Abstract: A radiographic diagnostic apparatus for irradiating radiations to the subject for diagnosis, which comprises radiation generator section for irradiating radiations to the subject, detecting section for detecting radiations passing through the subject, and converting the detection results into image data, the image data containing first image data before catheter insertion and second image data after catheter insertion, extracting section for extracting the desired portion from the first image data, image synthesizing section for combining the portion extracted at the extracting section with either the first image data or the second image data and converting the overlapping areas in the resulting combined data into different data to form third image data, and display section for displaying the third image data obtained at the image synthesizing section.

Abstract: An X-ray diagnostic apparatus comprising an X-ray source for irradiating X rays to a patient, an image intensifier tube for converting an X-ray image, formed by transmitting X rays through the patient to an optical image, a television camera for receiving the optical image from the image intensifier tube through a diaphragm to output the video signal. In this pick-up apparatus, the X-ray source pre-irradiates one time a small dose of X-rays before main irradiation and there are provided a detector for detecting the maximum value of the video signal produced from the camera at the time of pre-irradiation, and an arithmetic operation circuit for calculating a diaphragm value from the maximum value detected and from pick-up conditions except a diaphragm value at the time of main irradiation of X rays in such a way that the maximum value of the video signal from the camera at the time of main irradiation becomes equal to the maximum permissible value of the camera.

Abstract: A diagnostic X-ray apparatus emitting pulsed X-ray radiation includes a processor for performing digital X-ray subtraction of a previous mask image from current images. The apparatus includes circuitry for digitization of the video signals from an image intensifier-TV chain, digital subtraction to obtain digital difference signals, and subsequent reconversion of the resultant digital difference video signals to analog signals. Pulsed X-ray exposures are performed during the blanking periods of the TV camera following which the television fields immediately following the pulsed X-ray exposure are scanned and read out, and are supplied to the processor for performing the digital X-ray subtraction.