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4656425 Method to eliminate the effects of magnetic field inhomogeneities in NMR imaging and apparatus therefor
IV
New Patents
of a high frequency signal capable of use in connection with rotating specific atomic nuclei and/or demodulating resultant magnetic resonance signals. The system includes a memory for storing digital signals which collectively represent the waveform of an analog signal and a mechanism for reading those digital signals from the memory by accessing addresses of the memory at a rate responsive to a frequency control signal to produce a series of digital signals which represent the analog signal having an angular frequency which is a function of the frequency control signal. An offset circuit is provided for offsetting the addresses of the memory means accessed by the reading mechanism in response to the phase control signal. The output of the memory means is used to efficiently and effectively alter the phase and angular frequency of that high frequency signal.
4656026 MAGNETIC RESONANCE (MR) IMAGE ENHANCEMENT COMPOUNDS FOR SPECIFIC AREAS OF THE BRAIN Jeffrey A Coffman, signed to University tion
4656424 APPARATUS AND METHODS FOR SELECTIVE EXCITATION
Charles F Barfknecht asof Iowa Research Founda-
An improved imaging technique involving nuclear magnetic resonance. Known drug or neurotransmitter receptor ligands are covalently bound to magnetic resonance image enhancing spin label compounds, such as sterically hindered free radical nitroxide compounds, with the resulting adduct being administered to a patient, and thereafter when the ligand is bound to specific receptor sites in the soft tissue such as the brain, regional tissue area is assessed with nuclear magnetic resonance, allowing diagnostic discrimination.
4656423
Yuval Tsur, Tomas 31051, Israel
Duby,
Saul Stokar,
Haifa
Arrangements for selectively exciting sections of bodies being imaged in NMR systems wherein the rotating magnetic fields are shaped with envelopes defined by the sum of a sine function and a cosine function.
4656425 METHOD TO ELIMINATE THE EFFECTS OF MAGNETIC FIELD INHOMOGENEITIES IN NMR IMAGING AND APPARATUS THEREFOR Peter Bendel, Rishon Le Zion, Israel assigned Yeda Research and Development Co
NUCLEAR MAGNETIC RESONANCE DIAGNOSTIC APPARATUS Hirosh Sugimoto, Tochigi, Japan assigned Tokyo Shibaura Denki Kabushiki Kaisha
longitudinal axis of the patient. A first coil device is arranged along this longitudinal axis and applies a first gradient magnetic field in conjunction with the static magnetic field so as to define a slice in the patient which is to be examined. The first coil device also applies at least one second gradient magnetic field which defines a projection angle from which NMR signals are obtained. A probe head coil device applies RF pulses to excite nuclei in the slice and to detect the NMR signals emanating from the slice. A second coil device is arranged along the longitudinal axis and applies to the slice a shifting magnetic field which shifts a magnetically-zero plane of the first gradient magnetic field in a direction perpendicular to the magnetically-zero plane. A plurality of second coil means may be provided to shift a magnetically-zero plane throughout the patient so that slices in any portion of the patient may be examined.
to
An NMR diagnostic apparatus capable of obtaining tomographic images in any direction and in any portion of the patient. A magnetic device a static magnetic field along a applies
to
NMR imaging apparatus comprising apparatus for applying a linear magnetic field gradient to a sample, apparatus for varying the magnetic field gradient in a predetermined manner, apparatus for obtaining an NMR signal based on the linear magnetic field gradient, apparatus for storing the NMR signal, apparatus for reconstructing an NMR image from the stored NMR signal, and display apparatus for displaying the
New
reconstructed NMR image, and wherein the apparatus for obtaining an NMR signal includes apparatus for obtaining the NMR signal at times when cancellation of the signal component dependent on magnetic field inhomogeneities occurs. There is also provided a technique for NMR imaging using the above apparatus.
4656426 NUCLEAR MAGNETIC RESONANCE DATA PROCESSING METHOD Noriaki Yamada, Kazuya Hoshino, Tadash Sugiyama, Hiroyuki Matsuura, Tokyo, Japan assigned to Yokogawa Hokushin Electric Corporation; Yokogawa Medical Systems Limite An NMR data processing method for use with an NMR tomograph, wherein signals, located in a period before and after an NMR signal to be sampled and containing substantially none of the NMR signal component, are measured as offset data for each view, so that even the offset slightly fluctuating in the view can be corrected for the NMR signal, on the basis of that data.
4656449 FIELD MODIFYING ELEMENTS FOR AN ELECTROMAGNET HAVING A SUBSTANTIALLY C-SHAPED YOKE J R Mallard, F E Neale, Aberdeen AB2 6BG, United Kingdom An electromagnet having a ferromagnetic core comprising at least one substantially C-shaped yoke terminating in pole pieces (1,2) with opposed pole faces (7) separated by an air gap in which a magnetic field suitable for an NMR imaging process is, in use, produced, the core comprising stacked laminae (6) of electrical sheet steel, which are bent around the C about axes perpendicular to the plane of the C, and at least some of which are spaced apart at the pole pieces to accommodate between the spaced laminae field modifying elements (5,8) which are arranged to improve the homogeneity and/or confinement of the magnetic field in the air gap.
Patents
V
4659348 EXHAUST GAS PARTICLE FILTER FOR INTERNAL COMBUSTION ENGINES Andreas Mayer, Niederrohrdorf, Switzerland assigned to BBC Brown Boveri & Company Limited The exhaust gas particle filter has a parabola shaped recess in the core ensuring that the inlet flow of the exhaust gases is directed towards the central filter part. The latter has a lower degree of separation relative to the outer filter partEl3 caused by increased filter porosity and smaller mass + 13 so that the exhaust gases flow through the central filter part in the initial phase. Its larger filter porosity and the small mass cause the temperature reduction of the exhaust gas flowing through to remain small so that a downstream supercharger can respond rapidly. Since the separation of soot particles initially occurs primarily in the central filter part, rapid deposition occurs + 13 despite its low degree of separation+ 13 so that the resistance during the operation following the acceleration phase becomes similar to that of the surrounding outer filter part. The latter then offers the capacity of separating soot particles over a longer period without regeneration. + RE
4660013 COMPACT WHOLE BODY RESISTIVE MAGNETIC RESONANCE IMAGING MAGNET Evangelos T Laskaris, Madabushi V Chari assigned to General Electric Company A resistive magnet is provided having a cylindrical radio frequency/gradient coil assembly. A first and second cylindrically shaped main coil is situated coaxially on either side of the radio frequency/gradient coil assembly with the radio frequency/gradient coil assembly and the first and second main coils having the same inside diameter defining a magnet bore. A cylindrical correction assembly coil surrounds the radio frequency/gradient coil assembly. Means for securing the first and second main coil to the cylindrical correction assembly is provided. The radio frequency/gradient assembly provides axial support for the first and second main coil assembly. For additional cylindrical main coils surround the correction coil.
New Patents
of a high frequency signal capable of use in connection with rotating specific atomic nuclei and/or demodulating resultant magnetic resonance signals. The system includes a memory for storing digital signals which collectively represent the waveform of an analog signal and a mechanism for reading those digital signals from the memory by accessing addresses of the memory at a rate responsive to a frequency control signal to produce a series of digital signals which represent the analog signal having an angular frequency which is a function of the frequency control signal. An offset circuit is provided for offsetting the addresses of the memory means accessed by the reading mechanism in response to the phase control signal. The output of the memory means is used to efficiently and effectively alter the phase and angular frequency of that high frequency signal.
4656026 MAGNETIC RESONANCE (MR) IMAGE ENHANCEMENT COMPOUNDS FOR SPECIFIC AREAS OF THE BRAIN Jeffrey A Coffman, signed to University tion
4656424 APPARATUS AND METHODS FOR SELECTIVE EXCITATION
Charles F Barfknecht asof Iowa Research Founda-
An improved imaging technique involving nuclear magnetic resonance. Known drug or neurotransmitter receptor ligands are covalently bound to magnetic resonance image enhancing spin label compounds, such as sterically hindered free radical nitroxide compounds, with the resulting adduct being administered to a patient, and thereafter when the ligand is bound to specific receptor sites in the soft tissue such as the brain, regional tissue area is assessed with nuclear magnetic resonance, allowing diagnostic discrimination.
4656423
Yuval Tsur, Tomas 31051, Israel
Duby,
Saul Stokar,
Haifa
Arrangements for selectively exciting sections of bodies being imaged in NMR systems wherein the rotating magnetic fields are shaped with envelopes defined by the sum of a sine function and a cosine function.
4656425 METHOD TO ELIMINATE THE EFFECTS OF MAGNETIC FIELD INHOMOGENEITIES IN NMR IMAGING AND APPARATUS THEREFOR Peter Bendel, Rishon Le Zion, Israel assigned Yeda Research and Development Co
NUCLEAR MAGNETIC RESONANCE DIAGNOSTIC APPARATUS Hirosh Sugimoto, Tochigi, Japan assigned Tokyo Shibaura Denki Kabushiki Kaisha
longitudinal axis of the patient. A first coil device is arranged along this longitudinal axis and applies a first gradient magnetic field in conjunction with the static magnetic field so as to define a slice in the patient which is to be examined. The first coil device also applies at least one second gradient magnetic field which defines a projection angle from which NMR signals are obtained. A probe head coil device applies RF pulses to excite nuclei in the slice and to detect the NMR signals emanating from the slice. A second coil device is arranged along the longitudinal axis and applies to the slice a shifting magnetic field which shifts a magnetically-zero plane of the first gradient magnetic field in a direction perpendicular to the magnetically-zero plane. A plurality of second coil means may be provided to shift a magnetically-zero plane throughout the patient so that slices in any portion of the patient may be examined.
to
An NMR diagnostic apparatus capable of obtaining tomographic images in any direction and in any portion of the patient. A magnetic device a static magnetic field along a applies
to
NMR imaging apparatus comprising apparatus for applying a linear magnetic field gradient to a sample, apparatus for varying the magnetic field gradient in a predetermined manner, apparatus for obtaining an NMR signal based on the linear magnetic field gradient, apparatus for storing the NMR signal, apparatus for reconstructing an NMR image from the stored NMR signal, and display apparatus for displaying the
New
reconstructed NMR image, and wherein the apparatus for obtaining an NMR signal includes apparatus for obtaining the NMR signal at times when cancellation of the signal component dependent on magnetic field inhomogeneities occurs. There is also provided a technique for NMR imaging using the above apparatus.
4656426 NUCLEAR MAGNETIC RESONANCE DATA PROCESSING METHOD Noriaki Yamada, Kazuya Hoshino, Tadash Sugiyama, Hiroyuki Matsuura, Tokyo, Japan assigned to Yokogawa Hokushin Electric Corporation; Yokogawa Medical Systems Limite An NMR data processing method for use with an NMR tomograph, wherein signals, located in a period before and after an NMR signal to be sampled and containing substantially none of the NMR signal component, are measured as offset data for each view, so that even the offset slightly fluctuating in the view can be corrected for the NMR signal, on the basis of that data.
4656449 FIELD MODIFYING ELEMENTS FOR AN ELECTROMAGNET HAVING A SUBSTANTIALLY C-SHAPED YOKE J R Mallard, F E Neale, Aberdeen AB2 6BG, United Kingdom An electromagnet having a ferromagnetic core comprising at least one substantially C-shaped yoke terminating in pole pieces (1,2) with opposed pole faces (7) separated by an air gap in which a magnetic field suitable for an NMR imaging process is, in use, produced, the core comprising stacked laminae (6) of electrical sheet steel, which are bent around the C about axes perpendicular to the plane of the C, and at least some of which are spaced apart at the pole pieces to accommodate between the spaced laminae field modifying elements (5,8) which are arranged to improve the homogeneity and/or confinement of the magnetic field in the air gap.
Patents
V
4659348 EXHAUST GAS PARTICLE FILTER FOR INTERNAL COMBUSTION ENGINES Andreas Mayer, Niederrohrdorf, Switzerland assigned to BBC Brown Boveri & Company Limited The exhaust gas particle filter has a parabola shaped recess in the core ensuring that the inlet flow of the exhaust gases is directed towards the central filter part. The latter has a lower degree of separation relative to the outer filter partEl3 caused by increased filter porosity and smaller mass + 13 so that the exhaust gases flow through the central filter part in the initial phase. Its larger filter porosity and the small mass cause the temperature reduction of the exhaust gas flowing through to remain small so that a downstream supercharger can respond rapidly. Since the separation of soot particles initially occurs primarily in the central filter part, rapid deposition occurs + 13 despite its low degree of separation+ 13 so that the resistance during the operation following the acceleration phase becomes similar to that of the surrounding outer filter part. The latter then offers the capacity of separating soot particles over a longer period without regeneration. + RE
4660013 COMPACT WHOLE BODY RESISTIVE MAGNETIC RESONANCE IMAGING MAGNET Evangelos T Laskaris, Madabushi V Chari assigned to General Electric Company A resistive magnet is provided having a cylindrical radio frequency/gradient coil assembly. A first and second cylindrically shaped main coil is situated coaxially on either side of the radio frequency/gradient coil assembly with the radio frequency/gradient coil assembly and the first and second main coils having the same inside diameter defining a magnet bore. A cylindrical correction assembly coil surrounds the radio frequency/gradient coil assembly. Means for securing the first and second main coil to the cylindrical correction assembly is provided. The radio frequency/gradient assembly provides axial support for the first and second main coil assembly. For additional cylindrical main coils surround the correction coil.