In a magnetic resonance method and apparatus for determining a characteristic of an organ, a magnetic resonance sequence is executed in order to acquire temporally resolved magnetic resonance data pertaining to the organ. The magnetic resonance sequence includes at least one tagging module, which generates a sub-visual tag of the magnetic resonance data. The characteristic of the organ is determined in a processor using the sub-visual tag.

In a method and apparatus for generating a magnetic resonance data record, at least two excitation cycles are executed, wherein, in each excitation cycle, at least one magnetic resonance signal is recorded, using different phases with a first radio-frequency pulse in two consecutive excitation cycles, with at least one dephasing gradient being applied in an excitation cycle.

A tissue type fraction within a biological object is determined by a phase-cycled acquisition of several images of the object and deriving a complex signal profile for each voxel of the acquired images; generating a multidimensional dictionary of simulated signal profiles, wherein each simulated signal profile is configured for simulating the previously derived complex signal profile; using a weight optimization algorithm configured for expressing the complex signal profile as a weighted sum of the simulated signal profiles, wherein the weight optimization algorithm provides as output for each voxel a matrix M of optimized weights; for each voxel and each dimension of the obtained matrix M, extracting from the matrix M a distribution of the obtained optimized weights; and determining a type of tissue composing each voxel from the obtained distributions.

In a method for controlling a magnetic resonance imaging system as part of functional magnetic resonance imaging, a main magnetic field B0 is provided having a field strength of at most 1.4 tesla at a main field magnet system (4) of the magnetic resonance imaging system (1); and a measurement is performed as part of functional magnetic resonance imaging, wherein a measurement sequence (MS) is applied that has a longer echo time TE (e.g. longer than 100 ms).

Systems and methods for high-resolution STAGE imaging can include acquisition of relatively low-resolution k-space datasets with two separate multi-echo GRE sequences. The multi-echo GRE sequences can correspond to separate and distinct flip angles. Various techniques for combining the low-resolution k-space datasets to generate a relatively high-resolution k-space are described. These techniques can involve combining low-resolution k-space datasets associated with various echo types. The STAGE imaging approaches described herein allow for rapid imaging, enhanced image resolution with relatively small or no increase in MR data acquisition time.

In a method and apparatus for recording a magnetic resonance dataset with a number of reception coils, wherein the measurement signals of the magnetic resonance dataset contain measurement signals from at least two slices, the measurement signals are recorded segmented by the measurement signals being recorded in a first area of k-space with a first scanning density and in a second area of k-space with a second scanning density.

A magnetic resonance imaging apparatus according to the present embodiment includes processing circuitry and imaging control circuitry. The processing circuitry selects a human body model corresponding to a subject from human body models. The processing circuitry estimates local specific absorption rates (SARs) at evaluation points determined using the selected human body model, based on the selected human body model and an amplitude and/or phase of the RF pulse in an imaging protocol for magnetic resonance imaging scheduled to be performed on the subject. The processing circuitry determines whether or not the estimated local SARs fall below a local reference value. The imaging control circuitry executes the imaging protocol by using an amplitude and phase of the RF pulse which make the local SARs fall below the local reference value.

A method of MR imaging of a body (10) of a patient reduces contrast blurring in PROPELLER imaging combined with multi-echo acquisitions. The method includes the steps of: generating MR signals by subjecting at least a portion of the body (10) to a MR imaging sequence including a number of RF pulses and switched magnetic field gradients; acquiring the MR signals as a plurality of k-space blades (21-26) in temporal succession according to a PROPELLER scheme, each k-space blade (21-26) including a number of substantially parallel k-space lines, wherein the k-space blades (21-26) are rotated about the center of k-space, so that a total acquired data set of MR signals spans at least part of a circle in k-space, wherein a common central circular region of k-space is covered by all k-space blades (21-26), wherein a relaxation weighting of the MR signals varies between different k-space blades (21-26); estimating the relaxation weighting of the MR signals; compensating the acquired MR signals according to the estimated relaxation weighting; and reconstructing a MR image from the compensated MR signals.

A method for generating magnetic resonance images of a subject includes performing, using a magnetic resonance imaging (MRI) system, an interrupted three-dimensional (3D) single shot unbalanced steady-state free precession (uSSFP) pulse sequence to acquire MR data for each of a plurality of partitions associated with a region of interest of a subject. The interrupted 3D single shot uSSFP pulse sequence may be configured to suppress blood signal in the region of interest. The MR data for each partition is acquired as a single shot along an in-plane phase-encoding direction and the acquisition of MR data for each partition is synchronized to a phase of a cardiac cycle. The method further includes generating, using a processor, an image with blood suppression based on the acquired MR data.

Methods and apparatus for operating a low-field magnetic resonance imaging (MRI) system to perform diffusion weighted imaging, the low-field MRI system including a plurality of magnetics components including a B.sub.0 magnet configured to produce a low-field main magnetic field B.sub.0, at least one gradient coil configured to, when operated, provide spatial encoding of emitted magnetic resonance signals, and at least one radio frequency (RF) component configured to acquire, when operated, the emitted magnetic resonance signals. The method comprises controlling one or more of the plurality of magnetics components in accordance with at least one pulse sequence having a diffusion-weighted gradient encoding period followed by multiple echo periods during which magnetic resonance signals are produced and detected, wherein at least two of the multiple echo periods correspond to respective encoded echoes having an opposite gradient polarity.