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4972836 Motion detector for high-resolution magnetic resonance imaging
New Patents
IV
4970465 MAGNETIC RESONANCE IMAGING SYSTEM AND METHOD Masayuki Hagiwara, Ootawara, to Kabushiki Kaisha Toshiba
Japan
assigned
A magnetic resonance imaging system comprises a static field generating section, a gradient field applying section, a high-frequency pulse applying section, a sequence control section, a receiving section, and an imaging processing section. The sequence control section includes a first echo excitation section for sequentially applying a 90 degrees pulse and a 180 degrees pulse to the object, thereby generating a first magnetic resonance echo signal, a second echo excitation section for applying a 180 degrees pulse once again after the first magnetic resonance echo signal is generated, thereby generating a second magnetic resonance echo signal, and a compensating section for applying a gradient magnetic field to the object in accordance with a predetermined sequence pattern, between the first magnetic resonance echo signal and the second magnetic resonance echo signal, thereby causing the phase of a magnetic resonance echo signal corresponding to a specific moving atomic nucleus to match with the phase of a magnetic resonance echo signal corresponding to a specific static atomic nucleus at a time instance corresponding to a peak of the second echo signal.
4972147 MAGNETIC RESONANCE METHOD FOR OBTAINING SELECTEDSPECTRA Johannes J Van Vaals, Eindhoven, Netherlands assigned to U S Philips Corporation The method includes a critical time shift of a refocusing pulse between two (90 degrees) excitation pulses which produce multiple quantum coherence signals and which are followed by a (90 degrees) read pulse (using a critical timing a refocusing pulse serving the same purpose can also be applied between the second excitation pulse and the read pulse). With respect to the center of the time path between the excitation
pulses or between the excitation pulse and the read pulse the time shift is chosen to be such that give resonances do not occur positively or negatively in the spectrum whereas other resonances do occur therein (i.e. at substantially maximum strength). The MRI method can be combined with the use of spatially selective gradients in order to obtain localized spectra or images.
4972148 MAGNETIC RESONANCE TOMOGRAPHY METHOD AND MAGNETIC RESONANCE TOMOGRAPHY APPARATUS FOR PERFORMING THE METHOD Jens D Jensen, Hamburg, Federal Republic Of Germany assigned to U S Philips Corporation The invention relates to a magnetic resonance tomography method where two slice-selective rf pulses influence the nuclear magnetization in a slice. Further slice selective rf pulses which excite sub-slices extending perpendicularly to said slice generate stimulated echo signals in the stripshaped zone of intersection between the relevant sub-slice and the slice. The FID signals associated with the further rf pulses are suppressed by means of a subsequently activated magnetic gradient field. In order to ensure that this field does not dephase the desired stimulated echo signals at the same time magnetic gradient field having the same time integral is activated between the first and the second rf pulse.
4972836 MOTION DETECTOR FOR HIGH-RESOLUTION MAGNETIC RESONANCE IMAGING John Schenck, Steven Souza, David signed to General Electric Company
Eisner
as-
Apparatus for detecting movement of an anatomical sample undergoing NMR imaging uses at least one optical sensor, each having an output responsive to the intensity of received illumination and each directed to view a selected portion of sample; and apparatus for monitoring the output of each sensor to detect a change therein responsive to movement of the sample.
IV
4970465 MAGNETIC RESONANCE IMAGING SYSTEM AND METHOD Masayuki Hagiwara, Ootawara, to Kabushiki Kaisha Toshiba
Japan
assigned
A magnetic resonance imaging system comprises a static field generating section, a gradient field applying section, a high-frequency pulse applying section, a sequence control section, a receiving section, and an imaging processing section. The sequence control section includes a first echo excitation section for sequentially applying a 90 degrees pulse and a 180 degrees pulse to the object, thereby generating a first magnetic resonance echo signal, a second echo excitation section for applying a 180 degrees pulse once again after the first magnetic resonance echo signal is generated, thereby generating a second magnetic resonance echo signal, and a compensating section for applying a gradient magnetic field to the object in accordance with a predetermined sequence pattern, between the first magnetic resonance echo signal and the second magnetic resonance echo signal, thereby causing the phase of a magnetic resonance echo signal corresponding to a specific moving atomic nucleus to match with the phase of a magnetic resonance echo signal corresponding to a specific static atomic nucleus at a time instance corresponding to a peak of the second echo signal.
4972147 MAGNETIC RESONANCE METHOD FOR OBTAINING SELECTEDSPECTRA Johannes J Van Vaals, Eindhoven, Netherlands assigned to U S Philips Corporation The method includes a critical time shift of a refocusing pulse between two (90 degrees) excitation pulses which produce multiple quantum coherence signals and which are followed by a (90 degrees) read pulse (using a critical timing a refocusing pulse serving the same purpose can also be applied between the second excitation pulse and the read pulse). With respect to the center of the time path between the excitation
pulses or between the excitation pulse and the read pulse the time shift is chosen to be such that give resonances do not occur positively or negatively in the spectrum whereas other resonances do occur therein (i.e. at substantially maximum strength). The MRI method can be combined with the use of spatially selective gradients in order to obtain localized spectra or images.
4972148 MAGNETIC RESONANCE TOMOGRAPHY METHOD AND MAGNETIC RESONANCE TOMOGRAPHY APPARATUS FOR PERFORMING THE METHOD Jens D Jensen, Hamburg, Federal Republic Of Germany assigned to U S Philips Corporation The invention relates to a magnetic resonance tomography method where two slice-selective rf pulses influence the nuclear magnetization in a slice. Further slice selective rf pulses which excite sub-slices extending perpendicularly to said slice generate stimulated echo signals in the stripshaped zone of intersection between the relevant sub-slice and the slice. The FID signals associated with the further rf pulses are suppressed by means of a subsequently activated magnetic gradient field. In order to ensure that this field does not dephase the desired stimulated echo signals at the same time magnetic gradient field having the same time integral is activated between the first and the second rf pulse.
4972836 MOTION DETECTOR FOR HIGH-RESOLUTION MAGNETIC RESONANCE IMAGING John Schenck, Steven Souza, David signed to General Electric Company
Eisner
as-
Apparatus for detecting movement of an anatomical sample undergoing NMR imaging uses at least one optical sensor, each having an output responsive to the intensity of received illumination and each directed to view a selected portion of sample; and apparatus for monitoring the output of each sensor to detect a change therein responsive to movement of the sample.