The present invention relates to a method for side-band suppression in a Magnetic Resonance imaging, MRI, system (100), the method comprising providing a first multiband RF pulse for simultaneously exciting at least two slices in a subject (118) at a first and a second frequency band (301,303) and to acquire using the MRI system (100) signals (307, 308) from the excited two slices and at least one additional signal (309) at a third frequency band (305), the additional signal (309) resulting from a sideband excitation of a slice different from the two slices; using the first multiband RF pulse for determining the additional signal (309); deriving a pre-compensating term from the first multiband RF pulse and the additional signal (309), adding the pre-compensating term to the first multiband RF pulse to obtain a second multiband RF pulse, thereby replacing the first multiband RF pulse by the second multiband RF pulse for suppressing at least part of the additional signal (309).

The invention relates to a method of MR imaging of an object positioned in an examination volume of a MR device (1). It is an object of the invention to enable efficient silent ZTE imaging with self-refocusing. The method of the invention comprises the steps of:—specification of a set of radial k-space spokes to cover a spherical k-space volume;—selection of subsets of a predetermined number of spokes from the specified set so that the concatenation of the spokes contained in each of the subsets forms a closed trajectory in k-space, wherein the selection of the subsets involves optimizing a cost function;—subjecting the object (10) to a zero echo time imaging sequence, wherein each of the subsets of spokes is acquired as a sequence of gradient echo signals; and—reconstructing an MR image from the acquired spokes. Moreover, the invention relates to a MR device and to a computer program for a MR device.

A magnetic resonance imaging method executed in a magnetic resonance imaging apparatus according to an embodiment comprises: applying an inversion pulse; executing a subsequent imaging sequence including an RF (Radio Frequency) pulse and a gradient magnetic field concurrently applied with the RF pulse in a slice direction and performing, for a slice position selected by the RF pulse and the gradient magnetic field and during a time period including a null point, data acquisition in a plurality of orientations including a center of a two-dimensional k-space.

A gradient system for a magnetic resonance imaging system can include at least two examination areas using a common basic magnetic field and a number of gradient coils in the at least two examination areas, and a gradient controller configured such that it controls the electric current flowing through at least two gradient coils for similar gradient axes in different examination areas in a temporal synchronous manner.

In one aspect, in accordance with one embodiment, a method includes acquiring magnetic resonance (MR) data corresponding to bone tissue in an area of interest of a subject that is heated from the application of localized energy. The acquiring includes applying a three-dimensional (3D) ultra-short echo time (UTE) spiral acquisition sequence. The method also includes detecting, from the acquired magnetic resonance data, a change in MR response signal due to a change in at least one of relaxation rate and magnetization density caused by heating of the bone tissue; and determining, based at least in part on the change in the MR response signal, that the temperature of the bone tissue has changed.

The invention relates to a method of MR imaging of an object positioned in an examination volume of a MR device (1). It is an object of the invention to enable ‘silent’ ZTE imaging with improved sampling of k-space center. According to the invention, the object (10) is subjected to an imaging sequence of RF pulses (20) and switched magnetic field gradients, which imaging sequence is a zero echo time sequence comprising: i) setting a readout magnetic field gradient having a readout direction and a readout strength (G1, G2); ii) radiating a RF pulse (20) in the presence of the readout magnetic field gradient; iii) acquiring a FID signal in the presence of the readout magnetic field gradient, wherein the FID signal represents a radial k-space sample (31, 32), wherein the acquisition of the FID signal is started at an acquisition time at which a receiver gain of the MR device (1) has not yet stabilized after the radiation of the RF pulse (20); iv) incrementally varying the readout direction; v) sampling a spherical volume in k-space by repeating steps i) through iv) a number of times. Finally, a MR image is reconstructed from the acquired FID signals. Moreover, the invention relates to a MR device and to a computer program for a MR device.

A magnetic resonance imaging apparatus according to an embodiment includes processing circuitry. The processing circuitry acquires an echo signal generated for each of intervals of repetition time by applying an excitation pulse to a subject at the intervals of repetition time, and acquires data of a plurality of trajectories set for a k-space using the echo signals. The processing circuitry acquires a plurality of echo signals by setting echo time to lengths different between a plurality of periods of repetition time and acquires data of the same trajectory using the echo signals, and the echo time serves as time from application of the excitation pulse to generation of the echo signal.

Devices, systems and methods for imaging cortical and trabecular bone are described. An example method for imaging cortical and trabecular bone is provided to include applying one or more adiabatic inversion recoveiy pulses to a cortical and trabecular bone, wherein the one or more adiabatic inversion recoveiy pulses are provided with multiple spokes in a three dimensional adiabatic ultrashort TE cones sequence (3D UTE-Cones sequence) that has a TR/TI combination, TR and TI corresponding to repetition time and inversion time, respectively; and performing data acquisition, by using the multiple spokes, on a target signal obtained after the applying of the one or more adiabatic inversion recoveiy pulses.

A method of magnetic resonance (MR) imaging to enable ‘silent’ zero echo time (ZTE) imaging in combination with water/fat separation. The method includes subjecting the object to a first self-refocusing zero echo time imaging sequence, wherein a first sequence of gradient echo signals is acquired as a first number N.sub.1 of radial k-space spokes at a first repetition time TR.sub.1; subjecting the object to a second self-refocusing zero echo time imaging sequence, wherein a second sequence of gradient echo signals is acquired as a second number N.sub.2 of radial k-space spokes at a second repetition time TR.sub.2, wherein N.sub.2≠N.sub.1 and/or TR.sub.2≠TR.sub.1; and reconstructing a MR image from the acquired gradient echo signals. Signal contributions of chemical species (e.g., water and fat) may be separated exploiting the different echo times attributed to the gradient echo signals.

The present disclosure discloses a method for measuring relaxation time of ultrashort echo time magnetic resonance fingerprinting. In the method, semi-pulse excitation and semi-projection readout are adopted to shorten echo time (TE) to achieve acquisition of an ultrashort T2 time signal; and image acquisition and reconstruction are based on magnetic resonance fingerprint imaging technology. A TE change mode of sinusoidal fluctuation is introduced, so that distinguishing capability of a magnetic resonance fingerprint signal to short T2 and ultrashort T2 tissues is improved, and multi-parameter quantitative imaging of the short T2 and ultrashort T2 tissues and long T2 tissues is realized. Non-uniformity of a magnetic field is modulated into phase information of the fingerprint signal through the TE of the sinusoidal fluctuation; a B0 graph is directly reconstructed according to an amplitude-modulated signal demodulation principle; and the phase change caused by a B0 field is compensated in the fingerprint signal.