| 摘要 |
An x-ray diagnostics installation for subtraction angiography has an x-ray radiator which generates an x-ray beam that penetrates a patient, the resulting image being processed in an x-ray image intensifier video chain wherein the x-ray image is converted into a sequence of video signals for display. The video chain includes an image memory for storing the video signals and a difference-forming unit for subtracting the stored video signals from current video signals to form difference video signals. An image reproduction stage has various adjustment elements permitting variation of parameters identifying a region or a window of brightness values for reproducing the video signals on the display. By means of the adjustment elements, various image parameters, such as background brightness and darkening of the blood vessels, can be set independently of each other.
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