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.

A method for producing an image of a subject using a magnetic resonance imaging (MRI) system includes acquiring a series of echo signals by sampling k-space along radial lines that each pass through the center of k-space. Each projection of the radial lines is divided into multiple echoes and successive projections are spaced by a predetermined angular distance. The series of echo signals are reconstructed into a plurality of images, wherein each image corresponds to a distinct echo signal.

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.

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.

Embodiments relate to a method and system to improve fat suppression and reduce motion and off-resonance artifacts in magnetic resonance imaging (MRI) by using a background-suppressed, reduced field-of-view (FOV) radial imaging. The reduction of such artifacts provides improved diagnostic image quality, higher throughput of MRI scans for the imaging center, and increased patient comfort. By using a small FOV radial acquisition that only encompasses the structures of interest, structures that cause motion artifacts, such as the anterior abdominal wall, bowel loops, or blood vessels with pulsatile flow, are excluded from the image. According to an embodiment, combining a small FOV radial acquisition with one or more background-suppression techniques minimizes the impact of artifacts caused by anatomy outside of the FOV.

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.

In a method for generating at least one MR image of an object in an MR system comprising a plurality of signal receiving coils, a sequence of RF pulses are applied in order to generate a plurality of MR signal echoes, the MR signal-echoes are detected with the plurality of signal receiving coils in a 3-dimension-al k-space, and the at least one MR image is reconstructed using the non-homogeneous under sampled 3-dimensional k-space based on a compressed sensing technology. The 3-dimensional k-space may be undersampled with a plurality of constant radii corkscrew trajectories having different radii resulting in a non-homogeneous undersampled 3-dimensional k-space.

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 one embodiment, an MRI apparatus includes a scanner and processing circuitry. The scanner includes at least two gradient coils. The processing circuitry is configured to cause the scanner to acquire k-space data for correction in a band-shaped two-dimensional k-space along a readout direction, or in a columnar three-dimensional k-space along a readout direction, while changing rotation angles, wherein each of the rotation angles corresponds to the readout direction, generate correction data for correcting an error due to a gradient magnetic field generated by the gradient coils, by using the acquired k-space data for correction, cause the scanner to acquire k-space data for reconstruction, based on a radial acquisition method, while correcting the gradient magnetic field by using the correction data, and generate an image by reconstructing the acquired k-space data for reconstruction.

A magnetic resonance imaging (MRI) system and method for acquiring magnetic resonance (MR) images using a pulse sequence implementing driven equilibrium and quadratic phase cycling techniques is provided. The method includes, during a pulse repetition period of a pulse sequence and using a quadratic phase cycling scheme, applying a first RF pulse to deflect a net magnetization vector associated with the subject from a longitudinal plane into a transverse plane; after applying the first RF pulse, applying a first sequence of RF pulses each of which flips the net magnetization vector by approximately 180 degrees within the transverse plane; and after applying the first sequence of RF pulses, applying a second RF pulse to deflect the net magnetization vector from the transverse plane to the longitudinal plane.