2355 results about "X-ray tube" patented technology

An X-ray computed tomography apparatus includes a first X-ray tube configured to generate X-rays with which a subject to be examined is irradiated, a first X-ray detector configured to detect X-rays transmitted through the subject, a second X-ray tube which generates X-rays with which a treatment target of the subject is irradiated, a rotating mechanism which rotates the first X-ray tube, the first X-ray detector, and the second X-ray tube around the subject, a reconstructing unit configured to reconstruct an image on the basis of data detected by the first X-ray detector, and a support mechanism which supports the second X-ray tube. The central axis of X-rays from the second X-ray tube tilts with respect to a body axis of the subject. This makes it possible to reduce the dose on a portion other than a treatment target.

Embodiments of the invention relate to omni-tomographic imaging or grand fusion imaging, i.e., large scale fusion of simultaneous data acquisition from multiple imaging modalities such as CT, MRI, PET, SPECT, US, and optical imaging. A preferred omni-tomography system of the invention comprises two or more imaging modalities operably configured for concurrent signal acquisition for performing ROI-targeted reconstruction and contained in a single gantry with a first inner ring as a permanent magnet; a second middle ring containing an x-ray tube, detector array, and a pair of SPECT detectors; and a third outer ring for containing PET crystals and electronics. Omni-tomography offers great synergy in vivo for diagnosis, intervention, and drug development, and can be made versatile and cost-effective, and as such is expected to become an unprecedented imaging platform for development of systems biology and modern medicine.

A high speed computed tomography x-ray scanner using a plurality of x-ray generators. Each x-ray generator is scanned along a source path that is a segment of the scanner's source path such that each point in the source path is scanned by at least one tube. X-ray generators and detectors can be arranged in different scan planes depending on the available hardware so that a complete and near planar scan of a moving object can be assembled and reconstructed into an image of the object.

A dual energy scanning densitometry system for imaging and measuring bone density maintains acceptable flux by adjusting the x-ray current or scan speed according to preceding scan line data. The amount of acceptable flux is maintained within limits modified by information about the region of the body being scanned so that different precisions may be maintained for different body regions. Scan speed and current may be controlled so that scan speed is maximized within the current limits. Essentially continuous flux control can be achieved.

A method of and system for performing intravenous tomographic digital angiography imaging which combines the principles of intravenous digital angiography with those of cone-beam volume tomography for generating a direct, unambiguous and accurate 3-D reconstruction of stenosis and other irregularities and malformations from 2-D cone-beam tomography projections is disclosed in which several different data acquisition geometries, such as a circle-plus-arc data acquisition geometry, may be utilized to provide a complete set of data so that an exact 3-D reconstruction is obtained. Only a single IV contrast injection with a short breathhold by the patient is needed for use with a volume CT scanner which uses a cone-beam x-ray source and a 2-D detector for fast volume scanning in order to provide true 3-D descriptions of vascular anatomy with more than 0.5 lp/mm isotropic resolution in the x, y and z directions is utilized in which one set of cone-beam projections is acquired while rotating the x-ray tube and detector on the CT gantry and then another set of projections is acquired while tilting the gantry by a small angle. The projection data is preweighted and the partial derivatives of the preweighted projection data are calculated. Those calculated partial derivatives are rebinned to the first derivative of the Radon transform, for both the circular orbit data and the arc orbit data. The second partial derivative of the Radon transform is then calculated and then the reconstructed 3-D images are obtained by backprojecting using the inverse Radon transform.

An x-ray generating device includes a field emission cathode formed at least partially from a nanostructure-containing material having an emitted electron current density of at least 4 A/cm². High energy conversion efficiency and compact design are achieved due to easy focusing of cold cathode emitted electrons and dramatic reduction of heating at the anode. In addition, by pulsing the field between the cathode and the gate or anode and focusing the electron beams at different anode materials, pulsed x-ray radiation with varying energy can be generated from a single device. Methods and apparatus for independent control of electron emission current and x-ray energy in x-ray tubes are also provided. The independent control can be accomplished by adjusting the distance between the cathode and anode. The independent control can also be accomplished by adjusting the temperature of the cathode. The independent control can also be accomplished by optical excitation of the cathode. The cathode can include field emissive materials such as carbon nanotubes.

A baggage scanning system and method employ combined angular and energy dispersive x-ray scanning to detect the presence of a contraband substance within an interrogation volume of a baggage item. The interrogation volume is illuminated with penetrating, polychromatic x-rays in a primary fan beam from a source such as a tungsten-anode x-ray tube. An energy-dependent absorption correction is determined from measurement of the attenuation of the fan beam at a plurality of different energies. Radiation coherently scattered by substances in the interrogation volume is detected by an energy-resolved x-ray detector operated at a plurality of scattering angles to form a plurality of scattering spectra. Each scattering spectrum is corrected for energy-dependent absorption and the corrected spectra are combined to produce a scattering pattern. The experimental scattering pattern is compared with reference patterns that uniquely characterize known contraband substances. The system and method can locate and identify a wide variety of contraband substances in an accurate, reliable manner. The system provides for automated screening, with the result that vagaries of human performance are virtually eliminated. False alarms and the need for hand inspection are reduced and detection efficacy is increased.

An X-ray diagnostic apparatus includes a floor rotating arm which is installed at one end on a floor surface so as to be rotatable around a first rotation axis, a C-arm which is mounted on the other end of the floor rotating arm so as to be rotatable around a second rotation axis, an X-ray tube which is mounted on one end of the C-arm, an X-ray detector which is mounted on the other end of the C-arm, and a bed which has a table top provided to be movable along a longitudinal axis. The bed is placed such that the longitudinal axis is spaced apart from the first rotation axis by a predetermined distance.

An x-ray system is disclosed that includes a bipolar x-ray tube. The bipolar x-ray tube includes two insulators that are separated by an intermediate electrode in an embodiment, wherein each insulator forms a portion of an outer wall of a vacuum envelope of the bipolar x-ray tube surrounding at least a portion of a path of an electron beam within the vacuum envelope. In further embodiments, the bipolar x-ray tube includes a first electrode at a positive high voltage potential with respect to a reference potential, a second electrode at a negative high voltage potential with respect to the reference potential, and an x-ray transmissive window that is at the positive high voltage potential.

Described is a self-contained, small, lightweight, power-efficient and radiation-shielded module that includes a miniature vacuum X-ray tube emitting X-rays of a controlled intensity and defined spectrum. Feedback control circuits are used to monitor and maintain the beam current and voltage. The X-ray tube, high-voltage power supply, and the resonant converter are encapsulated in a solid high-voltage insulating material. The module can be configured into complex geometries and can be powered by commercially available small, compact, low-voltage batteries.

An x-ray tube comprising an electron gun assembly having an electron gun container housing an electron generator for generating electrons in a first direction along a first axis. The beam of electrons impinges upon an anode which emits x-rays in response to the beam of electrons. The gun container is characterized by having a discharge end comprising a solid spherical shape.

A dual filament x-ray tube assembly (16) includes an evacuated envelope (52) having an anode (54) disposed at a first end of the evacuated envelope (52) and a cathode assembly (62) disposed at a second end of the evacuated envelope (52). The cathode assembly includes a variable-length filament assembly (72, 74; 100) which emits electron beams for impingement on the anode (54) at focal spots having varying lengths. The cathode assembly (62) further includes a cathode cup (64, 66, 68; 110, 112) which is subdivided into a plurality of electrically insulated deflection electrodes (64, 66, 68; 110, 112). A filament select circuit (80) selectively and individually heats a portion of the variable-length filament assembly (72, 74). Electron beams emitted from the filament assembly (72, 74) are electrostatically focused and controlled by applying potentials to different ones of the deflection electrodes (64, 66, 68; 110, 112). The x-ray tube assembly (16) provides longer focal spots for thick-slice scanning applications and shorter focal spots for thin-slice scanning applications along with the benefit of electrostatic focusing and control.

An X-ray tomographic imaging apparatus includes an X-ray and a direct conversion type of detector. The X-ray tube and the detector are supported by the support means so as to be rotatable along curved orbits mutually independently. Under instructions from a computer, scans and image reconstruction are performed. The X-ray tube and the detector are moved along the orbits mutually independently so that X-ray beams are always transmitted through a desired tomographic plane of an object at desired angles. Acquired frame data are used to produce a panoramic image of the plane, while the frame data and the panoramic image are used to produce a tomographic image in which structural components of the object are optically focused and distortions caused due to differences in X-ray paths are suppressed. The apparatus can be used as devices for dental, medical diagnosis and nondestructive inspection, and can have a CT imaging function.

Described is a self-contained, small, lightweight, power-efficient and radiation-shielded module that includes a miniature vacuum X-ray tube emitting X-rays of a controlled intensity and defined spectrum. Feedback control circuits are used to monitor and maintain the beam current and voltage. The X-ray tube, high-voltage power supply, and the resonant converter are encapsulated in a solid high-voltage insulating material. The module can be configured into complex geometries and can be powered by commercially available small, compact, low-voltage batteries.