404 results about "Radiofrequency coil" patented technology

Apparatus and method for using radio frequency coil systems for magnetic resonance imaging within an open architecture apparatus is provided. The MRI coil system includes a support structure with an open architecture in which secondary support structures, compression systems and plates containing RF coil systems may be introduced. These structures and RF coils can be moved relative to the patient, or removed entirely from the system. In one embodiment the system consists of a tabletop coil system, while another embodiment consists of a dedicated stretcher design.

A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

A magnetic resonance imaging (MRI) system, comprising: a magnetics system comprising: a B₀ magnet configured to provide a B₀ field for the MRI system; gradient coils configured to provide gradient fields for the MRI system; and at least one RF coil configured to detect magnetic resonance (MR) signals; and a controller configured to: control the magnetics system to acquire MR spatial frequency data using non-Cartesian sampling; and generate an MR image from the acquired MR spatial frequency data using a neural network model comprising one or more neural network blocks including a first neural network block, wherein the first neural network block is configured to perform data consistency processing using a non-uniform Fourier transformation.

When an RF coil in a magnetic resonance imaging system includes a plurality of conductive members and circuit elements connected to the conductive members, at least part of each of the conductive members is formed to a thickness so as to dissipate heat generated from the circuit elements. Moreover, the magnetic resonance imaging system is configured to include a cooling unit that circulates cooling air over the surfaces of the circuit elements provided in the RF coil.

A two-dimensional (2D) chemical shift correlated MR spectroscopic (COSY) sequence integrated into a new volume localization technique (90°-180°-90°) for whole body MR Spectroscopy. Using the product operator formalism, a theoretical calculation of the volume localization as well as the coherence transfer efficiencies in 2D MRS is presented. A combination of different MRI transmit/receive rf coils is used. The cross peak intensities excited by the proposed 2D sequence are asymmetric with respect to the diagonal peaks. Localized COSY spectra of cerebral frontal and occipital gray/white matter regions in fifteen healthy controls are presented.

A magnetic resonance imaging (MRI) system, comprising: a magnetics system comprising: a B₀ magnet configured to provide a B₀ field for the MRI system; gradient coils configured to provide gradient fields for the MRI system; and at least one RF coil configured to detect magnetic resonance (MR) signals; and a controller configured to: control the magnetics system to acquire MR spatial frequency data using non-Cartesian sampling; and generate an MR image from the acquired MR spatial frequency data using a neural network model comprising one or more neural network blocks including a first neural network block, wherein the first neural network block is configured to perform data consistency processing using a non-uniform Fourier transformation.

A gamma ray detector ring for a combined positron emission tomography (PET) and magnetic resonance imaging (MRI) system is integrated into a radio frequency (RF) coil assembly such that the detector ring is integrated with a RF shield. Each gamma ray detector in the detector ring includes a scintillator component that emits light when a gamma ray is detected and a photodetector component designed to be sensitive to the frequency of light produced by the scintillator. A RF shield may be integrated into a detector ring such that the RF shield is positioned between the scintillator and photodetector components of each detector, thereby saving valuable radial space within the imaging system. Multiple such detector rings may be located adjacent to one another to increase axial coverage and enable three-dimensional PET imaging techniques.

A transverse rf saddle coil (30) for use in NMR is affixed in intimate thermal conract on one surface of a ceramic coilform (23) of high thermal conductivity. The probe is mostly for use with solid samples at high fields where the axis of the coilform is not alignedwith the main field. An orthogonal rf coil (1) is mounted in intimate thermal contact to the first saddle coil (30) via a ceramic spacer or coilform (2). The coilform is cooled by high-velocity gas flow and is also often associated with bearing exhaust gas from a high speed sample spinner. The two coils are tuned to different rf frequencies with circuits capable of supporting high rf currents. The rf coils (30, 1) may be magnetically compensated and expansion controlled, and passive geometric compensation of magnetic susceptibility effects from a sample spinner stator may also be incorporated. Novel coil mounting techniques, including metallurgical bonds to ceramics and capturing by dielectric clam-shells, are also disclosed.

In one aspect, the present invention provides a cylindrical meanderline coil that can significantly improve the performance and usefulness of nuclear magnetic resonance (NMR) catheter radiofrequency (RF) coils by shaping the spatial dimensions of the volume of excitation and reception of signal. This can provide improved accuracy in defining the volume of excitation and reception of the subject or specimen, and increase the signal to noise ratio of a received signal. In another aspect, the invention provides an intravascular catheter having a coil at its tip for generating and/or detecting magnetic excitations. A preamplifer coupled to the catheter in proximity of the coil allows amplifying signals generated and/or detected by the coil. Although in one application, a coil and/or a catheter of the invention can be employed, for example, for MR spectroscopy or imaging of biological tissue, such as atherosclerotic plaques arterial walls in the human body, the invention provides similar advantages in any situation where a magnetic resonance or other magnetic induction signal is to be received from a thin cylindrical shell or sector of a cylindrical shell.

A system wirelessly supplies electrical power to an RF coil and an analog-to-digital converter (ADC) for an MRI system. The system supplies power to at least operate the RF coil and ADC without the use of a battery and without use of a wired connection external to the bore of the magnet.

A magnetic resonance imaging apparatus of the invention comprises a static magnetic field generation unit which generates a static magnetic field in a gantry, a gradient magnetic field generation unit which applies a gradient magnetic field to a object in the static magnetic field, a radio frequency coil which receives a magnetic resonance signal from the object to which the gradient magnetic field is applied, a contour detection unit which detects a contour of the object, a coil movement unit which moves the radio frequency coil on the basis of the detected contour while the radio frequency coil is placed near and far relative to the object, and an image generation unit which generates a magnetic resonance image on the basis of the received magnetic resonance signal.

A method and apparatus for acquiring high resolution MR images of a carotid artery. A six-channel RF coil array has three RF coils placed in an overlapping pattern and positioned adjacent to a first region-of-interest (ROI) of an imaging patient. The six-channel RF coil also has three RF coils placed in an overlapping pattern and positioned adjacent to a second ROI of an imaging patient.

An RF coil assembly for use in a multiple receive-channel MRI system is provided. The RF coil assembly is configured as a multi-turn-element RF coil assembly 200 to operate as a surface-coil array in cooperation with the MRI system 100 which is configured to operate in a multiple-channel receive mode.

A magnetic resonance imaging apparatus has a static field magnet, gradient coils, a gantry including an opening and storing the static field magnet the gradient coils, a bed structure for advancing and retreating a table-top, on which an object can be placed, with respect to the opening, a lower coil formed by a radio frequency coil disposed below the table-top, and a movement control unit configured to control the lower coil to be movable.

Nuclear magnetic resonance systems and methods of use thereof are provided. The systems employ implantable radiofrequency coils (105) and optionally implantable magnets (101). The systems can employ weak permanent magnets and/or permanent magnets that provide magnetic fields that are much less homogeneous than in conventional systems. This allows, for example, for inexpensive and simple probeheads for nuclear magnetic resonance relaxometry with suitable biosensors. The methods of the present invention allow in-vivo magnetic resonance measurements and, in particular, monitoring of analytes and determination of medical diagnostic information, for example, based on determined magnetic resonance parameters.

A short radio frequency coil for magnetic resonance imaging of the head to provide a homogeneous magnetic field including parallel conductors forming a first cylindrical portion with end rings supporting the conductors which then continue at an angle to form the frustum of a cone and further continuing to form a reduced diameter second cylindrical portion. A third conductive end ring of reduced diameter positioned at the open end of the second cylindrical portion supports the end of the conductors and provides a reduced diameter opening. An asymmetrical coil surrounds portions of the radio frequency coil including the first cylindrical and frustum of a cone portions.

An RF coil docking station (30) comprises: an RF coil receptacle (32, 34, 36, 38) configured to receive and store an RF coil (20, 22, 24) and to convey data between the RF coil docking station and the stored RF coil (22, 24); and a processor (46, 54) configured to control conveyance of data between the RF coil docking station and the stored RF coil to modify an operational state of the stored RF coil. In some embodiments, the RF coil docking station (30) comprises a plurality of RF coil receptacles (32, 34, 36, 38) configured to receive and store RF coils and to identify the stored RF coils, the processor is configured to select one or more of the stored RF coils for performing an identified magnetic resonance procedure (90), and an indicator (52, 55) is configured to indicate the selected one or more of the stored RF coils.

For the purpose of changing the geometry of and spacing between loop coils incorporated into an RF coil without moving the RF coil, a first plurality of loops having a geometry optimized for a square sum method employing a phased array, and a second plurality of small loops having a geometry optimized for a sensitivity encoding method are switched by switching elements for an open/close operation using a diode, and at the same time, a first decoupling means and a second decoupling means are switched. Thus, an operator is not required to replace the RF coil positioned on a cradle, and the first plurality of loops for the square sum method employing a phased array and the second plurality of small loops for the sensitivity encoding method can be switched by electronic switching and can be used as RF coils.