92 results about "Inversion recovery" patented technology

Systems and methods are described for phase-sensitive magnetic resonance imaging using an efficient and robust phase correction algorithm. A method includes obtaining a plurality of MRI data signals, such as two-point Dixon data, one-point Dixon data, or inversion recovery prepared data. The method further includes implementing a phase-correction algorithm, that may use phase gradients between the neighboring pixels of an image. At each step of the region growing, the method uses both the amplitude and phase of pixels surrounding a seed pixel to determine the correct orientation of the signal for the seed pixel. The method also includes using correlative information between images from different coils to ensure coil-to-coil consistency, and using correlative information between two neighboring slices to ensure slice-to-slice consistency. A system includes a MRI scanner to obtain the data signals, a controller to reconstruct the images from the data signals and implement the phase-correction algorithm, and an output device to display phase sensitive MR images such as fat-only images and/or water-only images.

It is an adaptive optics system based on the linear phase inversion recovery technique, comprising the imaging sensor, the linear phase inversion recovery algorithm, the real-time control algorithm, the wave-front correction and drive circuit, and the reference light source. During the system running, the imaging sensor measures the residual aberration far-field image after the compensation of the wave-front correction device, and subtracting with the benchmark image to obtain the image difference vector. In advance, using the reference light source to calibrate the imaging sensor to obtain the benchmark image, and according to the corresponding relations between the wave-front correction device and the imaging sensor, obtaining the recovery matrix between the image difference vector and control voltage. Multiply the image difference vector and the recovery matrix to obtain the corresponding control voltage of the residual wave-front, and use real-time control algorithms, such as proportional integral, to obtain the control voltage of the wave-front correction device, making the wave-front aberration to be corrected. Compared the adaptive optics system based on the linear phase inversion recovery technique and the conventional adaptive optical technology, it has simple structure, high optical energy efficiency, and other advantages.

Systems and methods are described for chemical shift magnetic resonance imaging in the presence of multiple chemical species. A method includes obtaining a plurality of MRI data signals using a Dixon technique in combination with partially parallel imaging techniques and/or inversion recovery techniques, and processing the plurality of MRI data signals using a Dixon reconstruction technique to create a chemical specific shift image. An apparatus includes a MRI scanner for obtaining images, a controller configured to provide input to the scanner to acquire images using a Dixon technique in combination with partially parallel imaging techniques and/or inversion recovery techniques to produce a plurality of MRI data signals, and processing the plurality of MRI data signals using a Dixon reconstruction technique to create a chemical specific shift image, and an output device to display the resulting image.

DIR imaging of blood vessels by administering a series of DIR preparation pulse modules at a repetition interval short enough that at least two DIR preparation pulse modules generally occur within each RR interval, and by acquiring image data for a plurality of slices following each DIR module.

A system provides B1- and B0-insensitive, blood flow and motion-robust T2-preparation and T2-preparation combined with inversion recovery. An MR imaging system discriminates between imaged tissue types based on transverse relaxation time (T2) or transverse relaxation time combined with longitudinal recovery time (T1). A signal generator generates a pulse sequence for T2 preparation or combined T2-preparation with inversion recovery comprising one or more B1 independent refocusing (BIREF-1) pulses for refocusing of magnetization of an anatomical region of interest being imaged, and different combinations of adiabatic or non-adiabatic tip-down and flip-back pulses. Multiple RF coils transmit RF pulses in response to the pulse sequence and acquire RF data in response to transmission of the RF pulses. A processing system processes the RF data to provide a display image indicating different tissue types with enhanced discrimination based on T2 relaxation time difference or combined T2 and T1 time difference.

A system and method for recovering erased symbols in a wireless communication is provided. The system and method includes a receiver configured to receive encoded data transmissions. The receiver includes a single stage decoder configured to perform a decoding operation. The single stage decoder also is configured to determine a symbol erasure rate, the symbol erasure rate defined by a number of erased symbols. The single stage decoder further is configured to generate a recovery matrix based on the symbol erasure rate and invert the recovery matrix. Thereafter, the single stage decoder recovers the erased symbols based on a function of the inverted recovery matrix.

The invention discloses an imaging method for MRI contrast enhancement. Optimized inversion pulses are utilized to replace inversion pulses of a conventional inversion recovery sequence in MRI and to restore delay time, under the precise control of the optimized pluses, spin of different tissue will be evolved towards the trend of maximization of longitudinal magnetic moment differences, and the maximum longitudinal magnetic moment difference is obtained at the end moment of the pluses; on that basis, 90-degree excitation read pluses are applied to enable the maximized magnetic moment difference among the tissue to be turned over to a transverse plane, gradient echo signals are collected to form k spatial data, and the purpose of contrast enhancement among the tissue can be finally achieved through improvement on a phase sensitive image reconstruction method. According to the imaging method, the problem of too long scanning time of the conventional inversion recovery sequence is solved, the advantages of flexibility of optimized pulse waveforms and flexibility of the phase sensitive image reconstruction method are fully utilized, use of expensive magnetic resonance contrast media can be avoided, and the imaging method is superior to an existing MRI contrast enhancement method both in performance and in cost.

With the objective of generating an imaging area including fluid with desired image quality at a subject and enhancing image quality, a first inversion recovery pulse is transmitted so as to invert spins in a second subject region which includes a first subject region used as the imaging area and is broader than the first subject region, before execution of a pulse sequence corresponding to an FSE method at every TR in an imaging sequence. After the execution of the pulse sequence corresponding to the FSE method, a second refocus pulse is transmitted so as to cause spins in a third subject region including the first subject region and wider than the first subject region to reconverge. A fast recovery pulse is transmitted to selectively recover spins in the first subject region. Thereafter, a second inversion recovery pulse is transmitted so as to invert the spins in the second subject region.

A system and method for generating simulated post-contrast T1-weighted magnetic resonance (MR) images without the use of exogenous contrast material based upon patient-specific non-contrast MR images using machine learning/artificial intelligence techniques to train the system to generate post-contrast T1-weighted magnetic resonance images based upon retrospectively collected non-contrast MR images of various sequence types including T1-weighted, T2-weighted, FLAIR (Fluid-Attenuated Inversion Recovery), and/or DWI (Diffusion-Weighted Imaging).

The invention discloses a nuclear-magnetic-resonance-technology-based method for detecting transformer oil ageing state parameters. The ageing state parameters comprise oil sample viscosity, oil sample density, oil sample furfural content, oil sample resistance and the like. The method comprises the following steps: performing nuclear magnetic resonance spectrum analysis on a solution gas-containing transformer oil sample and detecting the parameters, wherein the oil sample viscosity eta is measured through the formula shown in the abstract, T1 and T2 respectively refer to longitudinal/transverse relaxation time of the oil sample, T1 is measured by an inversion recovery method, T2 is measured by a CPMG method, the oil sample density and the other parameters are measured by measuring the content of CHn functional groups in the oil sample by utilizing a two-dimensional J-resolved spectroscopy nuclear magnetic resonance analysis method according to a relation model between the content of functional groups and the oil sample density and other parameters; and n in the CHn is equal to 0, 1, 2 and 3. The method has the advantages of few sample quantity, simple and direct sampling process, high analysis speed, high analysis accuracy and the like.

Embodiments of the invention disclose a magnetic resonance imaging method and system. The method comprises the following steps: applying non-layering inverse pulses to a detected object; simultaneously stimulating multiple layers of a heart by using a preset imaging sequence in a set heart movement phase in a first heartbeat period, and acquiring a multilayer aliasing T1 weighted image of the heart; acquiring a reference image by using a preset imaging sequence stimulated by a preset overturning angle in a set heart movement phase in a second heartbeat period, wherein the first heartbeat period and the second heartbeat period correspond to a same breath-holding and are two adjacent heartbeat periods, and the reference image corresponds to one layer of the multiple layers; and performing the interlayer de-aliasing and phase-sensitive reverse restoration re-establishment for the multilayer aliasing T1 weighted image by using the reference image to obtain a target T1 weighted image of each layer of the heart. By virtue of the technical scheme, on the premise of ensuring the image quality, the magnetic resonance data acquisition efficiency can be improved.

The invention discloses a myocardium T1 quantifying method. The method includes the steps that after electrocardiograph gating trigger delay, non-layer-selection inversion pulses are applied; real-time interlaced collection of at least two layers of images is carried out with a fast spoiled gradient echo low-angle shot sequence of a radial sampling trajectory, and the inversion recovery process of signals is captured; a sampling line in diastole is selected to serve as a K space center line; with the selected sampling line as the center, the sampling line is symmetrically selected to carry out image reconstruction according to the size of a reconstruction window; a T1 quantifying graph is fitted with restructured images. The invention further discloses a device based on the method. By means of the method and the device, multiple layers of T1 quantifying images can be collected in one time of breathholding, the whole heart can be covered in two or three times of breathholding, and thus time waste and patient discomfort caused by breathholding are reduced.

A system for cardiac MR imaging receives a heart rate signal representing heart electrical activity. The system, over multiple successive heart cycles, uses multiple MR imaging RF coils in gradient echo imaging a patient heart, synchronized with the heart rate signal and uses an inversion recovery pulse for inverting myocardium tissue MR signal for an individual heart cycle, to acquire, within multiple individual successive portions of an individual heart cycle, corresponding successive multiple patient heart images. An individual image of an individual heart cycle portion is derived from multiple heart image representative data sets comprising a reduced set of k-space data elements acquired using corresponding multiple coils of the RF imaging coils. An image generator generates an MR image of an individual heart cycle portion using the multiple heart image representative data sets comprising the reduced set of k-space data elements.

The invention relates to a method of MR imaging of at least a portion of a body (10) of a patient placed in an examination volume of an MR device (1). The acquisition of high-resolution three-dimensional FLAIR images as well as T2-weighted images at high main magnetic field strength (>3 Tesla) results in unacceptable long scan times. The present invention contemplates a new and improved MR imaging method which overcomes this problem. The method of the invention comprises the steps of subjecting the portion of the body (10) to a first imaging sequence (S1) for acquiring a first signal data set; immediately subsequent to the first imaging sequence (S1) subjecting the portion of the body (10) to an inversion RF pulse that inverses longitudinal magnetization within the portion; after an inversion delay period (TI) subjecting the portion of the body (10) to a second imaging sequence (S2) for acquiring a second signal data set; reconstructing first and second MR images from the first and second signal data sets respectively.

Systems and methods related to imaging biomarkers for determining neurological disease states of a subject are provided. In one embodiment, a method for producing an image indicative of a neurological disease using a magnetic resonance imaging (“MRI”) system is provided. The method includes directing the MRI system to perform a double inversion-recovery (“DIR”) pulse sequence to generate data where signals from gray matter and cerebral spinal fluid are substantially suppressed. The method also includes analyzing the DIR images, reconstructed from the acquired data, to identify cortical and white matter lesions. This includes identifying imaging biomarkers based on visual signatures of brain tissue, including white matter tissue. In some aspects, diffusion-weighted data may also be obtained using the MRI system. Diffusion-weighted data may be used in a tractography process to determine connectivities, or connectivity patterns between the identified lesions, including cortical lesions, to determine neurological disease states of the subject.