Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
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.
Abstract:
An X-ray diagnostics installation has an X-ray source and an X-ray image intensifier video chain, including an X-ray image intensifier, a video camera, a control circuit that derives control pulses for producing images of a subject from data supplied thereto identifying exposure conditions, and a subtraction circuit for forming the difference between stored video signals and continuing, current video signals given the same exposure conditions. The X-ray source is cyclically moved during the production of a number of successive images, with the control circuit deriving the control pulses for the production of images from apparatus positions and, possibly, from the ECG of the subject. The subtraction circuit forms the difference between predetermined video signals stored for different apparatus positions and heart phases of a heart cycle and continuing, current video signals obtained at the same apparatus positions and at the same heart phase.
Abstract:
An x-ray diagnostics installation has an x-ray source connected to a parameter setting unit which sets exposure parameters (operating characteristics) of the x-ray source, and an x-ray image intensifier video chain. The x-ray image intensifier video chain includes a processing circuit connected to a video pick-up stage and a motion detector. The processing unit controls the parameters of a filter unit for chronological filtering of the video signal. The motion detector is connected to the parameter setting unit for the x-ray source, and controls the filter unit depending on the exposure parameters which are set for a given exposure, such as the level of the video signal, the tube voltage, the radiation dose, and the imaging format of the x-ray image intensifier, all of which are set at the parameter setting unit and which characterize the exposure.
Abstract:
An x-ray diagnostics installation has an operating voltage generator, an x-ray tube, an x-ray image intensifier, a video camera, a video amplifier having controllable gain, an integration circuit and a control circuit that acts on the operating voltage for dose rate control. The x-ray diagnostics installation is fashioned such that the control circuit is connected to the video amplifier and to the integration circuit and controls these components such that the gain of the video amplifier is raised when a limit value of the dose rate control is reached, with parameters of the integration circuit being simultaneously modified.
Abstract:
In a radiological installation comprising an image pick-up system having a memory for individual images and having an image playback unit, an overall image formed of at least two individual images is capable of being portrayed, the number of lines thereof being at least largely independent of the sum of the number of lines of the individual images. For that purpose, the overall image is compiled line-by-line with a processor controller such that respectively one row of stored picture elements of an individual image forms a section of one line of the overall image, and a corresponding row of stored picture elements of at least one further individual image respectively adjoins this section.
Abstract:
The disclosure relates to an x-ray diagnostic installation comprising an x-ray image intensifier television chain, whereby a television camera is coupled via an optics with a base lens and a camera lens to the x-ray image intensifier, a mirror being disposed in the parallel ray path of said optics for coupling a portion of the luminous flux to a light detector, wherein an additional lens is arranged between the mirror and light detector. The light detector is comprised of a matrix of photosensors whose respective outputs are connected via respective switches to a sum amplifier.
Abstract:
An exemplary embodiment comprises an x-ray tube, an x-ray image intensifier, a television camera, a photographic camera, and a monitor system, which includes a video amplifier, a synchronizing pulse separation stage, a horizontal and a vertical deflection stage, a blanking stage and a picture tube with a deflection unit. The monitor system is provided with a pulse stage for the purpose of generating trace unblanking pulses for the formation of bright horizontal and/or vertical bars bounding the displayed image at the border of the picture tube, which pulse stage is connected with the synchronizing pulse separation stage. The photographic camera is so designed that the displayed images are adjacently photographed so as to avoid light transmitting interstices between the photographed images on the x-ray negative.