- Email: [email protected]
5035231 Endoscope apparatus
IV
New Patents
sleeve defines a circumferentially extending rabbet on either end of the sleeve on the inner diameter. The edge of the outer diameter of each coil is secured in one of the rabbets in the sleeve.
5034691 MAGNETIC RESONANCE METHODS AND APPARATUS Ian R Young, Nr Marlborough, United Kingdom assigned to Picker International Ltd A magnetic resonance method comprising the steps of exciting magnetic resonance in nuclei in a planar region of a body, applying a first gradient magnetic field having a periodically reversing gradient in a first direction across the region in conjunction with a series of pulses of a second gradient magnetic field in a second direction across the region orthogonal to the first direction, progressively decreasing the time between successive pulses of the second gradient, sensing resonance signals from the nuclei, and subjecting the resonance signals to a two-dimensional Fourier Transform process to acquire data relating to the region of the body. In the method the time between successive pulses of the second gradient is decreased in such a manner as to avoid acquisition of data in respect of areas in the corners of a rectangular matrix defined by the first and second gradient fields. Also, in the method the time between successive reversals of the gradient of the first gradient field is caused to vary in corresponding manner to the time between successive pulses of the second gradient field.
5034692 MAGNETIC RESONANCE IMAGING METHOD FOR ACQUIRING FLUXCOMPENSATED, TZWEIGHTED IMAGES Gerhard Laub, Michael Deimling, Heroldsbach, Federal Republic Of Germany assigned to Siemens Aktiengesellschaft A method for obtaining an image in a magnetic resonance imaging apparatus uses a steady state pulse sequence which is based on a combination of a FISP pulse sequence and a PSIF pulse sequence. To signals are obtained by executing a sequence of steps once with alternating phase relation of the RF pulses, which excite the
nuclear spins, and once with non-altering phase relation. By subtracting these signals, a pure PSIF signal is obtained, and the steady state is not disturbed by the moving spins. The flux phase is also compensated by the additional introduction of gradient motion refocusing (GMR) pulses, so that images of pulsating examination subjects, such as cerebral spin fluid, can be obtained free of flux artifacts.
5034694 MINIMUM BASIS SET MR ANGIOGRAPHY Willia Sattin, Larry Kasuboski, Wayne R Dannels, Cleveland Hts, OH, United Statee assigned to Picker International Inc A radio frequency pulse (32), a gradient pulse (34), and a first frequency offset pulse (38a) are applied to cause the presaturation region (36a) adjacent one face of an imaging volume (30) such that material flowing into the imaging volume from that face is saturated. An imaging sequence is applied which generates magnetic resonance image data that has non-saturated flow in the imaging volume identified by a characteristic phase modulated intensity. The saturation and gradient pulses are applied again with a second frequency offset pulse (38b) to position the saturation region (36b) adjacent the opposite face of the image volume. The exact same imaging sequence is applied to generate a second set of image data in which non-saturated flowing material is identified by a characteristic phase modulated intensity. Magnitude values from these two data sets are reconstructed (72,74) into image representations that are subtractively combined (76), to form a difference image representation. In the difference image representation, the static material has essentially a zero value, flowing material that entered from one face is strictly positive, and flowing material that entered from the other face is strictly negative. In this manner, two different flowing materials, such as venous and arterial blood, are separately encoded in only two imaging sequences.
5035231 ENDOSCOPE
APPARATUS
Hiroaki Kubokawa, Takashi Tsukaya, Yasuhiro Ueda, Yutaka Ohshima, Takeaki Nakamura, Hiroki Hibino, Shuichi Takayama, Tadao Hagino, Hachioji, Japan assigned to Olympus Optical Co Ltd
New Patents
This endoscope apparatus adapted to meter NMR (nuclear magnetic resonance) is provided with an endoscope having a channel and an NMR metering probe insertable through the channel. The endoscope has an elongate insertable part having an observing window and illuminating window in the tip part, an observing system for observing an object to be imaged by receiving a light from the object entering through the observing window, an illuminating light output system emitting an illuminating light through the illuminating window and a hollow channel formed within the insertable part and opening in the tip part. Preferably, at least the tip side of the insertable part if formed of a nonferromagnetic characteristic material. The NMR metering probe has a signal transmitting member insertable through the channel of the endoscope, connected at one end to the NMR metering apparatus and able to transmit high frequency signals and a loop-like antenna part connected to the other end of the signal transmitting member and projected out of the opening of the channel.
V
5036280 PHANTOM FOR MAGNETIC RESONANCE IMAGING SYSTEM Jay A Chesavage assigned to MRI Technologies A cylindrical tube with closed ends contains an imaging fluid and a variety of imaging structures enclosed. Included is a slice thickness structure with a hole pattern in a chevron shape where the number of imaged holes determines the slice thickness. Slice planarity is determined by a number of contiguous disks with grooved patterns set at rotated angles with respect to each other. Geometric distortion and resolution are also measured by structures contained within the enclosure. Finally, the position of the first and last slices in a multiscan series is measured for accuracy by ramp wedges placed on the end caps of the enclosure. And lastly, air is entrapped in closed cell foam so there are no unconstrained bubbles migrating in the enclosure.
5036282 5035244 MOTION ARTIFACT MINIMIZATION
BIPLANAR GRADIENT COIL FOR MAGNETIC RESONANCE IMAGING SYSTEMS
Saul Stokar, Raanana, Israel assigned to Elscint Ltd
Michael A Morich, Michael A Martens, Robert W Brown assigned to Picker International Inc
A method for reducing respiratory motion caused artifacts in magnetic resonance imaging. The respiration cycle amplitude of the patient is divided into a plurality of intervals. Each interval is assigned a preferred encoding pulse. If the preferred encoding pulse has been used the next sequential (higher or lower) unused phase encoding pulse of a valve that is +/-SO% of the originally preferred phase encoding pulse is used.
A planar gradient magnetic field assembly (20) selectively causes gradient magnetic fields linearly across the examination region (12) of a magnetic resonance imaging apparatus. The gradient coil assembly includes a pair of planar y gradient coils (22a, 22b) and a pair of planar x gradient coils (24a, 24b). On each plane, the gradient coil winding includes a pair of larger, outer coil loop arrays (60, 62). A pair of smaller inner coil loop arrays (66, 68) produce a first order gradient field correction to improve the accuracy of the gradient field. The coil loop arrays are symmetric relative to the z axis and relative to an (x,y) plane of symmetry perpendicular to the z axis.
5036279 PORTABLE NMR AND NQR SPECTROMETERS Paul Jonsen, London, United Kingdom assigned to Datalight Limited A NMR/NQR spectrometer incorporating a superconducting quantum interference device (SQUID) made from mixed oxides of a lanthanide, copper and barium.
5036426 METHOD AND APPARATUS FOR TUNING AND MATCHING AN NMR COIL Gary G Shen assigned to Board of Regents The University of Texas System
New Patents
sleeve defines a circumferentially extending rabbet on either end of the sleeve on the inner diameter. The edge of the outer diameter of each coil is secured in one of the rabbets in the sleeve.
5034691 MAGNETIC RESONANCE METHODS AND APPARATUS Ian R Young, Nr Marlborough, United Kingdom assigned to Picker International Ltd A magnetic resonance method comprising the steps of exciting magnetic resonance in nuclei in a planar region of a body, applying a first gradient magnetic field having a periodically reversing gradient in a first direction across the region in conjunction with a series of pulses of a second gradient magnetic field in a second direction across the region orthogonal to the first direction, progressively decreasing the time between successive pulses of the second gradient, sensing resonance signals from the nuclei, and subjecting the resonance signals to a two-dimensional Fourier Transform process to acquire data relating to the region of the body. In the method the time between successive pulses of the second gradient is decreased in such a manner as to avoid acquisition of data in respect of areas in the corners of a rectangular matrix defined by the first and second gradient fields. Also, in the method the time between successive reversals of the gradient of the first gradient field is caused to vary in corresponding manner to the time between successive pulses of the second gradient field.
5034692 MAGNETIC RESONANCE IMAGING METHOD FOR ACQUIRING FLUXCOMPENSATED, TZWEIGHTED IMAGES Gerhard Laub, Michael Deimling, Heroldsbach, Federal Republic Of Germany assigned to Siemens Aktiengesellschaft A method for obtaining an image in a magnetic resonance imaging apparatus uses a steady state pulse sequence which is based on a combination of a FISP pulse sequence and a PSIF pulse sequence. To signals are obtained by executing a sequence of steps once with alternating phase relation of the RF pulses, which excite the
nuclear spins, and once with non-altering phase relation. By subtracting these signals, a pure PSIF signal is obtained, and the steady state is not disturbed by the moving spins. The flux phase is also compensated by the additional introduction of gradient motion refocusing (GMR) pulses, so that images of pulsating examination subjects, such as cerebral spin fluid, can be obtained free of flux artifacts.
5034694 MINIMUM BASIS SET MR ANGIOGRAPHY Willia Sattin, Larry Kasuboski, Wayne R Dannels, Cleveland Hts, OH, United Statee assigned to Picker International Inc A radio frequency pulse (32), a gradient pulse (34), and a first frequency offset pulse (38a) are applied to cause the presaturation region (36a) adjacent one face of an imaging volume (30) such that material flowing into the imaging volume from that face is saturated. An imaging sequence is applied which generates magnetic resonance image data that has non-saturated flow in the imaging volume identified by a characteristic phase modulated intensity. The saturation and gradient pulses are applied again with a second frequency offset pulse (38b) to position the saturation region (36b) adjacent the opposite face of the image volume. The exact same imaging sequence is applied to generate a second set of image data in which non-saturated flowing material is identified by a characteristic phase modulated intensity. Magnitude values from these two data sets are reconstructed (72,74) into image representations that are subtractively combined (76), to form a difference image representation. In the difference image representation, the static material has essentially a zero value, flowing material that entered from one face is strictly positive, and flowing material that entered from the other face is strictly negative. In this manner, two different flowing materials, such as venous and arterial blood, are separately encoded in only two imaging sequences.
5035231 ENDOSCOPE
APPARATUS
Hiroaki Kubokawa, Takashi Tsukaya, Yasuhiro Ueda, Yutaka Ohshima, Takeaki Nakamura, Hiroki Hibino, Shuichi Takayama, Tadao Hagino, Hachioji, Japan assigned to Olympus Optical Co Ltd
New Patents
This endoscope apparatus adapted to meter NMR (nuclear magnetic resonance) is provided with an endoscope having a channel and an NMR metering probe insertable through the channel. The endoscope has an elongate insertable part having an observing window and illuminating window in the tip part, an observing system for observing an object to be imaged by receiving a light from the object entering through the observing window, an illuminating light output system emitting an illuminating light through the illuminating window and a hollow channel formed within the insertable part and opening in the tip part. Preferably, at least the tip side of the insertable part if formed of a nonferromagnetic characteristic material. The NMR metering probe has a signal transmitting member insertable through the channel of the endoscope, connected at one end to the NMR metering apparatus and able to transmit high frequency signals and a loop-like antenna part connected to the other end of the signal transmitting member and projected out of the opening of the channel.
V
5036280 PHANTOM FOR MAGNETIC RESONANCE IMAGING SYSTEM Jay A Chesavage assigned to MRI Technologies A cylindrical tube with closed ends contains an imaging fluid and a variety of imaging structures enclosed. Included is a slice thickness structure with a hole pattern in a chevron shape where the number of imaged holes determines the slice thickness. Slice planarity is determined by a number of contiguous disks with grooved patterns set at rotated angles with respect to each other. Geometric distortion and resolution are also measured by structures contained within the enclosure. Finally, the position of the first and last slices in a multiscan series is measured for accuracy by ramp wedges placed on the end caps of the enclosure. And lastly, air is entrapped in closed cell foam so there are no unconstrained bubbles migrating in the enclosure.
5036282 5035244 MOTION ARTIFACT MINIMIZATION
BIPLANAR GRADIENT COIL FOR MAGNETIC RESONANCE IMAGING SYSTEMS
Saul Stokar, Raanana, Israel assigned to Elscint Ltd
Michael A Morich, Michael A Martens, Robert W Brown assigned to Picker International Inc
A method for reducing respiratory motion caused artifacts in magnetic resonance imaging. The respiration cycle amplitude of the patient is divided into a plurality of intervals. Each interval is assigned a preferred encoding pulse. If the preferred encoding pulse has been used the next sequential (higher or lower) unused phase encoding pulse of a valve that is +/-SO% of the originally preferred phase encoding pulse is used.
A planar gradient magnetic field assembly (20) selectively causes gradient magnetic fields linearly across the examination region (12) of a magnetic resonance imaging apparatus. The gradient coil assembly includes a pair of planar y gradient coils (22a, 22b) and a pair of planar x gradient coils (24a, 24b). On each plane, the gradient coil winding includes a pair of larger, outer coil loop arrays (60, 62). A pair of smaller inner coil loop arrays (66, 68) produce a first order gradient field correction to improve the accuracy of the gradient field. The coil loop arrays are symmetric relative to the z axis and relative to an (x,y) plane of symmetry perpendicular to the z axis.
5036279 PORTABLE NMR AND NQR SPECTROMETERS Paul Jonsen, London, United Kingdom assigned to Datalight Limited A NMR/NQR spectrometer incorporating a superconducting quantum interference device (SQUID) made from mixed oxides of a lanthanide, copper and barium.
5036426 METHOD AND APPARATUS FOR TUNING AND MATCHING AN NMR COIL Gary G Shen assigned to Board of Regents The University of Texas System