1208 results about "Magnetic resonance imagery" patented technology

An obturator as part of a biopsy system enhances use with Magnetic Resonance Imaging (MRI) by indicating location of a side aperture in an encompassing cannula. The cannula (e.g., detached probe, sleeve sized to receive a core biopsy probe) includes a side aperture for taking a tissue sample. When the obturator is inserted in lieu of the biopsy device into the cannula, a notch formed in a shaft of the obturator corresponds to the side aperture. A dugout trough into the notch may further accept aqueous material to further accentuate the side aperture. In addition, a series of dimensionally varied apertures (e.g., wells, slats) that communicate through a lateral surface of the shaft and that are proximal to the side aperture receive an aqueous material to accentuate visibility in an MRI image, even in a skewed MRI slice through the cannula/obturator.

Techniques for removing artefacts, such as RF interference and/or noise, from magnetic resonance data. The techniques include: obtaining input magnetic resonance (MR) data using at least one radio-frequency (RF) coil of a magnetic resonance imaging (MRI) system; and generating an MR image from input MR data at least in part by using a neural network model to suppress at least one artefact in the input MR data.

The invention relates to highly fluorescent metal oxide nanoparticles to which biomolecules and other compounds can be chemically linked to form biocompatible, stable optical imaging agents for in vitro and in vivo applications. The fluorescent metal oxide nanoparticles may also be used for magnetic resonance imaging (MRI), thus providing a multi modality imaging agent.

A generalized multi-point fat-water separation process is combined with steady-state free precession (SSFP) to obtain high quality images of articular cartilage with reduced imaging time.

A magnetic resonance imaging apparatus including a magnetic structure having two opposite and spaced apart poles and a column or wall transverse to the poles and connecting the poles; the poles defining two opposite walls delimiting a patient-imaging space, the two opposite walls extending along substantially parallel planes which are substantially parallel to a vertical plane; and a patient positioning table which is slidably connected to a supporting frame between the two poles; the table being positioned with its longitudinal axis substantially parallel to the two opposite parallel walls of the poles and the table being oriented with its transverse axis perpendicular to at least one of the two opposite walls.

A medical device suitable for use with magnetic resonance imaging techniques includes a component that is formed from a refractory metal, a precious metal, an alloy comprising a refractory metal, an alloy comprising a precious metal, and/or alloy comprising at least one refractory metal and at least one precious metal. The component has a magnetic susceptibility less than about 300×10⁻⁶ cgs, and has a low radiopacity such that the component can be visualized under fluoroscopy.

The invention relates to the research field of magnetic resonance imaging and provides a method and a system for tracking a tested space attitude, dynamically adjusting imaging parameters of a scanner in real time and avoiding acquisition of motion artifact images in the acquisition process of magnetic resonance imaging data based on a computer vision target recognition and tracking technology. By adopting at least two video cameras for simulating stereoscopic vision of human eyes, a target is recognized, the tested space attitude is calculated, and space motion of the space attitude is monitored and judged. Once the motion occurs, parameters of the corrected space attitude are calculated immediately and are transmitted to the scanner through a transmission control protocol/internet protocol (TCP/IP), the imaging parameters of the scanner are adjusted in real time, the scanner is ensured to be capable of acquiring image data at a correct space position under the condition that the motion of the tested space attitude exists, and accordingly finally-obtained images are like images acquired under the condition that the motion of the tested space attitude does not occur. Therefore, acquired image data are stable and reliable in quality, the motion artifact is eliminated completely, and motion correction is not required in post-processing.

A magnetic resonance imaging (MRI) method is disclosed for generating and identifying water and fat separated MR images. Image data is first acquired to obtain two echo images with the water and fat signals orthogonal in the first echo image, and parallel/anti-parallel in the second echo image. The effect of background field inhomogeneties are removed, and water and fat images are separated from each other. The separated water and fat images are identified according to the difference of their precessing frequencies.

The invention provides an embolism material composition as well as preparation method and use thereof, the embolism material composition is prepared from reactant raw materials, wherein the reactant raw materials comprise a biocompatibility material, a roentgenopaque substance and a magnetic resonance imaging substance, the roentgenopaque substance and the magnetic resonance imaging (MRI) substance are covered by the biocompatibility material. The embolism material composition not only can be directly detected by an X-ray image device, but also can be directly detected by the MRI, so that a doctor can select a detection method according to self condition of a patient and the medical device condition.

A multi-point chemical species (e.g., water, fat) separation process which is compatible with rapid gradient echo imaging such as SSFP uses an iterative least squares method that decomposes water and fat images from source images acquired at short echo time increments. The single coil algorithm extends to multi-coil reconstruction with minimal additional complexity.

Systems and methods for landmark correction in Magnetic Resonance Imaging (MRI) are provided. One method includes acquiring at least one calibration image or at least one localizer image of an object, identifying in the calibration or localizer images a region of the object as a reference point, wherein the reference point defines a landmark position. The method further includes determining an offset between an initial landmark position and the identified landmark position. The method also includes using the determined offset for MRI.

The SAR exposure of a subject undergoing an MRI examination is measured by acquiring a thermal image that indicates that temperature increase caused by the SAR exposure. This measurement may be used in a prescan process to adjust the SAR load produced by a prescribed imaging pulse sequence, and it can be used during the scan to adjust the SAR load produced by the prescribed imaging pulse sequence.

A method for reconstructing a sequence of magnetic resonance (MR) images of an object under investigation, includes the steps of (a) providing a series of sets of image raw data including an image content of the MR images to be reconstructed, the image raw data being collected with the use of at least one radiofrequency receiver coil of a magnetic resonance imaging (MRI) device, wherein each set of image raw data includes a plurality of data samples being generated with a gradient-echo sequence, in particular a FLASH sequence, that spatially encodes an MRI signal received with the at least one radiofrequency receiver coil using a non-Cartesian k-space trajectory, each set of image raw data includes a set of homogeneously distributed lines in k-space with equivalent spatial frequency content, the lines of each set of image raw data cross the center of k-space and cover a continuous range of spatial frequencies, and the positions of the lines of each set of image raw data differ in successive sets of image raw data, and (b) subjecting the sets of image raw data to a regularized nonlinear inverse reconstruction process to provide the sequence of MR images, wherein each of the MR images is created by a simultaneous estimation of a sensitivity of the at least one receiver coil and the image content and in dependency on a difference between a current estimation of the sensitivity of the at least one receiver coil and the image content and a preceding estimation of the sensitivity of the at least one receiver coil and the image content.

The present invention is a technique and apparatus for providing preferential enhancement of an artery of interest relative to adjacent veins and background tissue by correlating the collection of a predetermined portion of data (for example, image data which is representative of the central portion of k-space) of a magnetic resonance contrast image during the arterial phase of the magnetic resonance contrast enhancement.

The invention discloses a fast and parallel dynamic MRI method based on a CS compressive sensing technology due to the fact that an existing imaging method is low in speed and high in hardware cost. The method comprises the steps that under a set accelerated factor, irrelevant sampling trajectories in k-t space are generated, and then data are collected according to the trajectories; objective functions are established by the utilization of the composite information of a dynamic MRI image sparse and low rank structure; finally, the composite regularization objective functions are solved through an FCSA, optimal solutions can be fast obtained in parallel, and therefore original dynamic MRI image sequences are rebuilt. According to the method, the limit of the classic Nyquist sampling theorem is broken through, a small number of data points are sampled randomly, joint sparse information is combined, and the dynamic MRI image sequences are rebuilt through the FCSA allowing parallel implementation. Therefore, MRI time is substantially shortened.

The invention relates to a sand-filling type clamp fastener for nuclear magnetic resonance imaging, which belongs to the technical field of scientific research apparatuses for petroleum. The sand-filling type clamp fastener is vertically inserted into a micro-imaging probe of a nuclear magnetic resonance imager, the design pressure is 0-15MPa, and the design temperature is 0-70 DEG C. The sand-filling type clamp fastener can be used for carrying out indoor experiment research on the seepage and transport properties of a multi-phase multi-component fluid in an analog core. Besides a seal ring, all components of the sand-filling type clamp fastener are made from a polyamide-imide material which does not have magnetism, meets the high-temperature high-pressure requirements and has no effect on nuclear magnetic signals. The sand-filling type clamp fastener has the advantages of compact design structure, multiple times of filling, repeatability of use, convenience of operation in an experiment process, simplicity and applicability.

A method for magnitude constrained phase contrast magnetic resonance imaging (MRI) is provided. The method utilizes an assumption that the image magnitude is shared across a series of images reconstructed from a set of phase contrast enhanced k-space data. In this manner, one common magnitude image and a plurality of phase images are reconstructed substantially contemporaneously from the acquired image data. The method is further applicable to other phase contrast MRI methods, such as phase contract velocimetry. Moreover, simultaneous phase contrast velocimetry and chemical shift imaging, in which water and fat signal separation is achieved, is provided.

The invention discloses a magnetic resonance imaging method and device. The method combines a deep network model with a conventional acceleration reconstruction method in sequence. Firstly, the deep network model is used for recovering first imaging information with a high downsampling multiple to second imaging information with a low downsampling multiple, then, the conventional acceleration reconstruction method is used for completely reconstructing the second imaging information with the low downsampling multiple, and therefore, a final magnetic resonance image is obtained. Therefore, in the magnetic resonance imaging method provided by the invention, the output training sample of the deep neural network used for magnetic resonance quick imaging is not full sampling or super-full sampling data but is downsampling data, so that the output training sample of the training deep neural network can be obtained through a conventional downsampling method, the output training sample can be obtained through short collection time, and therefore, the deep neural network can be applied to a magnetic resonance imaging application scene with limited collection time, such as abdomen scanning.

A magnetic resonance imaging apparatus comprising static magnetic field generating means for generating a static magnetic field in an imaging space, measuring means for generating a high-frequency magnetic field and a gradient magnetic field in the imaging space and measuring a nuclear magnetic resonance signal generated from an object to be examined placed in the imaging space, signal processing means for reconstructing a magnetic resonance image according to the nuclear magnetic resonance signal, control means for controlling the measuring means and the signal processing means, and display means for displaying the reconstructed magnetic resonance image obtained by the signal processing means.

The magnetic resonance imaging apparatus further comprises storing means for storing a first set of information representing an inhomogeneous distribution of the static magnetic field generated depending on the characteristic of the static magnetic field generating means and a second set of information representing an inhomogeneous distribution of the static magnetic field generated depending on the tissue of the object, setting means for setting a field of view for imaging in a desired region of the object, selecting means for selecting information corresponding to the set field of view for imaging out of the second set of information as a third set of information, and correcting magnetic field generating means for generating a correcting magnetic field according to the third set of information and the first set of the information.

A hybrid imaging system includes a magnetic resonance scanner and a second modality imaging system disposed in the same radio frequency isolation space. The second modality imaging system includes radiation detectors configured to detect at least one of high energy particles and high energy photons. In some embodiments a retractable radio frequency screen is selectively extendible into a gap between the magnetic resonance scanner and the second modality imaging system. In some embodiments shim coils are disposed with the magnetic resonance scanner and are configured to compensate for distortion of the static magnetic field of the magnetic resonance scanner produced by proximity of the second modality imaging system.