A method and system for improving the quality of MR images acquired with optimal variable flip angles includes receiving MRI parameters for a target tissue, selecting at least one objective function from a plurality of objective functions, simulating a relationship between each flip angle and the at least one objective functions based on the MRI parameters, determining optimal variable flip angle distribution to reach optimization of the at least one objective function for whole acquisition of the MR image, selecting or optimizing a k-space strategy, applying a plurality of radio frequency (RF) pulses with the optimal variable flip angle distribution and the k-space strategy to a target area in an object, receiving MR signals from the target area, the MR signals corresponding to the plurality of RF pulses, acquiring, in the k-space strategy, k-space lines based on the MR signals, and reconstructing the MR image from the k-space lines.

A method is provided that includes applying at least one radiofrequency saturation pulse at a frequency or a range of frequencies to substantially saturate magnetization corresponding to an exchangeable proton in the ROI to generate magnetic resonance (MR) data. The MR data is then acquired using an echo-planar imaging readout, which is configured to sample a series of gradient echo pulse trains at a series of gradient echo times and a series of spin echo pulse trains at a series of spin echo times. One or more relaxometry measurement is then computed using the MR data sampled at the gradient echo times and the spin echo times. An oxygen-weighted image is then generated using the one or more relaxometry measurement, and a pH-weighted image is generated using MR data sampled at one or more of the spin echo times or gradient echo times.

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.

It is proposed a method for post-processing images of an region of interest in a subject, the images being acquired with a magnetic resonance imaging technique, the method for post-processing comprising at least the step of: unwrapping the phase of each image, extracting a complex signal over echo time for at least one pixel of the unwrapped images, and calculating fat characterization parameters by using a fitting technique applied on a model, the model being a function which associates to a plurality of parameters each extracted complex signal, the plurality of parameters comprising at least two fat characterization parameters, the magnitude error and the phase error generated by the use of the bipolar readout gradients, the fitting technique being a non-linear least-square fitting technique using pseudo-random initial conditions.

In a method and magnetic resonance (MR) apparatus for creating an MR 3D image dataset, spin echo sequences are used to acquire two raw datasets that are each undersampled, wherein the excitation pulses or the refocusing pulses radiated in the data acquisitions have an opposite phase for the two raw datasets. These two raw datasets are combined into a combined 3D raw dataset that is not undersampled, and a weighting matrix is calculated for use in calculating the raw data points that were not acquired in the first raw dataset and the raw data points not acquired in the second raw dataset. A first complete raw dataset and second complete raw dataset are thereby calculated, which are then combined. The MR 3D data is then reconstructed from tis combined raw dataset.

In a method and system, a reference dataset is recorded using a reference scan based on a GRE or RA RT sequence. A correction dataset is also recorded using a phase correction scan based on a non-phase-encoding EPI sequence. A measurement dataset is recorded using an SMS sequence. Slice-specific GRAPPA kernels are determined from the reference dataset and magnetic resonance images are created by a slice GRAPPA method. Data of the measurement dataset belonging to different slices is separated from one another using the slice-specific GRAPPA kernels and N/2 ghost artifacts are corrected using the correction dataset.

In a method and magnetic resonance tomography apparatus for diffusion imaging, coherences are determined in a processor, which would occur during the diffusion imaging measurement, and an implicit spoil moment M.sub.A resulting from a diffusion gradient pulse is determined in the processor. A spoiler moment M.sub.S is established in the processor as a function of a comparison value and threshold value formed from the implicit spoil moment M.sub.A and the suppression moment M. Depending on whether this comparison value lies below or above the threshold value, different calculation techniques are applied for the spoiler moment M.sub.S. Diffusion gradient pulses and spoiler gradient pulses in accordance with the moments M.sub.A and M.sub.S in a pulse sequence for operating the magnetic resonance tomography apparatus.

The invention relates to a method of MR imaging of an object (10). It is an object of the invention to enable MR imaging using radial acquisition with a reduced level of phase distortions and corresponding image artefacts. The method of the invention comprises the steps of: a) generating MR signals by subjecting the object to an imaging sequence comprising RF pulses and switched magnetic field gradients; b) acquiring the MR signals as radial k-space profiles, wherein pairs of spatially adjacent k-space profiles are acquired in opposite directions and wherein k-space profiles acquired in temporal proximity are close to each other in k-space; c) reconstructing an MR image from the acquired MR signals. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

A system for MRI is provided. The system may obtain a plurality of sets of under-sampled k-space data corresponding to a plurality of frames. Each set of under-sampled k-space data may be acquired simultaneously from a plurality of slice locations of a subject in one of the frames using an MRI scanner. The system may reconstruct a plurality of reference slice images based on the sets of under-sampled k-space data of the plurality of frames. Each of the reference slice images may be representative of one of the slice locations in more than one frame of the frames. The system may further reconstruct a plurality of image series based on the sets of under-sampled k-space data and the reference slice images. Each image series may correspond to one of the slice locations and include a plurality of slice images of the corresponding slice location in the plurality of frames.

Systems and methods for magnetic resonance imaging (MRI) that address the geometric distortions and blurring common to conventional echo planar imaging (EPI) sequences, and that provide new temporal signal evolution information across the EPI readout, are described. Echo planar time-resolved imaging (EPTI) schemes are described to implement an accelerated sampling of a hybrid space spanned by the phase encoding dimension and the temporal dimension. In general, each EPTI shot covers a segment of this hybrid space using a zigzag trajectory with an interleaved acceleration in the phase-encoding direction. The hybrid space may be undersampled and a tilted reconstruction kernel used to synthesize additional data samples.