A method for correcting a B0 inhomogeneity in a magnetic resonance scan with a magnetic resonance tomograph is provided. The magnetic resonance tomograph includes a controller, a radio frequency unit, and a transmitting antenna. In the method, the controller determines a transmission signal that is suitable for correcting an effect of an inhomogeneity of a static B0 magnetic field in an examination volume by the Bloch-Siegert effect. The transmission signal is emitted into the examination volume.

Described here are systems and methods for designing and implementing spatially selective, multidimensional adiabatic radio frequency (RF) pulses for use in magnetic resonance imaging (MRI). Spatially selective inversion can be achieved adiabatically in both two-dimensional (2D) and three-dimensional (3D) regions-of-interest. The multidimensional adiabatic pulses are generally designed using sub-pulses that are adiabatically driven using a parent adiabatic pulse.

A method for controlling a magnetic resonance system outputs a pulse sequence including a first slice-selective excitation pulse that excites a first slice with a first magnetization. The pulse sequence includes a second slice-selective excitation pulse that excites a second slice with the first magnetization and a third slice-selective excitation pulse that excites the first slice with a second magnetization that cancels the first magnetization. The pulse sequence also includes and a fourth slice-selective excitation pulse that excites the second slice with a magnetization that cancels the first magnetization. The first slice and the second slice intersect.

In a method and magnetic resonance (MR) apparatus for acquiring MR signals from an examination object an RF excitation pulse is directed into the examination object while activating magnetic field gradients in two different spatial directions, such that a magnetization in the examination object in the two different spatial directions is limited by the RF excitation pulse and the switching of the magnetic field gradients. The magnetization is excited in one of the two spatial directions, of a slice selection direction, in a number of periodic layers, so MR signals are generated in the multiple periodic slices. The MR signals in the multiple periodic layers are read out using multiple reception coils of the MR scanner.

A method of designing a refocusing pulse or pulse train for Magnetic Resonance Imaging comprises the steps of: a) determining a phase-free performance criterion representative of a proximity between a rotation of nuclear spins induced by the pulse and a target operator, summed or averaged over one or more voxels of an imaging region of interest; and b) adjusting a plurality of control parameters of the pulse to maximize the phase-free performance criterion; wherein each target operator is chosen so the phase-free performance criterion takes a maximum value when the nuclear spins within all voxels undergo a rotation of a same angle around a rotation axis lying in a plane perpendicular to a magnetization field B.sub.0, called a transverse plane, with an arbitrary orientation; wherein the angle is different from M radians, with integer M, preferably with < radians and even preferably with 0.9.Math. radians.

A magnetic resonance imaging system acquires magnetic resonance data from a target volume in a subject. The magnetic resonance imaging system includes multiple excitation sources for generating a slice-selective or slab-selective spatial radio frequency (RF) excitation magnetic field targeting slice/slab spatial variations in the target volume, and a controller coupled to the excitation sources. The controller is adapted for: determining a power level required by the excitation sources for generating the slice-selective/or slab-selective spatial RF excitation magnetic field, decomposing the slice-selective or slab-selective spatial RF excitation magnetic field into respective RF excitation constituents of the excitation sources, controlling each of the excitation sources to simultaneously generate the respective RF excitation constituent, using the determined power level for acquiring the magnetic resonance data.

A method for magnetic resonance imaging is provided that includes using a magnetic resonance imaging system to excite a field of view (FOV) for a target being imaged, using an excitation plan to limit the excited FOV to a relatively narrow band of magnetization, exciting multiple bands of magnetization simultaneously, applying phase encoding along a shortest FOV dimension, acquiring a signal from said simultaneously excited bands of magnetization, and reconstructing and outputting a target image from the acquired signal.

Methods for fast magnetic resonance imaging (MRI) using a combination of outer volume suppression (OVS) and accelerated imaging, which may include simultaneous multislice (SMS) imaging, data acquisitions amenable to compressed sensing reconstructions, or combinations thereof. The methods described here do not introduce fold-over artifacts that are otherwise common to reduced field-of-view (FOV) techniques.

Described here are systems and methods for volumetric excitation in magnetic resonance imaging (MRI) using frequency modulated radio frequency (RF) pulses. In general, quadratic phase modulation along the slice encoding direction is implemented for additional spatiotemporal encoding, which better distributes signal content in the slice direction and enables higher acceleration rates that are robust to slice-undersampling.

The present disclosure provides technologies that allow reduced field of view or fast imaging with reduced image distortion. The first technique capitalizes on the benefit of reduced field of view imaging for full field of view coverage. The second technique allows achieves high resolution 3D images in a focused region. These techniques are expected to have applications for cancer imaging, neuro imaging, and other biomedical imaging areas.