navigator data. The navigator data are acquired simultaneously from multiple excited fat navigator slices in the fat navigator sequence using simultaneous multislice imaging, after the excitation module acts on a number of fat navigator slices to be acquired in the readout module.

Provided is an apparatus of reconstructing a magnetic resonance (MR) image, the apparatus including: a memory storing instructions; and at least one processor configured to execute the instructions to: obtain a plurality of segments of K-space data corresponding to a plurality of pulses which are applied to an object based on a pulse sequence; determine, based on radio frequency (RF) coils of the apparatus, a correction coefficient for merging the plurality of segments of K-space data; and generate a magnetic resonance (MR) image of the object by merging the plurality of segments of K-space data based on the determined correction coefficient.

Various embodiments of a system and associated method for whole-blade acquisition and phase correction for fast and robust MR imaging are disclosed herein. In particular, the system enables sampling of odd and even k-space echoes in the same k-space as well as a whole-blade phase correction strategy to achieve improved image quality at an accelerated imaging rate.

Distortion generated in an image is effectively corrected in imaging using an EPI sequence such as DWI without extending an imaging time. After one excitation RF pulse of EPI is applied, a navigator scan in which the polarity of the phase encoding is opposite to that of the main scan is performed continuously to the main scan, and the distortion of the image by using the navigator scan data obtained by the navigator scan is corrected. In a case of multi-shot, phase information obtained from the navigator scan data for each shot is used to perform phase correction and multi-shot reconstruction on the main scan data of each shot.

Methods, devices, systems and apparatus for magnetic resonance imaging are provided. In an example, a method includes: obtaining M imaging data sets collected by a receiving coil array including N coil channels under M radio-frequency excitations, determining odd echo phase information and even echo phase information for each of the imaging data sets, mapping M odd echo data sets and M even echo data sets of the imaging data sets as a virtual imaging data set for a virtual coil array that includes NM2 virtual coil channels, and performing parallel magnetic resonance imaging based on the odd echo phase information and the even echo phase information of each of the imaging data sets, the virtual imaging data set and parallel reconstruction reference data.

A system and computerized method for generating magnetic resonance imaging (MRI) images is provided that includes accessing data acquired from a subject using an MRI system that includes Nyquist ghosts and processing the data using a cost function that exploits a cosine and sine modulation in a ghosted image component of the data. An image of the subject is produced from the data after processing the data using the cost function.

A method and imaging system is provided that can control a magnetic gradient system and an RF system of an MRI system according to a calibration pulse sequence to acquire positive readout gradient (RO+) data and negative readout gradient (RO) data. The RO+ data and the RQ data are assembled to form complete image data sets for the RO+ data and the RQ data and the RO+ data and the RO data are combined to generate the calibration data that is ghost-corrected, substantially free of ghost artifacts, or having reduced ghost artifacts compared to traditionally-acquired calibration data. Reconstruction coefficients are derived from the calibration data. The magnetic gradient system and the RF system are controlled according to an imaging pulse sequence to acquire image data and the image data is reconstructed into an image of the subject using the reconstruction coefficients.

A magnetic resonance imaging (MRI) apparatus for obtaining a magnetic resonance (MR) image using a multi-echo pulse sequence including a plurality of repetition times, including a memory configured to store an MR signal obtained using the multi-echo pulse sequence, and an image processor configured to determine a plurality of echo times included in the plurality of repetition times to provide the multi-echo pulse sequence including the plurality of echo times during the plurality of repetition times, and to obtain the MR image, based on the MR signal, wherein the plurality of repetition times includes a first repetition time adjacent to a second repetition time, wherein the plurality of echo times includes a first echo time of the first repetition time, a second echo time of the first repetition time, a first echo time of the second repetition time, and a second echo time of the second repetition time.

Various methods and systems are provided for ghost artifact reduction in magnetic resonance imaging (MRI). In one embodiment, a method for an MRI system comprises acquiring a non-phase-encoded reference dataset, calculating phase corrections for spatial orders higher than first order from the non-phase-encoded reference dataset, acquiring a phase-encoded k-space dataset, correcting the phase-encoded k-space dataset with the phase corrections, and reconstructing an image from the corrected phase-encoded k-space dataset. In this way, ghost artifacts caused by phase errors during EPI may be substantially reduced, thereby improving image quality especially when imaging with a large field of view.

Variable flip angle techniques with constraints for reconstructing MR images include a processor generating a T.sub.1app map representing a spatial distribution of T.sub.1app within an anatomical region using a first MR dataset corresponding to a first flip angle (FA) and a second MR dataset corresponding to a second FA. The processor can estimate a first and second transmit RF field maps by scaling the T.sub.1app map by a first constant value of T.sub.1 associated with a first tissue type and a second constant value of T.sub.1 associated with a second tissue type, respectively. The processor can generate a third transmit RF field map using the first and second transmit RF field maps, and use the third transmit RF field map to construct MR images of the anatomical region. Weighted subtraction images can be created with improved contrast-to-noise ratio compared to images of the first and second MR datasets.