The present disclosure is directed to systems and methods for generating images using short tau inversion recovery, ultrashort echo time (STIR-UTE) MRI sequences. The STIR-UTE MRI sequences can be used to generate images that can differentiate between regions that are at temperatures that are either lethal or non-lethal to cell life. Thus, these sequences can be beneficial for implementations such as in monitoring cryoablation procedures.

A method includes acquiring initial scout images of a patient's heart, using a neural network to establish a patient specific heart model, and automatically plan imaging planes of the patient specific heart model, performing an accelerated scan of the patient's heart, using the neural network to determine a current location and pose of the patient's heart from the accelerated scan, and to reposition the imaging planes to correspond to the current location and pose of the patient's heart, and using the repositioned imaging planes to perform an acquisition scan and generate an image of the patient's heart from the acquisition scan according to a selected imaging protocol.

A method includes using fully sampled retro cine data to train an algorithm, and applying the trained algorithm to real time MR cine data to yield reconstructed MR images.

The invention relates to a method of MR imaging of an object. It is an object of the invention to provide a multi-gradient echo imaging technique with increased acquisition speed and intrinsic suppression of artefacts from Bo inhomogeneities, T.sub.2* decay, chemical shift, motion, and/or flow, in particular in combination with radial or spiral k-space trajectories. The method of the invention comprises the steps of: —subjecting the object (10) to an imaging sequence comprising RF excitation pulses and switched magnetic field gradients, wherein multiple echo signals are generated at different echo times after each RF excitation pulse, —acquiring the echo signal data along radial or spiral k-space trajectories, wherefore the imaging sequence comprises magnetic field gradient blips in the x-/y- and/or z-directions; —separating signal contributions from water and fat to the echo signals and estimating a B.sub.0 map and/or an apparent transverse relaxation time map (T.sub.2* map) using a Dixon algorithm; and —synthesizing an image of a specified contrast from the echo signal data, the Bo map and/or the T.sub.2* map. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

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.

The invention relates to a method of MR imaging of an object (10). It is an object of the invention to enable MR imaging using the stack-of-stars or stack-of-spirals acquisition scheme providing an enhanced image quality in the presence of motion. The method of the invention comprises the steps of:—generating MR signals by subjecting the object to an imaging sequence comprising RF pulses and switched magnetic field gradients;—acquiring signal data according to a stack-of-stars or stack-of-spirals scheme, wherein the MR signals are acquired as radial or spiral k-space profiles from a number of parallel slices arranged at adjacent positions along a slice direction, wherein a central portion (20) of k-space is more densely sampled during the acquisition than peripheral portions (21) of k-space;—reconstructing an intermediate MR image (22-25) from sub-sampled signal data for each of a number of successive time intervals;—deriving motion induced displacements and/or deformations by registering the intermediate MR images (22-25) with each other; and—combining the sub-sampled signal data and reconstructing a final MR image therefrom, wherein a motion correction is applied according to the derived motion induced displacements and/or deformations. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).

The invention relates to a method of Dixon-type MR imaging. It is an object of the invention to provide a method that enables efficient and reliable water/fat separation using bipolar readout magnetic field gradients and avoids flow-induced leaking and swapping artifacts. According to the invention, an object (10) is subjected to an imaging sequence, which comprises at least one excitation RF pulse and switched magnetic field gradients, wherein two echo signals, a first echo signal and a second echo signal, are generated at different echo times (TE1, TE2). The echo signals are acquired from the object (10) using bipolar readout magnetic field gradients. A first single echo image is reconstructed from the first echo signals and a second single echo image is reconstructed from the second echo signals. A zero echo time image is computed by extrapolating the phase of the first single echo image at each voxel position to a zero echo time using the phase difference between the first and the second single echo image at the respective voxel position. Flow-induced phase errors are identified and estimated in the zero echo time image, and the phase of the first single echo image is corrected according to the estimated flow-induced phase errors. Finally, a water image and/or a fat image are reconstructed from the echo signals, wherein signal contributions from water and fat to the echo signals are separated using the phase-corrected first single echo image and the second single echo image. Moreover, the invention relates to a MR device (1) and to a computer program to be run on a MR device (1).

A method and system for determining a magnetic field map in a MR system based on position of a movable patient support of the MR system are provided, wherein a first resulting field map including position dependent information about a magnetic field distribution in a homogeneity volume including an examination volume of the MR system is provided when the movable patient support is located at a first position, wherein a stationary field map including information about a magnetic field distribution in the homogeneity volume is provided, which is independent of the position of the movable patient support, wherein a position dependent field map including information about a magnetic field distribution in the homogeneity volume mainly influenced by a position of the movable patient support is determined using the stationary field map and the first resulting field map, and wherein a second resulting field map in the homogeneity volume is determined when the movable patient support is located at a second position different from the first position, using the stationary field map and the position dependent field map.

In a computer-implemented method of training a machine learning based processor, the processor can be trained to derive image data from signal data sets of multiple spin echo sequences. The trained processor can be configured to perform image processing for Magnetic Resonance Imaging (MRI) to derive the image 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.