X-ray diagnostic apparatus comprising X-ray intensity and diaphragm value controls

摘要

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.