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5023551 Nuclear magnetic resonance pulse sequences for use with borehole logging tools
New Patents
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angiogram using a single echo method. If the view angle of each echo is the same, then the acquired angiograms can be added to enhance the signal-to-noise ratio. Another pulse sequence simultaneously obtains two or more angiograms, each sensitive to one of two orthogonal flow components of the overall blood flow; the angiograms are then added to give an angiogram which is sensitive to total flow in all directions. Multiple velocity ranges are accommodated in a fourth sequence form.
5022405 STETHOSCOPE FOR USE IN NUCLEAR MAGNETIC RESONANCE DIAGNOSTICS J Bertil Hok, Valerie Bythell, Vs, Sweded assigned to Hok Instrument AB A stethoscope for use with nuclear magnetic resonance (NMR) screenings in order to supervise a patient, including a bell chest piece adapted to pick up audible heart and breathing sounds or other bodily sounds from the patient, a flexible hollow tube connected at one end thereof to the bell chest piece and adapted to transmit audible heart and breathing sounds from the bell chest piece. The novel features of the invention are, a microphone member adapted to be arranged at the opposite side the tube outside the zone of the maximum field strength of the NMR equipment and adapted to convert the acoustic signals into corresponding electrical signals, an optical transmitter to which the microphone member is connected and from which optical signals are transmitted to the surrounding in at least one direction, the optical signals corresponding to the electrical signals, and at least one receiver for receiving the optical signals from the optical transmitter and for converting the optical signals into electrical signals corresponding to said audible sounds.
5023072 PARAMAGNETIC SUPERPARAMAGNETIC FERROMAGNETIC SUCROSE SULFATE COMPOSITIONS FOR MAGNETIC RESONANCE IMAGING OF THE GASTROINTESTINAL TRACT Kenneth T Cheng assigned to University of New Mexico
The disclosure is directed to a sucrose sulfate composition useful for magnetic resonance imaging of the gastrointestinal tract. Paraferromagnetic magnetic/superparamagnetic ions or particles are attached to sucrose sulfate molecules in the composition. The sucrose sulfate composition travels, in the patient, to sites in the gastrointestinal tract which are diseased and ferthe paramagnetic/superparamagnetic romagnetic ions or particles allow magnetic resonance imaging to be more effective for imaging of these sites in the gastrointestinal tract.
5023185 METHOD FOR DETERMINING RESOLUTION POWER OR DISCRIMINATION CAPACITY OF AN NMR IMAGING APPARATUS Masao Nambu, Naoaki Yamada, Yokohama, Japan assigned to Nippon Oil Co Ltd A phantom for diagnosis by nuclear magnetic resonance imaging comprises a container made of a synthetic resin and a hydrogel sealingly contained in the container. The container has at least one opening into which a sample material is inserted. The hydrogel is prepared by charging an aqueous solution of a polyvinyl alcohol into the container, cooling the aqueous solution to minus 10 degreesc. or lower to obtain a cooled frozen mass and thawing the cooled frozen mass. Also disclosed is a method for determining resolution power or discrimination capacity of an NMR imaging apparatus.
5023551 NUCLEAR MAGNETIC RESONANCE PULSE SEQUENCES FOR USE WITH BOREHOLE LOGGING TOOLS Robert L Kleinberg, Abdurrahman Sezginer, Masafumi Fukuhara assigned to SchlumbergerDoll Research An NMR pulse sequence for use in the borehole environment is provided which combines a modified fast inversion recovery (FIR) pulse sequence with a series of more than ten, and typically hundreds, of CPMG pulses according to See Patentfor Tabular Presentation PS where j is the index of the CPMG echoes gathered, i is the index of the wait times in the pulse sequence, Wi are the wait times, i are the recovery times
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New Patents
before the CPMG pulses, and tcp is the CarrPurcell spacing. Measurements are made of the signals induced in the formation as a result ofthe magnetic fields. Determinations of MO and/or Tl are then made from the measurements according to relationships which relate Mpo, Tl and T2 to the signal magnitude. Other relationships which provide stretched exponentials or multiple exponentials can also be used. From the MO and/or Tl determinations, formation parameters such as porosity and permeability may be derived according to equations known in the art. In obtaining the most accurate determinations of formation parameters in the least amount of time, the various pulse sequence parameters (I, J, Wi, and taui) are optimized prior to logging. Additional accuracy is obtained by integrating a gated portion of the echoes rather than by measuring amplitude, and by utilizing a phase alternated CPMG sequence in repetitive measurements in order to eliminate baseline shift error.
5023552 MAGNETIC RESONANCE DEVICE WITH A SELECTABLE GAIN SIGNAL AMPLIFIER Antoon F Mehlkopf, Boef Johannes H Den, Rolf J Lioen, Eindhoven, Netherlands assigned to U S Philips Corp A magnetic resonance imaging device and method are disclosed in which, during acquisition of measuring data the receiver gain is switched over in dependence of the signal strength, so that in principle every data set of the various measuring cycles has an optimum signal to noise ratio.
5023553 METHOD AND APPARATUS FOR BODY MOTION CORRECTIVE IMAGING Koich Sano, Tetsu Koizumi, Sagamihara, Hitachi Ltd
Yokoyama, Hideak Japan assigned to
In order to eliminate the degradation of NMR image caused by a body motion due to breathing or the like, one of measured image signals is selected as a reference, correlation is calculated between each measured image signal and the reference, and the image signal is modified on the basis of the value of correlation.
5023554 FRINGE FIELD MRI Zang-Hee Cho, Edward K Wong assigned to The Reagents of the University of California Extremely non-homogenous high but extremely intense high fringe magnetic fields are purposefully (and even advantageously) utilized for magnetic resonance imaging (including localization and spectroscopy) so as to better obtain advantages typically associated with ultra high field MRI. Static magnetic field gradients inherently included in such fringe fields are actively utilized in conjunction with suitable NMR RF nutation pulses so as to achieve volumeselective NMR data acquisition. Special arrangements of static electromagnets, magnetic gradient coils and/or RF coils may be used in conjunction with novel RF/gradient pulse sequences so as to elicit and acquire suitable MRI data.
5023555 MAGNETIC RESONANCE IMAGING Gosta J Ehnholm, Helsinki, Finland assigned to Instrumentarium Corporation The invention provides a magnetic resonance imaging apparatus having a primary field generating means for generating a substantially uniform magnetic field, wherein that said primary field generating means is arranged in use to generate a magnetic field the field direction of which varies with time, e.g. a rotating field. The varying field operates to average out from the magnetic field experienced by the sample being imaged at least some of the external perturbing magnetic fields so reducing the sensitivity of the apparatus to such external fields.
5023584 MAGNET CARTRIDGE FOR MAGNETIC RESONANCE MAGNET Evangelos Laskaris assigned to General Electric Company A cylindrical sleeve of thermally conductive material is provided together with two epoxy impregnated superconductive coils. The cylindrical
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angiogram using a single echo method. If the view angle of each echo is the same, then the acquired angiograms can be added to enhance the signal-to-noise ratio. Another pulse sequence simultaneously obtains two or more angiograms, each sensitive to one of two orthogonal flow components of the overall blood flow; the angiograms are then added to give an angiogram which is sensitive to total flow in all directions. Multiple velocity ranges are accommodated in a fourth sequence form.
5022405 STETHOSCOPE FOR USE IN NUCLEAR MAGNETIC RESONANCE DIAGNOSTICS J Bertil Hok, Valerie Bythell, Vs, Sweded assigned to Hok Instrument AB A stethoscope for use with nuclear magnetic resonance (NMR) screenings in order to supervise a patient, including a bell chest piece adapted to pick up audible heart and breathing sounds or other bodily sounds from the patient, a flexible hollow tube connected at one end thereof to the bell chest piece and adapted to transmit audible heart and breathing sounds from the bell chest piece. The novel features of the invention are, a microphone member adapted to be arranged at the opposite side the tube outside the zone of the maximum field strength of the NMR equipment and adapted to convert the acoustic signals into corresponding electrical signals, an optical transmitter to which the microphone member is connected and from which optical signals are transmitted to the surrounding in at least one direction, the optical signals corresponding to the electrical signals, and at least one receiver for receiving the optical signals from the optical transmitter and for converting the optical signals into electrical signals corresponding to said audible sounds.
5023072 PARAMAGNETIC SUPERPARAMAGNETIC FERROMAGNETIC SUCROSE SULFATE COMPOSITIONS FOR MAGNETIC RESONANCE IMAGING OF THE GASTROINTESTINAL TRACT Kenneth T Cheng assigned to University of New Mexico
The disclosure is directed to a sucrose sulfate composition useful for magnetic resonance imaging of the gastrointestinal tract. Paraferromagnetic magnetic/superparamagnetic ions or particles are attached to sucrose sulfate molecules in the composition. The sucrose sulfate composition travels, in the patient, to sites in the gastrointestinal tract which are diseased and ferthe paramagnetic/superparamagnetic romagnetic ions or particles allow magnetic resonance imaging to be more effective for imaging of these sites in the gastrointestinal tract.
5023185 METHOD FOR DETERMINING RESOLUTION POWER OR DISCRIMINATION CAPACITY OF AN NMR IMAGING APPARATUS Masao Nambu, Naoaki Yamada, Yokohama, Japan assigned to Nippon Oil Co Ltd A phantom for diagnosis by nuclear magnetic resonance imaging comprises a container made of a synthetic resin and a hydrogel sealingly contained in the container. The container has at least one opening into which a sample material is inserted. The hydrogel is prepared by charging an aqueous solution of a polyvinyl alcohol into the container, cooling the aqueous solution to minus 10 degreesc. or lower to obtain a cooled frozen mass and thawing the cooled frozen mass. Also disclosed is a method for determining resolution power or discrimination capacity of an NMR imaging apparatus.
5023551 NUCLEAR MAGNETIC RESONANCE PULSE SEQUENCES FOR USE WITH BOREHOLE LOGGING TOOLS Robert L Kleinberg, Abdurrahman Sezginer, Masafumi Fukuhara assigned to SchlumbergerDoll Research An NMR pulse sequence for use in the borehole environment is provided which combines a modified fast inversion recovery (FIR) pulse sequence with a series of more than ten, and typically hundreds, of CPMG pulses according to See Patentfor Tabular Presentation PS where j is the index of the CPMG echoes gathered, i is the index of the wait times in the pulse sequence, Wi are the wait times, i are the recovery times
III
New Patents
before the CPMG pulses, and tcp is the CarrPurcell spacing. Measurements are made of the signals induced in the formation as a result ofthe magnetic fields. Determinations of MO and/or Tl are then made from the measurements according to relationships which relate Mpo, Tl and T2 to the signal magnitude. Other relationships which provide stretched exponentials or multiple exponentials can also be used. From the MO and/or Tl determinations, formation parameters such as porosity and permeability may be derived according to equations known in the art. In obtaining the most accurate determinations of formation parameters in the least amount of time, the various pulse sequence parameters (I, J, Wi, and taui) are optimized prior to logging. Additional accuracy is obtained by integrating a gated portion of the echoes rather than by measuring amplitude, and by utilizing a phase alternated CPMG sequence in repetitive measurements in order to eliminate baseline shift error.
5023552 MAGNETIC RESONANCE DEVICE WITH A SELECTABLE GAIN SIGNAL AMPLIFIER Antoon F Mehlkopf, Boef Johannes H Den, Rolf J Lioen, Eindhoven, Netherlands assigned to U S Philips Corp A magnetic resonance imaging device and method are disclosed in which, during acquisition of measuring data the receiver gain is switched over in dependence of the signal strength, so that in principle every data set of the various measuring cycles has an optimum signal to noise ratio.
5023553 METHOD AND APPARATUS FOR BODY MOTION CORRECTIVE IMAGING Koich Sano, Tetsu Koizumi, Sagamihara, Hitachi Ltd
Yokoyama, Hideak Japan assigned to
In order to eliminate the degradation of NMR image caused by a body motion due to breathing or the like, one of measured image signals is selected as a reference, correlation is calculated between each measured image signal and the reference, and the image signal is modified on the basis of the value of correlation.
5023554 FRINGE FIELD MRI Zang-Hee Cho, Edward K Wong assigned to The Reagents of the University of California Extremely non-homogenous high but extremely intense high fringe magnetic fields are purposefully (and even advantageously) utilized for magnetic resonance imaging (including localization and spectroscopy) so as to better obtain advantages typically associated with ultra high field MRI. Static magnetic field gradients inherently included in such fringe fields are actively utilized in conjunction with suitable NMR RF nutation pulses so as to achieve volumeselective NMR data acquisition. Special arrangements of static electromagnets, magnetic gradient coils and/or RF coils may be used in conjunction with novel RF/gradient pulse sequences so as to elicit and acquire suitable MRI data.
5023555 MAGNETIC RESONANCE IMAGING Gosta J Ehnholm, Helsinki, Finland assigned to Instrumentarium Corporation The invention provides a magnetic resonance imaging apparatus having a primary field generating means for generating a substantially uniform magnetic field, wherein that said primary field generating means is arranged in use to generate a magnetic field the field direction of which varies with time, e.g. a rotating field. The varying field operates to average out from the magnetic field experienced by the sample being imaged at least some of the external perturbing magnetic fields so reducing the sensitivity of the apparatus to such external fields.
5023584 MAGNET CARTRIDGE FOR MAGNETIC RESONANCE MAGNET Evangelos Laskaris assigned to General Electric Company A cylindrical sleeve of thermally conductive material is provided together with two epoxy impregnated superconductive coils. The cylindrical