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4961426 Method for retrospectively gating NMR data
II
New Patents
A system for automatically determining the outline of a selected anatomical feature or region (e.g., in a slice of magnetic resonance data) and then making a quantitative determination of a morphometric parameter (such as area or volume) associated with the feature. A volumetric measurement of the feature is made by determining for each slice the areas within the outline for the feature and summing the areas for all the slices; the outlines are based on intensity contours, where the intensity of the contour is intermediate that within and outside of the feature; the intermediate intensity is chosen objectively based on a histogram of intensity levels; interpolation is used to assign contour locations in areas where the intensity of the contour is not present exactly; the accuracy of the outline is improved using an edge-optimization procedure in which the outline is shifted transversely to the location at which an estimate of the derivative (e.g., the Sobel operator) is a maximum; an alternative technique for choosing the initial outline is to examine the drop or rise in intensity afong a radical direction from a starting point within the region of interest and assign the contour to the location at which the difference in intensity reaches a predetermined value; the optimized outline for the first slice of data is saved and used as the initial outline for the adjoining slice, and the procedure of adjusting the outline transversely to the location at which a derivative estimate is a maximum is repeated, and so on, until outlines have been generated for all slices.
4962357 TWO-DIMENSIONAL METHOD FOR SPECTRAL EDITING OF NMR SIGNALS PRODUCED BY METABOLITES CONTAINING COUPLED SPINS Christopher
H Sotak
An NMR method for acquiring the volume localized, in vivo proton spectra of spin-spin coupled metabolites employs a series of stimulated echo pulse sequences (90-TE/2-90-t l90-TE/Z). The value of period tl is different for each of the pulse sequences in the series, and the NMR signals produced by the series of pulse sequences are acquired and digitized to form a two-dimensional data array. A two-dimensional Fourier transformation is performed on this data array to produce an array of data that is employed to generate a contour plot.
4962763 MAGNETIC RESONANCE IMAGE SYNTHESIZING SYSTEM Shinichi Sato, Koichi Sano, Hideki Koizumi, Yokohama, Hitachi Ltd
4961426 METHOD FOR RETROSPECTIVELY GATING NMR DATA Thomas Siemens
Spraggins, Steven Owens Medical Systems Inc
assigned
to
NMR imaging data are acquired using a variable phase-encoding gradient. NMR nonimaging data are acquired using fixed phaseencoding, and motion data are derived from such NMR non-imaging data. Gating data are extracted from the motion data and used to select from the NMR imaging data to produce gated image data. The gated image data are used to produce a reconstructed image.
Tetsu Yokoyama, Japan assigned to
A magnetic resonance image synthesizing system comprising a magnetic field generating section for generating a static magnetic field, a gradient magnetic field and a radio-frequency magnetic field and for irradiating those magnetic fields to an object to be examined, a receiver for detecting a magnetic resonance signal supplied from the object to be examined, a processing unit for calculating and constructing an MR image and distribution of blood velocity or relaxation time on the basis of the detected nuclear magnetic resonance signal, a sequence control section for controlling the gradient magnetic field and the radio-frequency magnetic field as well as the receiver, a display unit for displaying an MR image, and a manipulation section for specifying a necessary position on the screen of the display unit, the processing unit further making the display unit display an MR image calculated and synthesized on the basis of scanning parameters and a blood velocity or relaxation time defined in accordance with a position specified in the manipulation section.
New Patents
A system for automatically determining the outline of a selected anatomical feature or region (e.g., in a slice of magnetic resonance data) and then making a quantitative determination of a morphometric parameter (such as area or volume) associated with the feature. A volumetric measurement of the feature is made by determining for each slice the areas within the outline for the feature and summing the areas for all the slices; the outlines are based on intensity contours, where the intensity of the contour is intermediate that within and outside of the feature; the intermediate intensity is chosen objectively based on a histogram of intensity levels; interpolation is used to assign contour locations in areas where the intensity of the contour is not present exactly; the accuracy of the outline is improved using an edge-optimization procedure in which the outline is shifted transversely to the location at which an estimate of the derivative (e.g., the Sobel operator) is a maximum; an alternative technique for choosing the initial outline is to examine the drop or rise in intensity afong a radical direction from a starting point within the region of interest and assign the contour to the location at which the difference in intensity reaches a predetermined value; the optimized outline for the first slice of data is saved and used as the initial outline for the adjoining slice, and the procedure of adjusting the outline transversely to the location at which a derivative estimate is a maximum is repeated, and so on, until outlines have been generated for all slices.
4962357 TWO-DIMENSIONAL METHOD FOR SPECTRAL EDITING OF NMR SIGNALS PRODUCED BY METABOLITES CONTAINING COUPLED SPINS Christopher
H Sotak
An NMR method for acquiring the volume localized, in vivo proton spectra of spin-spin coupled metabolites employs a series of stimulated echo pulse sequences (90-TE/2-90-t l90-TE/Z). The value of period tl is different for each of the pulse sequences in the series, and the NMR signals produced by the series of pulse sequences are acquired and digitized to form a two-dimensional data array. A two-dimensional Fourier transformation is performed on this data array to produce an array of data that is employed to generate a contour plot.
4962763 MAGNETIC RESONANCE IMAGE SYNTHESIZING SYSTEM Shinichi Sato, Koichi Sano, Hideki Koizumi, Yokohama, Hitachi Ltd
4961426 METHOD FOR RETROSPECTIVELY GATING NMR DATA Thomas Siemens
Spraggins, Steven Owens Medical Systems Inc
assigned
to
NMR imaging data are acquired using a variable phase-encoding gradient. NMR nonimaging data are acquired using fixed phaseencoding, and motion data are derived from such NMR non-imaging data. Gating data are extracted from the motion data and used to select from the NMR imaging data to produce gated image data. The gated image data are used to produce a reconstructed image.
Tetsu Yokoyama, Japan assigned to
A magnetic resonance image synthesizing system comprising a magnetic field generating section for generating a static magnetic field, a gradient magnetic field and a radio-frequency magnetic field and for irradiating those magnetic fields to an object to be examined, a receiver for detecting a magnetic resonance signal supplied from the object to be examined, a processing unit for calculating and constructing an MR image and distribution of blood velocity or relaxation time on the basis of the detected nuclear magnetic resonance signal, a sequence control section for controlling the gradient magnetic field and the radio-frequency magnetic field as well as the receiver, a display unit for displaying an MR image, and a manipulation section for specifying a necessary position on the screen of the display unit, the processing unit further making the display unit display an MR image calculated and synthesized on the basis of scanning parameters and a blood velocity or relaxation time defined in accordance with a position specified in the manipulation section.