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5235283 Gradient coil system for a nuclear magnetic resonance tomography apparatus which reduces acoustic noise
IX
New Patents
resonant type amplifier or a current type inverter for outputting a first current of a given waveform, a linear type transconductance amplifier for outputting a second current of an arbitrary waveform at a lower level than that of the first current, a gradient field coil having first and second windings for respectively running the first and second currents, the first and second windings being wound in a bifilar form, and a cancel coil for canceling a voltage induced by the gradient field coil, the cancel coil having third and fourth windings for respectively connected between the first winding and the resonant type amplifier or a current type inverter and between the second winding and the linear type transconductance amplifier, the third and fourth windings being wound in a bifilar form.
5235282 MAGNETIC RESONANCE APPARATUS COMPRISING A SUPERCONDUCTING SHIELDING MAGNET Johannes A Overweg, Gerardus N Peeren, Eindhoven, Netherlands assigned to U S Philips Corporation In a magnetic resonance apparatus comprising a superconducting magnet system (1) for generating a steady magnetic field there is also included a superconducting shielding coil system (22) in order to compensate for magnetic field variations induced in the magnet by external magnetic flux variations. The shielding coil system (22) comprises coil sections (24) of different diameters.
5235283 GRADIENT COIL SYSTEM FOR A NUCLEAR MAGNETIC RESONANCE TOMOGRAPHY APPARATUS WHICH REDUCES ACOUSTIC NOISE Dietmar Lehne, Guenter Theil, Guenther Pausch, Wolfgang Rogler, Poxdorf, Federal Republic Of Germany assigned to Siemens Aktiengesellschaft
The supply of current pulses to gradient coils in a magnetic resonance imaging tomography apparatus results in physical vibration of the coils, causing acoustic noise. For reducing such acoustic noise, a gradient coil system is disclosed wherein the individual gradient coils are secured on a tubular carrier formed by a two concentric shells. The two shells are joined to each other in a manner which is rigid against shearing in the longitudinal direction by connector elements. The self-excited vibrational behavior of the gradient coil system is thereby tuned to lower vibrational amplitudes and to higher vibrational frequencies, so that a more effective damping can be achieved with acoustic damping measures.
PASSIVE SHIM ARRANGEMENT FOR NUCLEAR MAGNETIC RESONANCE Yasuyuki Tahara, Keiichi Ebihara, Naoji Yoshida, Kazuak Takeuchi, Ako, Japan assigned to Mitsubishi Denki Kabushiki Kaisha A passive shim arrangement for a nuclear magnetic resonance apparatus has a plurality of nonmagnetic tubes disposed at predetermined positions around a common axis. Each tube is parallel to and uniformly distant from the axis. Magnetic shims are inserted into the tubes to correct components of the magnetic field.
5236694 19F LABELLED DEXTRANS AND ANTIBODIES AS NMR IMAGING AND SPECTROSCOPY AGENTS Peter P Antich, Padmakar V Kulkarni assigned to The Board of Regents The University of Texas System 19F labelled compounds are disclosed which are useful in methods of NMR imaging and spectroscopy. The compounds comprise a 19Fcontaining sensor moiety, and a transport polymer or substrate, and can optionally also comprise a spacer moiety to separate the sensor moiety and the transport polymer.
New Patents
resonant type amplifier or a current type inverter for outputting a first current of a given waveform, a linear type transconductance amplifier for outputting a second current of an arbitrary waveform at a lower level than that of the first current, a gradient field coil having first and second windings for respectively running the first and second currents, the first and second windings being wound in a bifilar form, and a cancel coil for canceling a voltage induced by the gradient field coil, the cancel coil having third and fourth windings for respectively connected between the first winding and the resonant type amplifier or a current type inverter and between the second winding and the linear type transconductance amplifier, the third and fourth windings being wound in a bifilar form.
5235282 MAGNETIC RESONANCE APPARATUS COMPRISING A SUPERCONDUCTING SHIELDING MAGNET Johannes A Overweg, Gerardus N Peeren, Eindhoven, Netherlands assigned to U S Philips Corporation In a magnetic resonance apparatus comprising a superconducting magnet system (1) for generating a steady magnetic field there is also included a superconducting shielding coil system (22) in order to compensate for magnetic field variations induced in the magnet by external magnetic flux variations. The shielding coil system (22) comprises coil sections (24) of different diameters.
5235283 GRADIENT COIL SYSTEM FOR A NUCLEAR MAGNETIC RESONANCE TOMOGRAPHY APPARATUS WHICH REDUCES ACOUSTIC NOISE Dietmar Lehne, Guenter Theil, Guenther Pausch, Wolfgang Rogler, Poxdorf, Federal Republic Of Germany assigned to Siemens Aktiengesellschaft
The supply of current pulses to gradient coils in a magnetic resonance imaging tomography apparatus results in physical vibration of the coils, causing acoustic noise. For reducing such acoustic noise, a gradient coil system is disclosed wherein the individual gradient coils are secured on a tubular carrier formed by a two concentric shells. The two shells are joined to each other in a manner which is rigid against shearing in the longitudinal direction by connector elements. The self-excited vibrational behavior of the gradient coil system is thereby tuned to lower vibrational amplitudes and to higher vibrational frequencies, so that a more effective damping can be achieved with acoustic damping measures.
PASSIVE SHIM ARRANGEMENT FOR NUCLEAR MAGNETIC RESONANCE Yasuyuki Tahara, Keiichi Ebihara, Naoji Yoshida, Kazuak Takeuchi, Ako, Japan assigned to Mitsubishi Denki Kabushiki Kaisha A passive shim arrangement for a nuclear magnetic resonance apparatus has a plurality of nonmagnetic tubes disposed at predetermined positions around a common axis. Each tube is parallel to and uniformly distant from the axis. Magnetic shims are inserted into the tubes to correct components of the magnetic field.
5236694 19F LABELLED DEXTRANS AND ANTIBODIES AS NMR IMAGING AND SPECTROSCOPY AGENTS Peter P Antich, Padmakar V Kulkarni assigned to The Board of Regents The University of Texas System 19F labelled compounds are disclosed which are useful in methods of NMR imaging and spectroscopy. The compounds comprise a 19Fcontaining sensor moiety, and a transport polymer or substrate, and can optionally also comprise a spacer moiety to separate the sensor moiety and the transport polymer.