G01R33/56536

IMAGE PROCESSING DEVICE, IMAGE PROCESSING METHOD, IMAGE PROCESSING PROGRAM, AND MAGNETIC RESONANCE IMAGING DEVICE
20200329994 · 2020-10-22 ·

Magnetic susceptibility is calculated with high accuracy without significant increase of calculation time. Provided is an image processing device comprising an image processor for creating a susceptibility image representing a magnetic susceptibility of at least one tissue of the subject, from an image created on the basis of magnetic resonance signals generated from a subject, wherein the image processor includes an image separator configured to separate from the image, a specific tissue image representing a content of a predetermined specific tissue and a frequency image, an adder-subtractor configured to calculate a post-subtraction frequency image obtained by subtracting from the frequency image, frequency change caused by the specific tissue, and an image converter configured to calculate a specific susceptibility image representing the magnetic susceptibility of the specific tissue on the basis of the specific tissue image, and to calculate a post-subtraction susceptibility image on the basis of the post-subtraction frequency image.

Cross-term spatiotemporal encoding for magnetic resonance imaging

A method for MRI imaging of a subject includes spatially encoding spins in a slice of the subject in orthogonal first and second directions. The encoding includes applying a chirped radiofrequency (RF) pulse concurrently with application of a magnetic field gradient pulse along the first direction. After applying of the RF pulse, a second chirped RF pulse is applied concurrently with application of a second magnetic field gradient pulse, with polarity opposite that of the first gradient pulse. An encoding magnetic field gradient, constant from applying the first RF pulse until the end of applying the second RF pulse, is concurrently applied along the second direction. Following the encoding, a spin signal is measured concurrently with application of a constant readout magnetic field gradient.

System and method for correcting one or more artifacts within a multi-spectral magnetic resonance image

A method for correcting one or more artifacts within a multi-spectral magnetic resonance image is provided. The method includes acquiring a plurality of spectral bins each including a plurality of voxels and corresponding to a different frequency of MR signals emitted by an imaged object. The plurality of voxels of each spectral bin correspond to the frequency of the spectral bin so as to define a spatial coverage of the spectral bin. The method further includes expanding each spectral bin by increasing the spatial coverage of the spectral bin, and generating the multi-spectral magnetic resonance image based at least in part on the expanded spectral bins.

SYSTEM AND METHOD OF PERCEPTIVE QUANTITATIVE MAPPING OF PHYSICAL PROPERTIES

Exemplary methods for quantitative mapping of physical properties, systems and computer-accessible medium can be provided to generate images of tissue magnetic susceptibility, transport parameters and oxygen consumption from magnetic resonance imaging data using the Bayesian inference approach, which minimizes a data fidelity term under a constraint of a structure prior knowledge. The data fidelity term is constructed directly from the magnetic resonance imaging data. The structure prior knowledge can be characterized from known anatomic images using image feature extraction operation or artificial neural network. Thus, according to the exemplary embodiment, system, method and computer-accessible medium can be provided for determining physical properties associated with at least one structure.

Alternating gradients for metal-induced artifacts correction in magnetic resonance imaging

A method for magnetic resonance imaging suppresses off-resonance gradient-induced image artifacts due to metal. The method includes performing by a magnetic resonance imaging (MRI) apparatus two multi-spectral imaging (MSI) acquisitions within a field of view of the MRI apparatus, where the two MSI acquisitions have alternating-sign readout gradients. The two MSI acquisitions are then processed and combined by the MRI apparatus using a weighted image combination to produce a final image.

System and method for Z-shim compensated echo-planar magnetic resonance imaging

A system and method for imaging a subject includes a first imaging pulse sequence having gradient blips along an x-direction and a y-direction to acquire calibration image data from multiple slices. The imaging pulse sequence also includes a plurality of Z-shimming gradient blips coincident in time with the gradient blips along the x- and y-directions and varied within each slice. A plurality of calibration images are reconstructed from the calibration image data and a comparison image is formed by selecting an image from the calibration images corresponding to at least one of the varied Z-shimming gradient blips for each slice to determine a desired value of the Z-shimming gradient blips. The desired values are used to perform a second pulse sequence to acquire clinical image data from the subject. The second pulse sequence is used to acquire clinical images having been compensated for magnetic susceptibility variations within the subject.

Segmentation of quantitative susceptibility mapping magnetic resonance images

The invention provides for a medical imaging system (100, 400) comprising: a memory (112) for storing machine executable instructions and a processor (106) for controlling the medical imaging system. Execution of the machine executable instructions cause the processor to: receive (200) a preliminary segmentation (124) from a preliminary magnetic resonance image (122) of a region of interest (409), wherein the preliminary segmentation comprises preliminary segmentation edges; reconstruct (202) a first QSM image (124) for the region of interest from QSM magnetic resonance data (122), wherein the reconstruction of the QSM image is at least partially performed using a regularization function, wherein the regularization function is dependent upon the preliminary segmentation edges during reconstruction of the first QSM image; calculate (204) a first segmentation (126) by segmenting the first QSM image using a QSM image segmentation algorithm (134), wherein the first segmentation comprises first segmentation edges; and reconstruct (206) a second QSM image (128) for the region of interest from the QSM magnetic resonance data, wherein the reconstruction of the second QSM image is at least partially performed using the regularization function, wherein the regularization function is dependent upon the first segmentation edges.

Magnetic resonance imaging with enhanced bone visualization
10748309 · 2020-08-18 · ·

A system for bone imaging is disclosed. A processing unit is provided for processing an echo MRI dataset. The processing unit is configured to apply a phase ramp to the radial sampling lines of the complex data according to the radial sampling scheme to obtain a bone-enhanced image dataset, wherein a single phase ramp is applied to a radial sampling line of the sampling scheme, which radial sampling line extends on both sides of an origin defined by the echo time, and wherein the phase ramp is based on an equation. A combining unit is provided for combining the MRI dataset with the bone-enhanced image dataset to obtain a background suppressed image dataset.

System and method for localized processing of quantitative susceptibility maps in magnetic resonance imaging

Systems and methods for quantitative susceptibility mapping (QSM) using magnetic resonance imaging (MRf) and a localized processing technique are described. A field-shift map is processed based on localized regions of local field perturbations. These localized field-shift regions are processed using established QSM algorithms, or using direct dipole inversion techniques, to compute regional susceptibility distributions from the localized field shift information. When the localized regions correspond to subvolumes of the field-shift map, local susceptibility maps can be generated and combined to form a composite quantitative susceptibility map. By computing regional susceptibility distributions based on localized field-shift information, residual streaking artifacts in the susceptibility map are constrained to the individual volumes from which they originate, thereby eliminating their propagation through the image.

METHOD FOR RECORDING MAGNETIC RESONANCE DATA, MAGNETIC RESONANCE FACILITY, COMPUTER PROGRAM AND ELECTRONICALLY READABLE DATA CARRIER
20200249303 · 2020-08-06 · ·

Techniques are disclosed for recording magnetic resonance data with a magnetic resonance facility, wherein a three-dimensional echo-planar imaging sequence is used whereby following a single excitation period (e.g. module) in an echo train, an echo count of k-space rows is read out in a read-out direction in the k-space, and interchanging takes place between these rows by means of gradient pulses of the two phase encoding directions.