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4818940 Method for measuring nuclear magnetic resonance
New Patents
at major intersections which are converted into a slice image. Rapid line scan imaging is achieved by successive diagonal excitation of previously unexcited regions. Spoiler magnetic gradient fields and applied periodically to dephase and in turn eliminate minor or spurious echoes from other intersections of the two normal diagonal planes.
v
and different gradient fields, is executed twice, the gradient fields being influenced so that the distance between Ihe high-frequency pulse and the echo signal in one execution of a sequence deviates from that in the other execution of the sequence by a given amount. Water images and fat images can thus be formed by summing and subtraction, respectively. In a second embodiment, two read phases are provided in each sequence.
4818940 METHOD FOR MEASURING NUCLEAR MAGNETIC RESONANCE Jurgen Hennig, Arno Nauerth, Freiburg, Federal Republic Of Germany assigned to Bruker Medizintechnik GmbH For recording a nuclear magnetic resonance tomogram according to a Fourier-transform method, a Carr-Purcell-Gill-Meiboom pulse sequence is used for the excitation of a body to produce a sequence of spin-echo signals. A timelimited phase-encoding magnetic gradient field GX is imposed between each pair of 180 degrees pulses of the sequence. The phase-encoding magnetic gradient field is modified after every I80 degrees pulse so that every spin-echo signal corresponds to a different projection of the body. The magnetic gradient fields used in the recording are regulated in intensity and duration in such a way that a spin-phase condition at each I80 degrees pulse of the pulse sequence remains effectively constant. Thereby, it is possible to construct a complete tomographic recording with a single pulse-sequence excitation, so that the time required for such recordings can be reduced to a fraction of the time needed for nuclear-magnetic-resonance recording tomograms conventionally.
4818941 MR TOMOGRAPHY METHOD AND APPARATUS FOR PERFORMING THE METHOD Graeme C McKinnon, Ellerau, Federal Republic Qf Germany assigned to U S Philips Corporation An MR tomography method for generating water and fat images and an apparatus for performing the method. In one embodiment each sequence, consisting of a high-frequency pulse
4819254 METHOD OF AND APPARATUS FOR REZORDING A REPRODUCING IMAGE INFORMATION IN PAN X-RAY PHOTOGRA Timo Nieminen, Tero Nieminen, Helsinki, Finland assigned to Fkadiante Oy The invention relates to a method of and an apparatus for recording image information in panoramic X-ray photography. The total information contained in a beam of X-rays penetrated through an object is recorded on a memory disc, whose configuration is substantially the same as that of an object to be imaged, such as a dental arch, said memory disc being kept stationary during the filming relative to the object to be imaged. The memory disc is used for producing or presenting layerwise reproduced images of desired layers. The preparation of reproduced images from the memory disc can be performed on a principle corresponding to conventional panoramic tomography with the exception that the object to be imaged is a memory disc.
4820983 METHOD AND APP PERFORMING EXPERIMENT Max R Bendall: David Queensland, Australia
T Pegg, Burbank,
In a method for NMR excitation of a sample, an Rf pulse is applied to an irradiation coil (6) proximate the sample, in the presence of an external DC magnetic field and an adiabatic passage is performed wherein the Rf pulse is controlled such that: See Patentfor Tabular Presentation PS See Patent for Tabular Presentatiola PS ,YeePatent for Tabular Presentation
PS where s = §/A,
at major intersections which are converted into a slice image. Rapid line scan imaging is achieved by successive diagonal excitation of previously unexcited regions. Spoiler magnetic gradient fields and applied periodically to dephase and in turn eliminate minor or spurious echoes from other intersections of the two normal diagonal planes.
v
and different gradient fields, is executed twice, the gradient fields being influenced so that the distance between Ihe high-frequency pulse and the echo signal in one execution of a sequence deviates from that in the other execution of the sequence by a given amount. Water images and fat images can thus be formed by summing and subtraction, respectively. In a second embodiment, two read phases are provided in each sequence.
4818940 METHOD FOR MEASURING NUCLEAR MAGNETIC RESONANCE Jurgen Hennig, Arno Nauerth, Freiburg, Federal Republic Of Germany assigned to Bruker Medizintechnik GmbH For recording a nuclear magnetic resonance tomogram according to a Fourier-transform method, a Carr-Purcell-Gill-Meiboom pulse sequence is used for the excitation of a body to produce a sequence of spin-echo signals. A timelimited phase-encoding magnetic gradient field GX is imposed between each pair of 180 degrees pulses of the sequence. The phase-encoding magnetic gradient field is modified after every I80 degrees pulse so that every spin-echo signal corresponds to a different projection of the body. The magnetic gradient fields used in the recording are regulated in intensity and duration in such a way that a spin-phase condition at each I80 degrees pulse of the pulse sequence remains effectively constant. Thereby, it is possible to construct a complete tomographic recording with a single pulse-sequence excitation, so that the time required for such recordings can be reduced to a fraction of the time needed for nuclear-magnetic-resonance recording tomograms conventionally.
4818941 MR TOMOGRAPHY METHOD AND APPARATUS FOR PERFORMING THE METHOD Graeme C McKinnon, Ellerau, Federal Republic Qf Germany assigned to U S Philips Corporation An MR tomography method for generating water and fat images and an apparatus for performing the method. In one embodiment each sequence, consisting of a high-frequency pulse
4819254 METHOD OF AND APPARATUS FOR REZORDING A REPRODUCING IMAGE INFORMATION IN PAN X-RAY PHOTOGRA Timo Nieminen, Tero Nieminen, Helsinki, Finland assigned to Fkadiante Oy The invention relates to a method of and an apparatus for recording image information in panoramic X-ray photography. The total information contained in a beam of X-rays penetrated through an object is recorded on a memory disc, whose configuration is substantially the same as that of an object to be imaged, such as a dental arch, said memory disc being kept stationary during the filming relative to the object to be imaged. The memory disc is used for producing or presenting layerwise reproduced images of desired layers. The preparation of reproduced images from the memory disc can be performed on a principle corresponding to conventional panoramic tomography with the exception that the object to be imaged is a memory disc.
4820983 METHOD AND APP PERFORMING EXPERIMENT Max R Bendall: David Queensland, Australia
T Pegg, Burbank,
In a method for NMR excitation of a sample, an Rf pulse is applied to an irradiation coil (6) proximate the sample, in the presence of an external DC magnetic field and an adiabatic passage is performed wherein the Rf pulse is controlled such that: See Patentfor Tabular Presentation PS See Patent for Tabular Presentatiola PS ,YeePatent for Tabular Presentation
PS where s = §/A,