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5334966 Magnetostatic field generator for magnetic resonance imaging apparatus
New Patents
5332988 REMOVABLE COIL FORM FOR SUPERCONDUCTING NMR MAGNETS AFTi $tETHOD FOR Zhukovsky Alexander; Iwasa Yukikazu; Bobrov Emanual; Williis John E C Brighton, MA, UNITED STATES Assigned to Massachusetts Institute of Technology A superconducting coil is mounted on a permanent non-magnetic coil form by first winding an unreacted wire onto a temporary coil form made of refractory materials which can be assembled and disassembled, reacting the wound unreacted wire at high temperatures to form a superconducting coil. The temporary coil form is disassembled and the superconducting coil is transferred to a permanent coil form made of a non-magnetic material. The temporary coil form includes a bore tube and an end flange made of a refractory material and a terminal flange made of a non-magnetic refractory material. The terminal flange is removably secured to the bore tube. The end flange is positioned next to the other end of the bore tube and held in position against the tube by means of an end plate. A terminal plate is removably positioned adjacent to the bore tube. The assembly is held together by means of an axial force on the terminal and end plates. The superconductor wire can be wound around the outer surface of the bore tube to form a superconducting coil.
5333994
IX
NMR receiver/transmitter coil. An improved radial inflow turbine design results in higher efficiency for micro-turbines. A cylindrical air journal bearing at both ends provides radial stability and support. An axial thrust air bearing is formed at the end opposite the turbine blades between the sacrificial bottom of the soft capsule and a thrust ring. The high-strength ceramic is typically of a partially stabilized zirconia or hot pressed silicon nitride. The disposable capsule is typically of hexagonal boron nitride.
5334936 MAGNETIC IMAGING
RESONANCE APPARATUS
Tochigi, JAPAN Machida Yoshi Kabushiki Kaisha Toshiba
Assigned to
In a magnetic resonance imaging apparatus adapted for a spin-echo method using a 90 degrees pulse as a selective excitation pulse and a 180 degrees pulse as a refocus pulse, MI3 signal is acquired with their phase difference changed in increments of a fixed angle with each frequency encoding step. This permits the phase difference between an echo signal used for imaging and an FID signal unnecessary for imaging to be changed in increments of the fixed angle with each encoding step. Thus, a zipper artifact based on the FID signal will be produced in a position corresponding to the fixed angle in an MR image reconstructed through Fourier transform of the acquired signal. The proper setting of the fixed angle of the phase difference permits the zipper artifact to be shifted to any position in the MR image.
HIGH TEMPERATURE NMR SAMPLE SPINNER Doty F David; Spitzmesser Jonathan B; Wilson David G Columbia, SC, UNITED STATES Assigned to Doty Scientific Inc A high-strength, thin-wall ceramic cylinder partially closed at one end, with radial-inflow turbine blades ground into the partially closed end thereof, provides the rotational drive, surface protection, and burst strength necessary to contain and spin a low strength, disposable soft ceramic capsule, loaded with a sample for NMR experiments, at high rotational speeds inside an
5334966 MAGNETOSTATIC FIELD GENERATOR FOR MAGNETIC RESONANCE IMAGING APPARATUS Hiroyuki Takeshima Hirotaka, Takeuchi Ryugasaki, JAPAN Assigned to Hitachi Medical carp
New Patents
A magnetostatic field generator for a magnetic resonance imaging apparatus includes a pair of permanent magnets each having a rectangular parallelepiped shape arranged perpendicular to a direction of a uniform magnetic field to surround a space where a uniform magnetic field is generated, a plurality of first permanent magnets each having a trigonal prism shape arranged on both sides of an area between the permanent magnets each having a rectangular parahelepiped shape, a plurality of second permanent magnets each having a uigonal prism shape which are arranged between the permanent magnets each having a rectangular parallelepiped shape and the first permanent magnets and satisfy magnetic field boundary conditions between the permanent magnets each having a rectangular parallelepiped shape and the first permanent magnets, and a yoke for holding the pair of permanent magnets each having a rectangular parallelepiped shape, the plurality of first permanent magnets, and the plurality of second permanent magnets and for forming a magnetic path.
5335660
MAGNETIC RESONANCE METHOD OF MEASURING KIDNEY FILTRATION RATES Dumoulin Charles L BaIlston Lake, NY, UNITED STATES Assigned to General Electric Company A magnetic resonance imaging system employs a sequence of radio frequency pulses and magnetic field gradients to detect and measure the spinrelaxation time of moving blood within a subject. Spin-lattice relaxation times are determined by first inverting longitudinal spin magnetization and then detecting the recovery of this magnetization with a series of detection radio frequency pulses. The inversion pulse is applied to the entire subject, but the detection pulses are applied only to a selection portion of the subject. Blood motion causes the blood in the detection region to be replaced for each detection pulse, thereby increasing the accuracy of the measurement and permitting the use of multiple detection pulses after a single inversion pulse. Invivo application of this invention can be used to assessrenal function in individual kidneys.
5336762
POLYCHELATING AGENTS FOR LMAGE AND SPECTRAL ENHANCEME;;NI’(A&D SPECTRAL Banney David Dallas, TX, UNITED STATES Assigned to Access Pharmaceuticals Inc The present invention includes an imageenhancing agent comprising a biodegradable, water-soluble polymer, synthetic or naturally derived and having repeating hydrophilic monomeric units with amino or hydroxyl groups. This agent also includes chelating agents comprising functional groups bound to an amino or hydroxyl group of the monomeric units. These chelating agents have a formation constant for divalent or trivalent metal cations of at least about 108 at physiological temperature and pH. This image-enhancing agent is biodegradable to intermediary metabolites, excretable chelates, oligomers, monomers or combinations thereof of low toxicity. These image-enhancing agents may further comprise a paramagnetic metal ion for enhancement of the image arising from induced magnetic resonance signals. Images resulting from scanning of gamma particle emissions may be enhanced when the image-enhancing agent of the present invention comprises radioisotopic metal ions emitting gamma particles. The physical conversion of these image-enhancing agents into microspheres (or, less optimally, lirrther internal microaggregates) allows directioning of the image-enhancing agents to organs with phagocytic capabilities. Dextran is a preferred polymer; DTPA and gadolinium are respectively preferred chelating agents and paramagnetic metal ions.
5336988
SCALAR S-PARAMETER TEST SET FOR NMR INSTRUMENTATION MEASUREMENTS Chmielewski Thorn& Molyneaux David; Braum William 0 Highland Heights, OH, UNITED STATES Assigned to Picker International Inc An RF device (A) under test is connected with ports or jacks (14, 16) of an S-parameter test set
5332988 REMOVABLE COIL FORM FOR SUPERCONDUCTING NMR MAGNETS AFTi $tETHOD FOR Zhukovsky Alexander; Iwasa Yukikazu; Bobrov Emanual; Williis John E C Brighton, MA, UNITED STATES Assigned to Massachusetts Institute of Technology A superconducting coil is mounted on a permanent non-magnetic coil form by first winding an unreacted wire onto a temporary coil form made of refractory materials which can be assembled and disassembled, reacting the wound unreacted wire at high temperatures to form a superconducting coil. The temporary coil form is disassembled and the superconducting coil is transferred to a permanent coil form made of a non-magnetic material. The temporary coil form includes a bore tube and an end flange made of a refractory material and a terminal flange made of a non-magnetic refractory material. The terminal flange is removably secured to the bore tube. The end flange is positioned next to the other end of the bore tube and held in position against the tube by means of an end plate. A terminal plate is removably positioned adjacent to the bore tube. The assembly is held together by means of an axial force on the terminal and end plates. The superconductor wire can be wound around the outer surface of the bore tube to form a superconducting coil.
5333994
IX
NMR receiver/transmitter coil. An improved radial inflow turbine design results in higher efficiency for micro-turbines. A cylindrical air journal bearing at both ends provides radial stability and support. An axial thrust air bearing is formed at the end opposite the turbine blades between the sacrificial bottom of the soft capsule and a thrust ring. The high-strength ceramic is typically of a partially stabilized zirconia or hot pressed silicon nitride. The disposable capsule is typically of hexagonal boron nitride.
5334936 MAGNETIC IMAGING
RESONANCE APPARATUS
Tochigi, JAPAN Machida Yoshi Kabushiki Kaisha Toshiba
Assigned to
In a magnetic resonance imaging apparatus adapted for a spin-echo method using a 90 degrees pulse as a selective excitation pulse and a 180 degrees pulse as a refocus pulse, MI3 signal is acquired with their phase difference changed in increments of a fixed angle with each frequency encoding step. This permits the phase difference between an echo signal used for imaging and an FID signal unnecessary for imaging to be changed in increments of the fixed angle with each encoding step. Thus, a zipper artifact based on the FID signal will be produced in a position corresponding to the fixed angle in an MR image reconstructed through Fourier transform of the acquired signal. The proper setting of the fixed angle of the phase difference permits the zipper artifact to be shifted to any position in the MR image.
HIGH TEMPERATURE NMR SAMPLE SPINNER Doty F David; Spitzmesser Jonathan B; Wilson David G Columbia, SC, UNITED STATES Assigned to Doty Scientific Inc A high-strength, thin-wall ceramic cylinder partially closed at one end, with radial-inflow turbine blades ground into the partially closed end thereof, provides the rotational drive, surface protection, and burst strength necessary to contain and spin a low strength, disposable soft ceramic capsule, loaded with a sample for NMR experiments, at high rotational speeds inside an
5334966 MAGNETOSTATIC FIELD GENERATOR FOR MAGNETIC RESONANCE IMAGING APPARATUS Hiroyuki Takeshima Hirotaka, Takeuchi Ryugasaki, JAPAN Assigned to Hitachi Medical carp
New Patents
A magnetostatic field generator for a magnetic resonance imaging apparatus includes a pair of permanent magnets each having a rectangular parallelepiped shape arranged perpendicular to a direction of a uniform magnetic field to surround a space where a uniform magnetic field is generated, a plurality of first permanent magnets each having a trigonal prism shape arranged on both sides of an area between the permanent magnets each having a rectangular parahelepiped shape, a plurality of second permanent magnets each having a uigonal prism shape which are arranged between the permanent magnets each having a rectangular parallelepiped shape and the first permanent magnets and satisfy magnetic field boundary conditions between the permanent magnets each having a rectangular parallelepiped shape and the first permanent magnets, and a yoke for holding the pair of permanent magnets each having a rectangular parallelepiped shape, the plurality of first permanent magnets, and the plurality of second permanent magnets and for forming a magnetic path.
5335660
MAGNETIC RESONANCE METHOD OF MEASURING KIDNEY FILTRATION RATES Dumoulin Charles L BaIlston Lake, NY, UNITED STATES Assigned to General Electric Company A magnetic resonance imaging system employs a sequence of radio frequency pulses and magnetic field gradients to detect and measure the spinrelaxation time of moving blood within a subject. Spin-lattice relaxation times are determined by first inverting longitudinal spin magnetization and then detecting the recovery of this magnetization with a series of detection radio frequency pulses. The inversion pulse is applied to the entire subject, but the detection pulses are applied only to a selection portion of the subject. Blood motion causes the blood in the detection region to be replaced for each detection pulse, thereby increasing the accuracy of the measurement and permitting the use of multiple detection pulses after a single inversion pulse. Invivo application of this invention can be used to assessrenal function in individual kidneys.
5336762
POLYCHELATING AGENTS FOR LMAGE AND SPECTRAL ENHANCEME;;NI’(A&D SPECTRAL Banney David Dallas, TX, UNITED STATES Assigned to Access Pharmaceuticals Inc The present invention includes an imageenhancing agent comprising a biodegradable, water-soluble polymer, synthetic or naturally derived and having repeating hydrophilic monomeric units with amino or hydroxyl groups. This agent also includes chelating agents comprising functional groups bound to an amino or hydroxyl group of the monomeric units. These chelating agents have a formation constant for divalent or trivalent metal cations of at least about 108 at physiological temperature and pH. This image-enhancing agent is biodegradable to intermediary metabolites, excretable chelates, oligomers, monomers or combinations thereof of low toxicity. These image-enhancing agents may further comprise a paramagnetic metal ion for enhancement of the image arising from induced magnetic resonance signals. Images resulting from scanning of gamma particle emissions may be enhanced when the image-enhancing agent of the present invention comprises radioisotopic metal ions emitting gamma particles. The physical conversion of these image-enhancing agents into microspheres (or, less optimally, lirrther internal microaggregates) allows directioning of the image-enhancing agents to organs with phagocytic capabilities. Dextran is a preferred polymer; DTPA and gadolinium are respectively preferred chelating agents and paramagnetic metal ions.
5336988
SCALAR S-PARAMETER TEST SET FOR NMR INSTRUMENTATION MEASUREMENTS Chmielewski Thorn& Molyneaux David; Braum William 0 Highland Heights, OH, UNITED STATES Assigned to Picker International Inc An RF device (A) under test is connected with ports or jacks (14, 16) of an S-parameter test set