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4755755 Compact transverse magnetic gradient coils and dimensioning method therefor
Magnetic Resonance Imaging, Vol. 7, pp. I-X, 1989 Printed in the USA. All rights reserved.
073&725X/89 $3.00 + .oo 0 1989 Pergamon Press plc
Copyright
NEW PATENTS This Section contains abstracts and, where appropriate, illustrations of recently issued United States patents and published patent applications filed from over 30 countries under the Patent Cooperation Treaty. This information was obtained from recent additions to the Pergamon PATSEARCH@ online database in accordance with interest profiles developed by the Editors. Further information about Pergamon PATSEARCH@ can be obtained from Pergamon Orbit InfoLine Inc., 8000 Westpark Drive, McLean, Virginia 22102 U.S.A. Copies of complete patents announced in this Section are available from Pergamon Orbit InfoLine Inc. for $8 oer CODY. Payment with order is reouired. Orders outside North America add $2 for air postage. Order by patent number for Pergamon Orbit InfoLine only.
in a particular
4732712 STEAM
INJECTION HEATER
fashion-broadly
particle size distribution.
WATER
Gregor Burnham, Jack Kahrs, Anthony
useful in aqueous slurry opacifying fillers for paper.
T Pos-
apparatus by a steam supply conduit which sup-
plies steam to the water supply conduit at a predetermined location between the water inlet end and the water outlet end of the water supply conduit. The steam entering the water supply conduit is controlled by a steam supply control valve located on the steam supply conduit. A pressure differential sensing means senses the difference in pressure along the water supply conduit between a first point in said water supply conduit, upstream of said predetermined location and a second point in the water supply conduit downstream of the predetermined location. A means for controlling the control valve means in response to this sensed pressure differential is also required.
or dry
form
as
4755755
luszny assigned to Leslie Controls Inc An apparatus for controlling the temperature of a supply of water by selective injection of steam is disclosed. The apparatus comprises a water supply conduit which includes a water inlet end and a water outlet end. Steam is supplied to the
stated: in fine
Such compositions are
COMPACT TRANSVERSE MAGNETIC GRADIENT COILS AND DIMENSIONING METHOD THEREFOR Joseph Carlson assigned to The Regents of the University of California
The axial dimensions of the usual saddle coils used to create transverse magnetic gradients in the static magnetic field of a magnetic resonance imaging system are substantially foreshortened. The outer arc of the saddle coil is moved axially inward while still leaving it at a position which
produces negligible net transverse gradient contribution. While this new position of the outer arc can be expected to produce a significant second (third) derivative of the transverse gradient with respect to Z (the orientation of the static magnetic field) at the predetermined ob-
servation point, the inner arc of the saddle coil may .be moved slightly away from the observa-
4732748 FINELY DIVIDED CALCIUM CARBONATE COMPOSITIONS Robert Stewart, Norman 0 Clark, Yew C Chang assigned to Cyprus Mines Corporation Finely divided, wet-ground, dispersant-free calcium carbonate filler or pigment compositions are disclosed in which the particles of calcium carbonate are distributed in particular amounts
tion point so as to produce a second (third) derivative which substantially cancels that of the relocated outer arc. In this manner, the desired condition of having a net zero second (third) derivative may still be maintained even though the axial dimension of the saddle coil has been substantially reduced (e.g., to about 44% of the traditional axial length in one exemplary embodiment). Such a more compact coil may permit realization of lowered inductance (and thus permit
faster gradient
switching
during
MRI
procedures) or, additional coil turns may be employed while still retaining the same inductance
II
New
but thus permitting the regeneration of larger gradients or, the use of lower currents (thereby saving on power amplifiers, power dissipation, etc.).
4755756 RADIO FREQUENCY COIL FOR NUCLEAR MAGNETIC RESONANCE IMAGING Susum Nishihara, Kiyoshi Yoda, Amagasaki, Japan assigned to Mitsubishi Denki Kabushiki Kaisha A radio frequency coil for nuclear magnetic resonance imaging comprises at least one pair of arcuate H-shaped members which are disposed about a longitudinal axis so as to form a tube. A variable capacitor means for adjusting the resonant frequency of the coil is connected across the feeding points of the coil. A balanced feed circuit comprising a balanced impedance matching circuit and a balanced-to-unbalanced converter is connected across the feeding points. An unbalanced current from a transceiver is converted into balanced currents which are fed to the feeding points.
4757260 METHOD OF PRODUCING NUCLEAR MAGNETIC RESONANCE OF AN OBJECT ANDANAPPARATUSTHEREFOR Munetaka Tsuda, Kazutoshi Higuchi, Japan assigned to Hitachi Ltd
A circularly polarized radio frequency probe for use in magnetic resonance systems, the probe comprises four effective saddle coils arranged to define a single cylinder. The saddle coils each comprise a pair of 120 degree arcuate conductor sectors separated by longitudinal conductors. RF power is coupled to each of said saddle coils so that first and second pairs of said saddle coils generate first and second fields normal to each other.
4758422 FERRIOXAMINE PARAMAGNETIC CONTRAST AGENTS FOR MR IMAGING Steven Quay assigned to Salutar Inc In the NMR imaging of a subject comprising administering to such subject a composition containing an image-modifying effective amount of an image enhancer, permitting the enhancer to move through the subject, and after a time interval taking an NMR image of the subject, the improvement which comprises employing as said enhancer a complex of an oxamine and a polyvalent paramagnetic metal, e.g. ferrioxamine. Novel complexes of trihydroxamic acids, optionally N-acylated, with polyvalent metals other than iron, are also described.
4758813
Mito,
A plurality of selective radio frequency pi pulses are applied to an object placed in a static magnetic field which has a magnetic field gradient, to select a plurality of slices of the object corresponding to these pulses. Nuclear magnetic resonance signals are generated from the slices in a manner that a time interval between the selection of slice and the generation of nuclear magnetic resonance signal remains substantially constant for all of the slices.
4757290 HYBRID
Patents
RESONATOR
Hannan Keren, Kfar Saba, Israel assigned to Elscint Ltd
CYLINDRICAL NMR BIAS MAGNET APPARATUS EMPLOYING PERMANENT MAGNETS AND METHODS THEREFOR Ronald F Holsinger, Robert L Gluckstern, John C Fisher assigned to Field Effects Inc NMR bias magnet apparatus employing permanent magnets and methods therefor are provided in accordance with the teachings of the present invention. According to the present invention a plurality of insulating sleeves which may be rotated are disposed about the periphery of a structure having a curvilinear cross section such as a cylinder. Each of the plurality of insulating sleeves are filled with stacks of slabs of permanent magnet material forming slugs and having an anisotropic axis of magnetic orientation aligned at an azimuth corresponding to a = 2 phi. The length of slug sections or even of individual slabs within each sleeve may be varied for pur-
073&725X/89 $3.00 + .oo 0 1989 Pergamon Press plc
Copyright
NEW PATENTS This Section contains abstracts and, where appropriate, illustrations of recently issued United States patents and published patent applications filed from over 30 countries under the Patent Cooperation Treaty. This information was obtained from recent additions to the Pergamon PATSEARCH@ online database in accordance with interest profiles developed by the Editors. Further information about Pergamon PATSEARCH@ can be obtained from Pergamon Orbit InfoLine Inc., 8000 Westpark Drive, McLean, Virginia 22102 U.S.A. Copies of complete patents announced in this Section are available from Pergamon Orbit InfoLine Inc. for $8 oer CODY. Payment with order is reouired. Orders outside North America add $2 for air postage. Order by patent number for Pergamon Orbit InfoLine only.
in a particular
4732712 STEAM
INJECTION HEATER
fashion-broadly
particle size distribution.
WATER
Gregor Burnham, Jack Kahrs, Anthony
useful in aqueous slurry opacifying fillers for paper.
T Pos-
apparatus by a steam supply conduit which sup-
plies steam to the water supply conduit at a predetermined location between the water inlet end and the water outlet end of the water supply conduit. The steam entering the water supply conduit is controlled by a steam supply control valve located on the steam supply conduit. A pressure differential sensing means senses the difference in pressure along the water supply conduit between a first point in said water supply conduit, upstream of said predetermined location and a second point in the water supply conduit downstream of the predetermined location. A means for controlling the control valve means in response to this sensed pressure differential is also required.
or dry
form
as
4755755
luszny assigned to Leslie Controls Inc An apparatus for controlling the temperature of a supply of water by selective injection of steam is disclosed. The apparatus comprises a water supply conduit which includes a water inlet end and a water outlet end. Steam is supplied to the
stated: in fine
Such compositions are
COMPACT TRANSVERSE MAGNETIC GRADIENT COILS AND DIMENSIONING METHOD THEREFOR Joseph Carlson assigned to The Regents of the University of California
The axial dimensions of the usual saddle coils used to create transverse magnetic gradients in the static magnetic field of a magnetic resonance imaging system are substantially foreshortened. The outer arc of the saddle coil is moved axially inward while still leaving it at a position which
produces negligible net transverse gradient contribution. While this new position of the outer arc can be expected to produce a significant second (third) derivative of the transverse gradient with respect to Z (the orientation of the static magnetic field) at the predetermined ob-
servation point, the inner arc of the saddle coil may .be moved slightly away from the observa-
4732748 FINELY DIVIDED CALCIUM CARBONATE COMPOSITIONS Robert Stewart, Norman 0 Clark, Yew C Chang assigned to Cyprus Mines Corporation Finely divided, wet-ground, dispersant-free calcium carbonate filler or pigment compositions are disclosed in which the particles of calcium carbonate are distributed in particular amounts
tion point so as to produce a second (third) derivative which substantially cancels that of the relocated outer arc. In this manner, the desired condition of having a net zero second (third) derivative may still be maintained even though the axial dimension of the saddle coil has been substantially reduced (e.g., to about 44% of the traditional axial length in one exemplary embodiment). Such a more compact coil may permit realization of lowered inductance (and thus permit
faster gradient
switching
during
MRI
procedures) or, additional coil turns may be employed while still retaining the same inductance
II
New
but thus permitting the regeneration of larger gradients or, the use of lower currents (thereby saving on power amplifiers, power dissipation, etc.).
4755756 RADIO FREQUENCY COIL FOR NUCLEAR MAGNETIC RESONANCE IMAGING Susum Nishihara, Kiyoshi Yoda, Amagasaki, Japan assigned to Mitsubishi Denki Kabushiki Kaisha A radio frequency coil for nuclear magnetic resonance imaging comprises at least one pair of arcuate H-shaped members which are disposed about a longitudinal axis so as to form a tube. A variable capacitor means for adjusting the resonant frequency of the coil is connected across the feeding points of the coil. A balanced feed circuit comprising a balanced impedance matching circuit and a balanced-to-unbalanced converter is connected across the feeding points. An unbalanced current from a transceiver is converted into balanced currents which are fed to the feeding points.
4757260 METHOD OF PRODUCING NUCLEAR MAGNETIC RESONANCE OF AN OBJECT ANDANAPPARATUSTHEREFOR Munetaka Tsuda, Kazutoshi Higuchi, Japan assigned to Hitachi Ltd
A circularly polarized radio frequency probe for use in magnetic resonance systems, the probe comprises four effective saddle coils arranged to define a single cylinder. The saddle coils each comprise a pair of 120 degree arcuate conductor sectors separated by longitudinal conductors. RF power is coupled to each of said saddle coils so that first and second pairs of said saddle coils generate first and second fields normal to each other.
4758422 FERRIOXAMINE PARAMAGNETIC CONTRAST AGENTS FOR MR IMAGING Steven Quay assigned to Salutar Inc In the NMR imaging of a subject comprising administering to such subject a composition containing an image-modifying effective amount of an image enhancer, permitting the enhancer to move through the subject, and after a time interval taking an NMR image of the subject, the improvement which comprises employing as said enhancer a complex of an oxamine and a polyvalent paramagnetic metal, e.g. ferrioxamine. Novel complexes of trihydroxamic acids, optionally N-acylated, with polyvalent metals other than iron, are also described.
4758813
Mito,
A plurality of selective radio frequency pi pulses are applied to an object placed in a static magnetic field which has a magnetic field gradient, to select a plurality of slices of the object corresponding to these pulses. Nuclear magnetic resonance signals are generated from the slices in a manner that a time interval between the selection of slice and the generation of nuclear magnetic resonance signal remains substantially constant for all of the slices.
4757290 HYBRID
Patents
RESONATOR
Hannan Keren, Kfar Saba, Israel assigned to Elscint Ltd
CYLINDRICAL NMR BIAS MAGNET APPARATUS EMPLOYING PERMANENT MAGNETS AND METHODS THEREFOR Ronald F Holsinger, Robert L Gluckstern, John C Fisher assigned to Field Effects Inc NMR bias magnet apparatus employing permanent magnets and methods therefor are provided in accordance with the teachings of the present invention. According to the present invention a plurality of insulating sleeves which may be rotated are disposed about the periphery of a structure having a curvilinear cross section such as a cylinder. Each of the plurality of insulating sleeves are filled with stacks of slabs of permanent magnet material forming slugs and having an anisotropic axis of magnetic orientation aligned at an azimuth corresponding to a = 2 phi. The length of slug sections or even of individual slabs within each sleeve may be varied for pur-