X-ray image pick-up device.

摘要

(9 An X-ray image pick-up device includes an X-ray source (34) for radiating X-rays onto an object (32) including a region of interest, an image intensifier (36) for converting to an optical image an X-ray image obtained when the X-rays radiated from the X-ray source (34) are transmitted through the object (32), an image pick-up camera (40) for converting to an image pick-up signal the optical image which is generated from the image intensifier (36), and an optical diaphragm (38) arranged between the image intensifier (36) and the image pick-up camera (40) for adjusting an amount of optical image light incident on the image pick-up camera (40). The X-ray image pick-up device further includes an exposure controller (46) for detecting both the maximum value of image pick-up signals from the pick-up camera (40) and the average value of the image pick-up signals in the region of interest at a time of fluoroscopic examination, for calculating the density resolutions of the output pick-up signals from the image pick-up camera (40) with respect to the various combinations of tube voltages, tube currents and optical diaphragm values, and for determining a tube voltage and a tube current of an X-ray source (34), along with an optical diaphragm value so as to provide a maximum density resolution which permits the device to always operate under optimal exposure conditions.