42 results about "Arterial spin labeling" patented technology

This invention relates to the use of a quantitative functional MRI (fMRI)—arterial spin-labeling perfusion MRI or absolute T2 mapping MRI or a combination thereof in the non-invasive neuroimaging of a subject's brain in response to stress-inducing psychological stimuli, which can be utilized to predict individual stress reactivity as well as to be used as a human model for testing or optimizing psychopharmacological agents.

A method for non-contrast enhanced 4D time resolved dynamic magnetic resonance angiography using arterial spin labeling of blood water as an endogenous tracer and a multiphase balanced steady state free precession readout is presented. Imaging can be accelerated with dynamic golden angle radial acquisitions and k-space weighted imaging contrast (KWIC) image reconstruction and it can be used with parallel imaging techniques. Quantitative tracer kinetic models can be formed allowing cerebral blood volume, cerebral blood flow and mean transit time to be estimated. Vascular compliance can also be assessed using 4D dMRA by synchronizing dMRA acquisitions with the systolic and diastolic phases of the cardiac cycle.

The present invention relates to a method and system for conducting a magnetic resonance fluid flow study by conducting a labeling procedure and a control procedure and combining datasets from those procedures to create a dataset for the fluid flow study. An amplitude modulated magnetic field gradient and amplitude modulated RF irradiation may be applied during a labeling procedure. Likewise, amplitude modulated RF irradiation may be applied during a control procedure. An amplitude modulated magnetic field gradient may also be applied during the control procedure.

In one aspect, a method for imaging fluid flow and/or perfusion using spin labeling is provided. The method comprises applying a first magnetic gradient sequence at least to a labeling region, applying a first pulsed radio frequency (RF) sequence to the labeling region to label the fluid, the first pulsed RF sequence comprising a first plurality of pulses wherein an amplitude envelope is non-zero, the first plurality of pulses each separated by a respective first plurality of intervals wherein the amplitude envelope is substantially zero, and acquiring at least one first signal emitted from an imaging region a predetermined delay after applying the first pulsed RF sequence.

A magnetic resonance method and system are provided for generating real-time motion-corrected perfusion images based on pulsed arterial spin labeling (PASL) with a readout sequence such as a 3D gradient and spin echo (GRASE) image data acquisition block. The real-time motion correction is achieved by using a volumetric 3D EPI navigator that is provided during an intrinsic delay in the PASL sequence, which corrects for motion prospectively and does not extend the image data acquisition time as compared to a similar non-motion-corrected imaging procedure.

The invention discloses a brain ASL, SPECT and MRI image registration and fusion conjoint analysis method and system. Registration is respectively carried out to an ASL image and an MRI image by taking the MRI image as a standard; the ASL image and an SPECT image are fused according to different transparencies; a region to be computed is marked in the faultage of the SPECT image; a closed curve is obtained through carrying out a cubic spline interpolation to the ASL image; the volume and the gray value corresponding to the region to be computed and the gray value of an interesting region body through a circular truncated cone approach mode. According to the invention, the advantages of the ASL image reflected brain blood perfusion, the SPECT image reflected brain blood perfusion and the MRI provided brain structure change are combined; an interesting region is segmented and analyzed through providing interactive calibration operation a doctor and a medical expert; the judgement accuracy of a brain ischemic disease is improved; and iconography instructions are provided for a clinician to formulate a rational therapeutic schedule.

An MRI apparatus obtains an ASL (Arterial Spin Labeling) image of a region to be imaged in a subject by performing a scan to the region to be imaged independently in a control mode and in a tag mode according to a pulse sequence based on an ASL technique. The pulse sequence includes a velocity-selective pulse, BVS (Band-limited Velocity-Selective)-pulse, that selectively excites magnetization spins in a blood flow passing through the region to be imaged and having a constant velocity range for the spins to undergo transition to transverse magnetization, and then performs excitation to cause the transverse magnetization to flip back to longitudinal magnetization. The velocity-selective pulse is formed in such a manner that the transverse magnetization excited in each of the control mode and the tag mode gives rise to a phase shift in an opposite polarity upon velocity-selective excitation.

When brain images are inputted through MRI (Magnetic Resonance Imaging) and subjected to image processing to assist the diagnosis of brain diseases, functional and morphological images in an ASL coordinate system are inputted from the head of a subject by an ASL (Arterial Spin Labeling) imaging method using an MRI device. The inputted functional images are subjected to mask processing to extract only the region of cerebral parenchyma, and functional images of only the extracted region of the cerebral parenchyma are thereby produced and displayed to be overlaid on the morphological images. In this manner, a functional image such as a perfusion weighted image of only the region of the cerebral parenchyma can be extracted and displayed overlaid on a morphological image.

This disclosure is generally drawn to methods, systems, appliances and/or apparati related to obtaining magnetic resonance imaging (MRI) images. More specifically, the disclosure relates to obtaining MRI images using arterial spin labeling (ASL) and blood-oxygen-level dependence functional magnetic resonance imaging (BOLD-fMRI) techniques. In some examples, a method of obtaining magnetic resonance imaging (MRI) image(s) is provided. An example method may include providing arterial spin labeling (ASL) labeling, obtaining at least one ASL acquisition after ASL labeling, and obtaining at least one blood-oxygen-level dependence functional magnetic resonance imaging (BOLD-fMRI) acquisition after ASL labeling.

Systems and methods for reducing acoustic noise in a Magnetic Resonance Imaging (MRI) are provided. One method includes applying a labeling phase of an arterial spin labeling (ASL) pulse sequence to a region of interest, applying a three-dimensional (3D) radial pulse sequence to the region of interest to generate a tag image, applying a control phase of the ASL pulse sequence to the region of interest, and applying the 3D radial pulse sequence to the region of interest to generate a control image.

The invention discloses a cerebral perfusion weighted imaging method based on artery spin labeling and variable delay time, wherein the method comprises the steps: applying 180-degree pulses to a marked area, and acquiring signals on an imaging layer by adopting a rapid sequence after t time to obtain an image signal scanned for the first time; applying 180-degree pulses to the marked area, aftert+(n-1)*m time, collecting signals on the imaging layer in a rapid sequence mode, and thus obtaining image signals scanned for the n time, wherein n is greater than or equal to 3; constructing animage signal intensity-time curve according to the n scanned image signals; and calculating the image signal intensity-time curve to obtain cerebral perfusion parameters. According to the method, twice scanning of marking and unmarking is not needed, so that the sensitivity to motion is reduced; the radio frequency energy deposition is small; brain perfusion parameters such as blood volume, bloodflow, average transfer time and arrival time can be generated.

The invention discloses an Alzheimer's disease early-stage prediction model based on cerebellar function connection characteristics. The prediction model comprises a patient information collection system, an AD disease screening system, a magnetic resonance data analysis and processing system, a biomarker event feature extraction system and a risk prediction and analysis system. On the basis of magnetic resonance data, multi-modal data of structural phase magnetic resonance, resting state functional magnetic resonance and arterial spin labeling perfusion magnetic resonance are combined, and outcome and prognosis conditions of patients with different cognitive function states are predicted by using a feature classification method. And clinical doctors can select more effective treatment means. The magnetic resonance detection method combination can play a synergistic role, the evaluation efficiency of a single detection method is improved, and outcome and prognosis of a patient with cognitive impairment are effectively predicted. Compared with an existing method, the optimized combination of the method is more efficient, and the limitation that the existing method is high in cost, long in time and large in wound is reduced.

The present invention is directed to a system and method for magnetic resonance imaging including an extended Fourier transform-based velocity-selective pulse train design with a pair of refocusing pulses within each velocity encoding step and accompanying phase cycling between different velocity encoding steps. The present invention is robust to B0/B1 field inhomogen-city and eddy current effects. The utility of this technique, through a velocity-selective inversion pulse, is demonstrated in a 2D velo-city-selective arterials spin labeling study, which shows a reasonable agreement in CBF quantification with the standard PCASL method.

The invention provides for a method of operating a magnetic resonance imaging system for imaging a subject. The method comprises acquiring (700) tagged magnetic resonance data (642) and a first portion (644) of fingerprinting magnetic resonance data by controlling the magnetic resonance imaging system with tagging pulse sequence commands (100). The tagging pulse sequence commands comprise a tagging inversion pulse portion (102) for spin labeling a tagging location within the subject. The tagging pulse sequence commands comprise a background suppression portion (104). The background suppression portion comprises MRF pulse sequence commands for acquiring fingerprinting magnetic resonance data according to a magnetic resonance fingerprinting protocol. The tagging pulse sequence commands comprise an image acquisition portion (106). The method comprises acquiring (702) control magnetic resonance data (646) and a second portion (648) of the fingerprinting magnetic resonance data by controlling the magnetic resonance imaging system with control pulse sequence commands. The control pulse sequence commands comprise a control inversion pulse portion (202). The control pulse sequence commands comprise the background suppression portion (104′). The control pulse sequence commands comprise the image acquisition portion (106). The method comprises reconstructing (704) tagged magnitude images (650) using the tagged magnetic resonance data. The method comprises reconstructing (706) a control magnitude images (652) using the control magnetic resonance data. The method comprises constructing (708) an ASL image by subtracting the control magnitude images and the tagged magnitude images from each other. The method comprises reconstructing (710) a series of magnetic resonance fingerprinting images (656) using the first portion of the fingerprinting magnetic resonance data and/or the second portion of the fingerprinting magnetic resonance data. The method comprises generating (712) at least one magnetic resonance parametric map (658) by comparing the series of magnetic resonance fingerprinting images with a magnetic resonance fingerprinting dictionary.

The invention relates to the technical field of image processing, in particular to an ischemic region segmentation method and device, equipment and a storage medium, and the method comprises the steps: obtaining an apparent diffusion coefficient image of the brain of a target object; acquiring a cerebral blood flow image, a cerebral blood volume image and an artery passing time image of the brain of the target object; and processing the apparent diffusion coefficient image, the cerebral blood flow image, the cerebral blood volume image and the artery passing time image by using a pre-trained classification model to obtain an ischemic region segmentation image of the brain of the target object. According to the ischemic region segmentation method, the ischemic region is segmented by combining the diffusion weighted image information and the delayed artery spin marking perfusion image information after marking, mutual information among various images is fully utilized, and the accuracy and robustness of ischemic region segmentation are improved.

The invention relates to a method of MR imaging of at least a portion of a body (10) placed in a main magnetic field within the examination volume of a MR device (1). It is an object of the invention to facilitate the planning of an arterial spin labeling (ASL) MR imaging session and to improve the image quality in perfusion weighted MR imaging. The method of the invention comprises the following steps: acquiring angiographic MR signal data by subjecting the portion of the examined body (10) to one or more MR angiography scans; deriving quantitative blood flow parameters from the angiographic MR signal data;—computing a labeling efficiency of an ASL sequence from the sequence parameters of the ASL sequence and from the quantitative blood flow parameters; optimizing the sequence parameters by maximizing the labeling efficiency; acquiring perfusion weighted MR signal data by subjecting the portion of the body to the ASL sequence; and—reconstructing a MR image from the perfusion weighted MR signal data. Moreover, the invention relates to a MR device (1) and to a computer program for a MR device (1).