General Electric Company

Rowland W Redington

William A Edelstein

Lowell Scott Smith

Paul Arthur Bottomley

John L Henkes

William Macomber Leue

John F Schenck

Howard Roscoe Hart, Jr

Steven G Karr

Leon Axel

David R Eisner

Raymond J Hodsoll, Jr

Walter H Berninger

A magnetic resonance system for both imaging and spectroscopy of a sample of non-magnetic material (such as a portion of the human anatomy and the like) at one static magnetic field magnitude in excess of 0.7 Tesla (T), utilizes a superconducting magnet having a room-temperature bore of diameter sufficiently large to place therein not only the desired sample but also a set of gradient magnetic field-producing coils and at least one radio-frequency coil for exciting and/or receiving response signals from the sample to be examined. The entire magnetic system has suitably-small temporal and positional field variations to allow imaging to be accomplished at the resonant frequencies of nuclei including .sup.1 H, .sup.13 C, .sup.19 F, .sup.23 Na and .sup.31 P. The system includes a novel interface subsystem, itself including a novel gradient signal switching circuit, for acquiring imaging data in relatively short time intervals.

High-field nuclear magnetic resonance imaging/spectroscopy system

Power line interference artifacts in a magnetic resonance image are minimized by the process of: providing a sequential plurality of imaging signal sequences, the totality of which sequences is required for determining the value of each image pixel in an image array thereof; requesting the start of each sequence of the plurality of imaging signal sequences prior to the actual time at which each such signal sequence should commence; preparing a recognition element prior to the desired actual commencement time; recognizing a predetermined occurrence of a repetitive power line signal parameter to provide a first signal; setting the recognition element responsive to the first signal to only then cause the signal sequence start request to actually cause commencement of the associated signal sequence; and causing each signal sequence to occur in essentially an integral number of sequential repetitive cycles of the power line signal waveform to minimize the magnitude of power line frequency signal interference artifacts in the resulting magnetic resonance image.

Method of, and apparatus for, minimizing magnetic resonance imaging

An improved method for providing a high-spatial-resolution NMR image, having resolved artifact-free NMR images of chemically-shifted nuclei, includes: forming a pair of NMR images each having imaging components of each of the chemically-shifted nuclei due to projections in one of a pair of opposite directions along a common line; mirroring the imaging components of one of the NMR images about a line orthogonal to the common line; registering and combining the mirrored image and the other image to eliminate a first one of the components and thus produce a composite image containing only the other component and a negative of the other component offset by twice the chemical shift; and forming a resolved image of the other component by processing the composite image to eliminate the offset negative image. The resolved image may then be combined with one or more of the NMR images to produce a resolved image of the first component. The method requires only 2N projections to form the two N-by-N NMR images.

Method for high-spatial-resolution spectroscopic NMR imaging of

A radio-frequency shielded room for a nuclear magnetic resonance imaging system has at least one electrically-conductive shield wall substantially enclosing a predetermined volume adjacent to one end of the bore formed through an imaging magnet within which bore the imaging process is carried out. The at least one wall has an aperture therethrough substantially at and in registration with the one bore end. A hollow shield member, of an electrically-conductive material, extends through the magnet bore and has a first end region periphery aligned with and substantially electrically connected to the entire periphery of the aperture in the at least one wall. A second end of hollow shield member extends at least to the remaining end of the magnet bore, where it is enclosed with an electrically-conductive cap substantially electrically connected about the entire periphery of the hollow shield member second end. The at least one wall, the hollow shield member and the second end cap form a shielded room substantially completely enclosing the volume extending through the magnet bore and adjacent to one end thereof, which volume is effectively shielded from radio frequency signals emanating from outside the enclosed volume.

RF shielded room for NMR imaging system

A method for providing a high-spatial-resolution NMR image, having resolved artifact-free NMR images of chemically-shifted nuclei, includes: forming independent NMR images having imaging components due to each of the chemically-shifted nuclei; registering and combining the images to eliminate one of the components and produce a composite image containing the other component and a negative of the other component offset by the chemical shift; and forming a resolved image of the component by processing the composite image to eliminate the negative. The resolved image may then be combined with one or more of the NMR images to produce a resolved image of the first component. The method requires only 2N projections to form the two independent N-by-N NMR images.

High-spatial-resolution spectroscopic NMR imaging of chemically-shifted

A method and apparatus for producing two-dimensional, plan view images of in vivo blood flow networks using unique nuclear magnetic resonance (NMR) pulse sequences are disclosed. The method teaches the use of a pair of 90.degree. selective pulses separated by a delay time optimized to provide images with enhanced blood flow contrast by discriminating against stationary media surrounding the blood flow path. For the instant method, two-dimensional images are compiled by the illustrative apparatus using a collection of NMR slice data, wherein each slice reflects a one-dimensional projection of NMR received signal data in a thin planar slab selected to be generally orthogonal to the primary blood flow network. Further alternative embodiments discuss the use of free induction decay (FID) signals, as well as single pulse and multiple pulse spin echo sequences.

NMR blood flow imaging

A cathode ray tube of the shadow mask type has a layer of high atomic number material fabricated upon the shadow mask surface nearest to at least one electron gun, to increase backscatter of electrons impinging upon the non-aperture areas of the shadow mask, thereby reducing local heating of the mask and maintaining color purity of the cathode ray tube even at increased brightness levels.

Shadow mask having a layer of high atomic number material on gun side

A multiple source, rotating, tomographic x-ray scanner includes x-ray sources adaptably configurable to operate in two modes. The first mode of operation, in which the sources are planarly configured, permits high speed, single slice scans to be made. The second mode of operation in which the x-ray sources are configured so as to scan distinct, but contiguous planes, permits multiple slices to be made in a single scan.

Multiple purpose high speed tomographic x-ray scanner

A mammography machine for examination of a pendant breast contained in a fluid transmission medium. Patient support is provided at the upper rib cage, lower rib cage, and the shoulder adjacent the breast undergoing examination. X-ray scans are accomplished by rotation about a vertical axis extending through the pendant breast. Patient loading is facilitated by a fabric sling rotatably affixed about a horizontal axis adjacent the lower body of the patient.

Mammography table

1. The method of manufacturing a camera tube target from a semiconductor material for placement in a camera tube prior to degassing thereof comprising the steps of initially doping the semiconductor material with an impurity for rendering it sensitive to a desired radiation spectrum but in a quantity less than required for sensitivity in said desired radiation spectrum; annealing said semiconductor material at a temperature greater than the subsequent degassing temperature for a period of time effective to increase the impurity concentration to a level sufficient to render the semicoductor material sensitive to the desired radiation spectrum, said concentration being substantially more stable at lower degassing temperatures than the initial impurity concentration; positioning said semiconductor material as a target within a radiation sensitive camera tube enclosure; and degassing said camera tube enclosure by heating said enclosure including said target for driving the gas from said enclosure.

Method of manufacturing semiconductor camera tube targets

A mammography machine for examination of a pendant breast contained in a fluid transmission medium. Patient suppport is provided at the upper rib cage, lower rib cage, and the shoulder adjacent the breast undergoing examination. X-rays scans are accomplished by rotation about a vertical axis extending through the pendant breast. Patient loading is facilitated by a fabric sling rotatably affixed about a horizontal axis adjacent the lower body of the patient.

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Schenectady, NY, United States of America

Rowland W Redington