650 results about "Magnet resonance imaging" patented technology

Method and apparatus for determining the instantaneous location, the orientation of an object moving through a three-dimensional space by applying to the object a coil assembly including a plurality of sensor coils (20) having axes of known orientation with respect to each other including components in the three orthogonal planes; generating a time-varying, three-dimensional magnetic field gradient having known instantaneous values of magnitude and direction; applying the magnetic field gradient to the space, and object moving therethrough to induce electrical potentials in the sensor coils; measuring the instantaneous values of the induced electrical potentials generated in the sensor coils; processing the measured instantaneous values generated in the sensor coils together with the known magnitude, direction of the generated magnetic field gradient, the known relative orientation of the sensor coils in the coil assembly to compute the instantaneous location, orientation of the object within the space.

An electromagnetic shield has a first patterned or apertured layer having non-conductive materials and conductive material and a second patterned or apertured layer having non-conductive materials and conductive material. The conductive material may be a metal, a carbon composite, or a polymer composite. The non-conductive materials in the first patterned or apertured layer may be randomly located or located in a predetermined segmented pattern such that the non-conductive materials in the first patterned or apertured layer are located in a predetermined segmented pattern with respect to locations of the non-conductive materials in the second patterned or apertured layer.

Computed Tomography (CT) and Magnetic Resonance Imaging (MRI) are commonly used to assess patients with known or suspected pathologies of the lungs and liver. In particular, identification and quantification of possibly malignant regions identified in these high-resolution images is essential for accurate and timely diagnosis. However, careful quantitative assessment of lung and liver lesions is tedious and time consuming. This disclosure describes an automated end-to-end pipeline for accurate lesion detection and segmentation.

A system for determining the level of shielding in a magnetic resonance imaging (MRI) apparatus and for real-time reduction of noise produced during MRI data acquisition. The system includes: at least one antenna; data acquirer in communication with the at least one antenna and in communication with the RF pulse generator; and a synchronizer for synchronizing the acquisition of data by the data acquirer with MRI pulses being produced by the MRI apparatus.

An apparatus and method is provided for improving the quality of electrocardiogram (ECG) signals obtained from a patient undergoing magnetic resonance imaging (MRI) wherein the ECG signal has relatively high levels of noise or interference voltages induced on it by changing magnetic fields. The apparatus includes the arrangement of a differential amplifier, a prefilter, a signal limiter (SL) circuit and an intermediate amplifier with an integral low pas filter. The prefilter limits the rise time or high frequency component of the noise or interfering voltages induced on the ECG that are presented to the signal limiter.

An RFID tag for use with an MRI machine has an integrated circuit and structure for protecting it from damage when exposed to an intense MRI RF transmitter field. The structure for protecting the integrated circuit may include a controllable low impedance device coupled across the integrated circuit, a controllable high impedance device coupled in series with the integrated circuit, and/or frequency selective RF filter.

Apparatus, system and method for immobilizing a patient's head during imaging. The apparatus includes two substantially C-shaped members that are pivotably mounted to each other. One C-shaped member includes at least one adjustable positioning rod for securing the patient's head during imaging. The apparatus is attached to a magnet resonance imaging apparatus to form a system. The system is used for imaging a patient whose head and neck is immobilized by the apparatus.

The invention is an apparatus and method for treatments and targeted drug delivery into a living patient, particularly but not exclusively using magnetic resonance (MR) imaging. The apparatus and method are useful in delivery to all types of living tissue and uses MR Imaging to track the location of drug delivery and estimating the rate of drug delivery. An MR-visible drug delivery device positioned at a target site (e.g., intracranial delivery) delivers a diagnostic or therapeutic drug solution into the tissue (e.g., the brain). The spinal distribution kinetics of the injected or infused drug agent are monitored quantitatively and non-invasively using water proton directional diffusion MR imaging to establish the efficacy of drug delivery at a targeted location.

An antenna (100) for a magnetic resonance device has a predetermined sensitivity and is designed to excite and/or detect a magnetic resonance in an object under test. The antenna (100) includes a stripline resonator (10) that is equipped with at least one stripline (11), and a conductor loop arrangement (20) that adjoins the stripline resonator (10) and forms at least one conductor loop (21, 22, 28) which is interrupted by at least one capacitor (23). The sensitivity of the antenna (100) is formed by overlapping sensitivity profiles of the stripline resonator (10) and the conductor loop arrangement (20). Also described are an antenna array (200) including a plurality of antennas (100), a magnetic resonance device (300) including at least one antenna (100) or antenna array (200), and methods for magnetic resonance imaging or magnetic resonance spectroscopy.

The present invention relates to an apparatus for providing high resolution images to patients positioned in a magnetic resonance imaging (MRI) device (3), the MRI device (3) comprising a head coil (21), the head coil arranged to surround a patient's (5) head and to provide MRI images thereof, the apparatus comprising means (12, 13, 14) for receiving video or picture image signals from an external source. According to the present invention, the apparatus further comprises means (14, 28, 34, 29) for displaying a video or picture image, said display means being arranged in a housing (20), said housing (20) being suspended in an arm comprising at least two successive members (38, 39), wherein a joint (40) between the housing (20) and the adjacent member (38), a joint or joints (41) between the successive members (38, 39), and a joint (42) between an attachment element (16) for attaching the apparatus to the head coil (21), or other part of the MRI device (3), and the member (39) adjacent to the coil attachment element (16), each is hinged to allow rotation of the joints (40, 41, 42).

A radio frequency (“RF”) shielded and acoustically isolated enclosure that efficiently employs multiple layers of sound insulation and absorbs airborne noise and the noise provided by magnetic resonance imaging (“MRI”) equipment through the supports of such equipment. The RF enclosure uses multiple layers and types of insulating materials positioned to maximize the noise absorption of the RF enclosure. This reduces the cost and space required by the enclosure. In one embodiment the enclosure includes a ceiling, a floor and a plurality of walls. The ceiling and walls include one or more multiple layers of different insulating materials that either abut each other or form air gaps. In one embodiment the floor includes a heavy metal plate on which the MRI equipment sits. The plate elastically couples to a conductive shield. The elastic coupling attenuates certain frequencies above the natural frequency of the metal sheet.

The present invention relates to minimally invasive X-ray guided interventions, in particular to an image processing and rendering system and a method for improving visibility and supporting automatic detection and tracking of interventional tools that are used in electrophysiological procedures. According to the invention, this is accomplished by calculating differences between 2D projected image data of a preoperatively acquired 3D voxel volume showing a specific anatomical region of interest or a pathological abnormality (e.g. an intracranial arterial stenosis, an aneurysm of a cerebral, pulmonary or coronary artery branch, a gastric carcinoma or sarcoma, etc.) in a tissue of a patient's body and intraoperatively recorded 2D fluoroscopic images showing the aforementioned objects in the interior of said patient's body, wherein said 3D voxel volume has been generated in the scope of a computed tomography, magnet resonance imaging or 3D rotational angiography based image acquisition procedure and said 2D fluoroscopic images have been co-registered with the 2D projected image data. After registration of the projected 3D data with each of said X-ray images, comparison of the 2D projected image data with the 2D fluoroscopic images—based on the resulting difference images—allows removing common patterns and thus enhancing the visibility of interventional instruments which are inserted into a pathological tissue region, a blood vessel segment or any other region of interest in the interior of the patient's body. Automatic image processing methods to detect and track those instruments are also made easier and more robust by this invention. Once the 2D-3D registration is completed for a given view, all the changes in the system geometry of an X-ray system used for generating said fluoroscopic images can be applied to a registration matrix. Hence, use of said method as claimed is not limited to the same X-ray view during the whole procedure.

An MRI apparatus excellent in magnetic field generation efficiency is provided. According to this invention, a main coil (52) of a gradient magnetic field coil (13) is partially recessed to reduce the total thickness of a radio-frequency coil (11) and a gradient magnetic field coil (13). That is, the main coil (52) is designed in a tubular shape, and the diameter r1 at the center portion of the imaging space is larger than the diameter r2 of the main coil end portion. Accordingly, the RF coil (11) can be disposed to be near to the gradient magnetic field coil (13) side without lowering the magnetic field generation efficiency.

The invention relates to a birdcage coil for a magnetic resonance imaging system and a tuning method thereof. The birdcage coil comprises an upper annular conductor, a lower annular conductor and a plurality of linear conductors which are distributed on a cylindrical surface, wherein the linear conductors are connected between the upper annular conductor and the lower annular conductor. A plurality of capacitors are connected in series in the upper annular conductor and the lower annular conductor. The whole or a part of the linear conductor is flexibly bendable and deformable. The distance between the upper annular conductor and the lower annular conductor is changed when the degree of bending deformation of the linear conductor is adjusted so that the resonant frequency of the birdcage coil is changed. The resonant frequency is adjusted by changing the position of a debugging ring. Thus, an expensive adjustable capacitor device is replaced so as to reduce the cost of the birdcage coil. The birdcage coil can be easily debugged at the installation site of the magnetic resonance system. The structure of the whole birdcage coil is adjusted synchronously and a large tuning range is achieved. The distribution of coil current and the uniformity of an RF magnetic field inside the coil are not influenced. The birdcage coil is stable in mechanical structure and can withstand high voltage.

A RF coil compression system for use with an MRI system configured to image a patient's breast is disclosed. In one embodiment, the compression system comprises a first compression plate comprising a first plurality of RF coil elements, which is positioned in a plane oriented orthogonal to a direction of the main magnetic field and the first RF coil elements having a reception sensitivity to a B1 field and is orthogonal to a main magnetic field of the MRI system. The compresses system may further comprise a second compression plate, configured to be positioned opposing the first compression plate and orthogonal to the superior-inferior direction, the second compression plate comprising a second plurality of RF coil elements, the second RF coil elements having a reception sensitivity to a B1 field oriented in a direction substantially orthogonal to the first direction and to the main magnetic field of the MRI system.

The invention discloses a rapid magnetic resonance imaging method based on an AR2 U-Net neural network. According to the method, an existing R2U-Net convolutional neural network is improved; the method is based on an R2U-Net convolutional neural network. An attention gate module is added, an AG training model is used for implicitly learning and suppressing an unrelated region in an input image, and meanwhile, obvious features useful for a specific task are highlighted, so that the AR2 U-Net convolutional neural network only needs a small amount of training data under the condition of reconstructing an image with the same quality. The problem that the swing amplitude of an optimization loss function is too large in the updating process is solved. According to the method, an Adam optimization algorithm is adopted to replace a conventional SGD optimization algorithm, the convergence rate of the convolutional network can be further increased, the problem that training is ended too early can be effectively prevented, and for learning rate processing, a polynomial attenuation strategy is adopted, so that learning can be stably reduced, and the reduction speed is higher along with increase of the number of turns.

Embodiments of the present invention generally pertain to implantable medical devices, and methods for use therewith, that detect exposure to magnetic fields produced by magnetic resonance imaging (MRI) systems. In accordance with specific embodiments, a sensor output is produced using an implantable sensor that is configured to detect acceleration, sound and/or vibration, but is not configured to detect a magnetic field. Such a sensor can be an accelerometer sensor, a strain gauge sensor or a microphone sensor, but is not limited thereto. In dependence on the produced sensor output, there is a determination whether of whether the IMD is being exposed to a time-varying gradient magnetic field from an MRI system. In accordance with certain embodiments, when there is a determination that the IMD is being exposed to a time-varying gradient magnetic field from an MRI system, then a mode switch to an MRI safe mode is performed.

A method and apparatus for enhancing detection of a ferromagnetic threat object by magnetizing the threat object with a separate magnetic field, prior to scanning of the subject by a ferromagnetic-detecting sensor system.

The invention relates to a double-mode imaging and medicine-loading integrated nano medicine carrier and a preparation method thereof. The nano medicine carrier is characterized in that nanoparticles are formed by wrapping functional nanocrystal and anti-tumor medicines through using biodegradable macromolecular polymers; the size of the nano medicine carrier is less than 500 nm; and the nano medicine carrier has a smooth surface and is regular in particle size. The nano medicine carrier is prepared by at least one of a precipitation method, a micellar method and a microemulsion method. The microemulsion method comprises the following steps of: preparing the functional nanocrystal, the anti-tumor medicines and the biodegradable macromolecular polymers into liquid respectively; mixing and stirring to form microemulsion; and curing nanospheres with stirring, centrifugally separating the nanospheres, cleaning and freeze-drying to prepare the double-mode imaging and medicine-loading integrated nano medicine carrier. According to the technical scheme, double functions of tumor fluorescence diagnosis and magnetic resonance imaging of the nano medicine carrier are realized; sustained release of the medicines and targeted medicine supply are realized; and toxic or side effect and damage to the normal tissue caused by high-dose multiple administration are greatly reduced.

A magnetic resonance imaging system has a superconducting magnet housed within a cryostat, a cryogenic refrigerator that cools within the cryostat, a helium compressor that supplies compressed helium to the cryogenic refrigerator and to receive a return flow of compressed helium from the refrigerator, and a magnet supervisory system controlling operation of the magnet resonance imaging system. An apparatus is provided for controlling the speed and/or timing of operation of the helium compressor in accordance with predefined algorithms in response to system state data.

A system and method for magnetic field distortion compensation includes a cryostat for a magnetic resonance imaging (MRI) system. The cryostat includes a vacuum casing having a vacuum therein. A cryogen vessel is disposed within the casing, the vessel having a coolant therein. A thermal shield is disposed between the vacuum casing and the cryogen vessel. An eddy current compensation assembly is disposed within the casing. The eddy current compensation assembly includes a plurality of electrically conductive loops formed on one of the vacuum casing, the cryogen vessel, and the thermal shield and constructed to mitigate vibration-induced eddy currents in the MRI system.