摘要:
In a method for positioning a catheter that has been inserted into a vessel and a device for implementing the method, the road map technique is used, wherein as a mask image, a three-dimensional mask image of the vessel which is composed of number of individual mask images is employed. From these individual mask images, that individual mask image is selected whose exposure direction corresponds optimally to the exposure direction of an instantaneously captured individual image, in order to combine this selected individual mask image with the instantaneously captured mask image and to display the resulting combined image.
摘要:
A radiological system, wherein x-ray images (radiation images) are produced and are converted, through a video chain, for display as a video image, the system having a modulation transfer function, has the capability of influencing the modulation transfer function dependent on ambient light which is present at the display. To that end, a control unit is provided which provides two-dimensional control of the modulation transfer function dependent on illumination which is present in the environment of the display. The control is effected by means of a two-dimensional spatial frequency filter.
摘要:
An x-ray diagnostics installation having a primary radiation diaphragm disposed in the beam path of an x-ray tube includes a control unit for the primary radiation diaphragm having an operator-manipulable setting element and associated circuitry which cause the primary radiation diaphragm to move in directions corresponding to the direction of movement of the setting element. Rotary motion of the setting element causes rotation of the primary radiation diaphragm, and pivoting of the setting element cause the primary radiation diaphragm to be moved in the corresponding direction of the pivot.
摘要:
An x-ray diagnostics installation has an x-ray source fed by a high voltage supply, an x-ray image intensifier video chain for generating stored video signals of an exposure without a patient present in the x-ray beam, and a calculating stage connected to the memories. A filter is disposed in the path of the x-ray beam. The calculating stage is connected to the video chain and to the high voltage supply and calculates actual attenuation values of an x-ray exposure with the filter inserted in the x-ray beam.
摘要:
In an exemplary embodiment, an image intensifier television chain includes an X-ray image intensifier, an optical coupler, a television pickup tube, a central unit for controlling the scanning beam of the television pickup tube, and a video amplifier for the picture signal. Between the video amplifier and an image memory, which is controlled by the central unit, a switch is arranged which is controllable by a control device in such a manner that the storage of an image takes place following a specified number of scannings of the target of the television pickup tube.
摘要:
A medical radiological diagnostics system having an automatic exposure unit employs signal acquisition and a processing circuitry for controlling the radiation source so as to obtain easily diagnosed exposures with a low radiation load. This is accomplished by disposing a stray radiation grid between the radiation receiver and a radiation sensor, or by selecting the spacing between the radiation receiver and the radiation sensor such that scattered radiation is not incident on the radiation sensor, or, in a system having an x-ray image intensifier and a light sensor, by supplying the output signal of the light sensor to the control circuit through a high-pass filter. In all versions, the measured signal is not disadvantageously influenced by scattered radiation, so that a correct exposure of x-ray film is possible.
摘要:
An x-ray diagnostics installation has an x-ray image intensifier video chain which includes a semiconductor detector composed of pixels arranged in a matrix, serving as the video pick-up and a detector for identifying the average image brightness at the output luminescence screen of the x-ray image intensifier within a predetermined image region. A first read-out circuit is provided for pixels of a first group in the image, which is operated with a read-out clock at a first frequency, and a second read-out circuit is provided for pixels of a second group distributed over the area of the semiconductor detector, which is operated with a read-out clock at a second frequency. The second frequency is higher than the first frequency. The output signals of the pixels of the second group are supplied to an evaluation circuit, and the output signals of the first group of pixels are supplied to the video chain. Image production parameters, such as image brightness, can be controlled on the basis of the output signals of the second group of pixels.
摘要:
An x-ray diagnostics installation includes an x-ray tube, a variable aperture diaphragm, and an x-ray image intensifier video chain which includes an x-ray image intensifier, a video pick-up unit, a processing circuit, and a playback unit. The variable aperture diaphragm has a central region and an outer region which exhibit different x-ray transparencies. When adjusted to a first position, the aperture diaphragm permits x-rays to pass only through said central region unattenuated. The aperture diaphragm is adjusted to a second position for every n.sup.th image, wherein both the central region and the outer region permit x-rays to pass through the diaphragm unattenuated. Each n.sup.th image is entered into an image memory connected to the video pick-up unit and is superimposed on an image produced when the diaphragm is in the first position.
摘要:
An x-ray examination apparatus includes a position-adjustable x-ray tube, a patient support, and a position-adjustable image pick-up system, the image pick-up system including an x-ray image intensifier and a video camera coupled thereto. The output of the video camera is shown on a display monitor. Signals identifying the position of the x-ray tube and the image-pick-up system relative to a patient are supplied to a computer, which calculates angular deviation of those components from a desired reference. Signals corresponding to any such deviations are supplied to the horizontal and vertical sawtooth voltage generators for the video camera, so that scanning of the target of the video camera is always undertaken perpendicularly relative to the reference, independently of movement of the image pick-up system.
摘要:
A stereoscopic x-ray tube has an evacuated housing with a motor-driven anode dish therein, as well as at least two cathodes. The cathodes are disposed for directing electrons onto two respective foci within at least one track of the anode dish. Each of the foci generates a beam of useful x-rays, the two beams alternating. The anode dish is divided into at least one pair of segments of identical size, each segment emitting x-rays of a different intensity, so that only one segment in each pair can emit useful x-rays. The cathodes are disposed such that their respective foci are spaced at an uneven multiple of the length of the track within a segment.