A system and method is provided for producing a map of a static magnetic field (B.sub.0) of a magnetic resonance imaging system. The method includes forming a first dataset by acquiring, with the MRI system, a first plurality of different echo signals occurring at a respective plurality of different echo times. The method also includes forming a second dataset by acquiring, with the MRI system, a second plurality of different echo signals occurring at a respective plurality of different echo times. The second dataset includes signals resulting from a magnetization transfer (MT) between free water and bound molecules. The method further includes generating MT-weighted maps using the first dataset and the second dataset, determining, using the MT-weighted maps, a phase difference between the first plurality of different echo signals, and using the phase differences, generate a corrected map of the static magnetic field (B.sub.0) of the MRI system.

Disclosed herein is a method for generating an MRI image in which a radial or spiral k-chamber path with a constant angular increment Psi is used to take an MRI image, the angular increment Psi being in the angular range of between 5-55 degrees or being in the corresponding supplementary angle Psi′ and is selected according to the formula Psi.sub.N,M=pi/(N+1/(M+tau−1)). Alternatively, for an angular increment Psi which deviates from the angle increment of the optimal distribution of n radial profiles Psi.sub.opt=180°/n, the minimum scanning efficiency of the angular increment Psi for n>21 profiles is greater than 0.95, the angular increment Psi is in an angular range of 5° to less than 68.7537°, in particular between 5-55 degrees or in the corresponding supplementary angle Psi′. Compared to the arrangement of the radial or spiral profile using the golden angle of 111.24°, the angle increments calculated according to the above formula lead to lower eddy current artifacts, for example during the use of a b-SSFP-pulse sequence.

Described herein are systems and methods for the selective mapping of water T1 relaxation times.

A method of acquiring image data with an MRI system from an object using a sequence of tip-down and tip-up RF pulses is described. A slice-selective first pulse α rotates the in-slice spins from the longitudinal axis (z) toward a transverse plane (x, y). Image data is acquired from the in-slice spins during a free precession interval (T.sub.free) in which the in-slice spins precess along the transverse plane (x, y). A spatially tailored, non-slice-selective second pulse β({right arrow over (r)}) is applied for rotating the in-slice spins from the transverse plane (x, y) to at least substantially along the longitudinal axis (z). A third pulse S may be applied to the in-slice and out-of-slice spins to eliminate (spoil) residual transverse signal from out-of-slice spins.

A method and system for imaging a body using a magnetic resonance imaging (MRI) apparatus, including motion tracking of a target object of the body using MRI by generating an MRI image of a region of interest of the body by performing a weighted combination of a signal received by each coil of an MRI apparatus during an MRI scan.

Some aspects of the present disclosure relate to systems and methods for magnetic resonance thermometry. In one embodiment, a preliminary balanced steady state free precession (bSSFP) magnetic resonance imaging pulse sequence is applied to an area of interest of a subject. Based on bSSFP image phases, a relationship between frequency and image phase associated with the area of interest can be determined and a bSSFP magnetic resonance imaging pulse sequence applied for temperature change measurement during and/or after focused energy is applied to the subject. Based on image phase change associated with temperature change and using the determined relationship between frequency and image phase, a change in the resonance frequency associated with the target area due to the application of the focused energy can be determined, and the temperature change can be determined based on the determined change in the resonance frequency.

Methods and systems for performing T1 mapping. T1 samples are obtained from an acquisition including one or more inversion groupings. The acquisition may be designed to result in incomplete tissue magnetization recovery between inversion groupings. The acquisition may be designed for the use of non-uniform, non-180° preparatory pulses. The method may also include the combined use of data from different inversion groupings. A model is used in which fit parameters are variable dependent on the inversion grouping.

Embodiments relate to acquiring magnetic resonance (MR) images with suppressed residual blood signal in the early cardiac phases, leading to images with a preferred dark-blood appearance throughout the entire cardiac cycle, which improves accuracy of subsequent post-processing algorithms. The acquisition of the desired blood suppressed tissue images is achieved through a double inversion recovery pulse in DENSE sequences. The double inversion recovery pulse is applied after an electrocardiogram (ECG) trigger at a beginning point of a repetition time period, followed by a displacement encoding module at an inversion time during the repetition time period and a readout module comprised of a plurality of frames during a remainder of the repetition time period. The displacement encoding module applies a labelling process on the tissue, while the readout module applies an un-labelling process. The readout module comprises an imaging sequence adapted to acquire DENSE images.

In a method and apparatus for acquiring magnetic resonance (MR) data from a predetermined volume within an examination object, a control protocol for a gradient echo sequence is selected that specifies that gradient moments produced in said gradient echo sequence be balanced along all three spatial directions. In this gradient echo sequence a slice selection gradient is activated in a slice selection direction that produces a balanced gradient moment, with simultaneous radiation of an RF pulse that simultaneously excites nuclear spins in multiple slices of the examination object, with said excitation being repeated according to a repetition time. A phase of MR signals to be acquired from a same one of said multiple layers is varied from repetition time-to-repetition time. An additional gradient is activated in the slice selection gradient that produces an additional gradient moment that is constant over consecutive repetition times and thus overrides the condition of the gradient moments of the gradient echo sequence being balanced along said slice selection direction. The MR signals are acquired during activation of a readout gradient.

In a method of performing magnetic resonance (MR) imaging, an MR apparatus, and a computer-readable medium during a first cardiac cycle of a subject, a first imaging sequence is generated for application to a subject. The first imaging sequence has a preparatory pulse and an inversion recovery pulse following the preparatory pulse. First signals emitted from the subject in response to the first imaging sequence are detected, and first image data are generated based on the first signals. During a second cardiac cycle following the first cardiac cycle, a second imaging sequence is generated for application to the subject. The second imaging sequence has a preparatory pulse. Second signals emitted from the subject in response to the second imaging sequence are detected, and second image data are generated based on the second signals.