Abstract:
In an X-ray detector and method for applying a stray radiation grid onto an X-ray detector having detector elements arranged in a matrix that form a detector surface having detection regions sensitive to X-rays and less sensitive intermediate regions, a basic structure for the stray radiation grid is built up over the detector surface directly on the X-ray detector with a rapid prototyping technique and is subsequently coated or filled with a material that is highly absorbent for X-radiation. An absorbent structure thus arises that lies over the less sensitive intermediate regions of the detector surface. Moiré disturbances are avoided in the X-ray image exposure and the detective quantum efficiency (DQE) is increased.
Abstract:
In a solid-state radiation detector and a medical examination and/or treatment device having such a solid-state radiation detector, the detector has a pixel matrix, with each pixel supplying an output signal dependent on the incident radiation. The pixel matrix has a conversion layer that converts the incident radiation into charge, a storage capacitor for storing the charge and a transistor for reading out the charge. The capacitance of the storage capacitor is set to be so small that because of the voltage drop across the storage capacitor, the output signal of the pixel exhibits, starting from a specific value of the incident radiation dose, a sublinear response with reference to the radiation dose.
Abstract:
The invention is directed to an x-ray image intensifier having an evacuated housing, an input luminescent screen, electron optics, and an image sensor applied inside the housing at that side thereof lying opposite the input luminescent screen. The side of the image sensor facing toward the input luminescent screen is provided with a layer system that includes at least one semiconductor layer that effects an electron conversion of the incident electrons by ionization with charge carrier multiplication and is composed of amorphous semiconductor material.
Abstract:
A highly blocking diode structure having a thin film a-Si:H (amorphous silicon containing hydrogen) layer, suitable for use in constructing image sensor arrays, has two conductive electrodes disposed on opposite sides of the a-Si:H thin film layer. The structure is constructed on an electrically insulating substrate and includes a barrier layer disposed between the a-Si:H layer and the top electrode. The top electrode may consist of indium tin oxide or of palladium silicide, and the barrier layer may consist of silicon oxide produced by converting the surface of the a-Si:H layer. The barrier layer is disposed on that side of the a-Si:H layer opposite the substrate. The barrier layer significantly improves the behavior of the contacts and the stability of the boundary surface between the a-Si:H layer and the transparent metal oxide comprising the electrode. The sequence for constructing the diode arrangement is considerably simplifed.
Abstract:
In a focus detector arrangement and method for an x-ray apparatus for generating projection or tomographic phase-contrast images of an examination subject, a beam of coherent x-rays is generated by an anode that has areas of different radiation emission characteristics arranged in bands thereon, that proceed parallel to grid lines of a phase grid that is used to generate the phase-contrast images.
Abstract:
The invention relates to a device for protecting a display facility, comprising a protective element for covering an image surface of the display facility. As the protective element is designed to be transparent and the retaining means are provided for the exchangeable arrangement of the protective element in front of the image surface, a protective device is provided, which allows the image surface to be examined and is easy to operate.
Abstract:
In a medical imaging system and method, an image data acquisition system is operable in a fluoroscopy mode to obtain a fluoroscopic image of a subject and is operable in a CT mode to obtain projection data sets of the subject that are used to reconstruct a three-dimensional image of a region of interest of the subject. For imaging procedures involving the administration of contrast agent to the subject, the image data acquisition apparatus is operated in the fluoroscopy mode at the time the administration of contrast agent is begun, and the filling of vessels with the contrast agent is automatically monitored by fluoroscopy. When the automatic monitoring indicates that an optimal degree of filling of the vessels with the contrast agent has occurred, the image data acquisition apparatus is automatically switched to operate in the CT mode to acquire projection data sets of the region of interest containing the vessels filled with contrast agent.
Abstract:
A focus-detector arrangement of an X-ray apparatus is disclosed for generating projective or tomographic phase contrast recordings with a phase grating. According to at least one embodiment of the invention, in the gaps between its bars, the phase grating includes a filler material whose linear attenuation coefficient in the relevant energy range is greater than that of the bars. The height of the filler material in the gaps is dimensioned on the one hand so that the X-radiation with the energy used for measuring the phase shift generates a phase shift in the X-radiation such that, after the phase grating, the rays which pass through the bars are phase shifted by one half wavelength relative to the rays which pass through the gaps with the filler material. Further, the height of the filler material in the gaps on the other hand is dimensioned so that the attenuation of the X-radiation, at least in relation to the energy used for measuring the phase shift, is the same when passing through the bars and when passing through the filler material.
Abstract:
An x-ray absorption grid produced by a lithography method for use in a phase-contrast CT system has at least two individual grids arranged atop one another in the radiation direction. Each individual grid has a grid area with a grid structure including grid webs and grid gaps in alternation. Each individual grid has a region outside of the grid area (outer region). The outer region of the at least two individual grids has toothed structures corresponding to one another at least two points. The toothed structures are generated as well in the production of the grid structure. The toothed structures have a position that is defined relative to the grid structure, such that a defined alignment of the individual grids occurs given a combination of the individual grids by engagement of the toothed structures of individual grids lying atop one another.
Abstract:
A focus-detector arrangement of an X-ray apparatus is disclosed, for generating projective or tomographic phase contrast recordings of a subject. In at least one embodiment, least one grating of a focus-detector arrangement includes, at least partially, a macroscopically homogeneous medium which, when excited by an energy source, assumes a periodic structure/standing wave field that leads to beam splitting and the formation of an interference pattern when the X-ray beam passes through.