G01R33/5618

Magnetic resonance imaging apparatus and method for obtaining magnetic resonance image

A magnetic resonance imaging (MRI) apparatus for obtaining a magnetic resonance (MR) image using a multi-echo pulse sequence including a plurality of repetition times, including a memory configured to store an MR signal obtained using the multi-echo pulse sequence, and an image processor configured to determine a plurality of echo times included in the plurality of repetition times to provide the multi-echo pulse sequence including the plurality of echo times during the plurality of repetition times, and to obtain the MR image, based on the MR signal, wherein the plurality of repetition times includes a first repetition time adjacent to a second repetition time, wherein the plurality of echo times includes a first echo time of the first repetition time, a second echo time of the first repetition time, a first echo time of the second repetition time, and a second echo time of the second repetition time.

MRI apparatus and image processing apparatus
10488479 · 2019-11-26 · ·

In one embodiment, an MRI apparatus includes: a scanner equipped with at least a static magnetic field magnet, a gradient coil, and an RF coil configured to apply RF pulses to an object and receive magnetic resonance signals from the object; and processing circuitry configured to set a pulse sequence in which refocusing pulses are sequentially applied subsequent to application of one excitation pulse and a predetermined number of magnetic resonance signals are acquired in each period between adjacent two refocusing pulses by using a water/fat separation method, such that the magnetic resonance signals are different in echo time TE for each of the plurality of refocusing pulses, cause the scanner to acquire the magnetic resonance signals under the pulse sequence, and generate a computed image from the magnetic resonance signals, the computed image being a magnetic resonance image of the object obtained by computation.

Imaging systems and methods

An imaging method may include obtaining imaging data associated with a region of interest (ROI) of an object. The imaging data may correspond to a plurality of time-series images of the ROI. The imaging method may also include determining, based on the imaging data, a data set including a spatial basis and one or more temporal bases. The spatial basis may include spatial information of the imaging data. The one or more temporal bases may include temporal information of the imaging data. The imaging method may also include storing, in a storage medium, the spatial basis and the one or more temporal bases.

MR imaging using multi-echo k-space acquisition

An object to be MR imaged (10) is placed in an examination volume of a MR device (1). For faster MR imaging a multi-echo imaging technique which is robust with respect to motion is used. The method includes generating echo signals by subjecting the object (10) to an imaging sequence, acquiring the echo signals, each echo signal being attributed to a k-space line, wherein a number of k-space lines, which are adjacently arranged in a part of k-space, are repeatedly sampled, with said number of k-space lines being sampled in a different sequential order per repetition, and reconstructing a MR image from the acquired echo signals.

SYSTEMS AND METHODS FOR LOW-FIELD FAST SPIN ECHO IMAGING

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.

Magnetic resonance imaging apparatus and method of obtaining magnetic resonance image by using multiple excitation with delayed spin-echoes
10408907 · 2019-09-10 · ·

A magnetic resonance imaging (MRI) apparatus, including a radio frequency (RF) transmitter configured to transmit a plurality of excitation RF pulses to an object, and to transmit a refocusing RF pulse to the object within a repetition time (TR) period after transmitting the plurality of excitation RF pulses; and a controller configured to control the RF transmitter to transmit a plurality of first additional gradient magnetic fields corresponding to the plurality of excitation RF pulses in order to spoil a plurality of free induction decay (FID) signals produced by the plurality of excitation RF pulses, and to transmit a plurality of second additional gradient magnetic fields corresponding to the plurality of excitation RF pulses in order to generate a plurality of spin echo signals corresponding to the spoiled plurality of FID signals; and an RF receiver configured to acquire the generated plurality of spin echo signals.

Methods and apparatus for bone segmentation in magnetic resonance images

Methods and apparatus for processing magnetic resonance imaging (MRI) data to perform bone segmentation. MRI data comprising a set of gradient-echo images acquired throughout a spin echo is processed to generate a bone segmentation image. The bone segmentation image is generated based, at least in part, on at least two images in the set of gradient-echo images, wherein the at least two images include a first image corresponding to a beginning portion of the spin echo and a second image corresponding to a central portion of the spin echo.

MAGNETIC RESONANCE IMAGING APPARATUS AND CALCULATION IMAGE GENERATION METHOD

A plurality of subject parameter maps are acquired at high speed. In addition to using an imaging sequence for generating both a gradient echo and a spin echo in a single imaging sequence, one or more parameters such as the longitudinal relaxation time T1 and the apparent transverse relaxation time T2* are calculated using the gradient echo and another parameter such as true transverse relaxation time T2 is calculated using the spin echo. When a value of one parameter is calculated, a value of the parameter calculated at the time of calculating the other parameter can be used.

MAGNETIC RESONANCE METHOD AND APPARATUS FOR ARTIFACT PREVENTION IN FAST 3D SPIN ECHO SEQUENCES
20190227139 · 2019-07-25 · ·

In a method and magnetic resonance (MR) apparatus for creating an MR 3D image dataset, spin echo sequences are used to acquire two raw datasets that are each undersampled, wherein the excitation pulses or the refocusing pulses radiated in the data acquisitions have an opposite phase for the two raw datasets. These two raw datasets are combined into a combined 3D raw dataset that is not undersampled, and a weighting matrix is calculated for use in calculating the raw data points that were not acquired in the first raw dataset and the raw data points not acquired in the second raw dataset. A first complete raw dataset and second complete raw dataset are thereby calculated, which are then combined. The MR 3D data is then reconstructed from tis combined raw dataset.

MRI with repeated K-T-sub-sampling and artifact minimization allowing for free breathing abdominal MRI
10317499 · 2019-06-11 · ·

Methods of processing MRI image data to reduce or eliminate motion-related artifacts in MRI images includes: electronically repeatedly acquiring sets of 2D or 3D k-space data of a target region of a subject using at least one MRI pulse sequence; electronically applying a bootstrapping procedure to produce a large number of images from the acquired k-space data; then electronically evaluating the images produced by the bootstrapping procedure; and electronically identifying an image with a minimal motion-related artifact level from the evaluation of the images produced by the bootstrapping procedure.