X-ray examination apparatus including a subtraction unit

Abstract

An X-ray examination apparatus includes an X-ray source (1) for irradiating an object (2) by means of an X-ray beam (3) in order to form an X-ray image. An optical image is derived from the X-ray image by means of an X-ray detector (4). The optical image is picked up by means of an image pick-up apparatus (5). The image pick-up apparatus (5) includes a plurality of image sensors (6, 7) for deriving separate electronic sub-image signals from the optical image. The image pick-up apparatus also includes a subtraction unit (8) for subtracting the electronic sub-image signals from one another. The image pick-up apparatus (5) also includes a control circuit (9) which is arranged to make integration periods of individual image sensors (7, 8) commence at instants which are spaced a waiting period apart. The difference signal represents changes in the X-ray image or, when the X-ray energy is changed during the waiting period, differences in X-ray absorption due to energy-dependency.

Dependencies are inferred from the claim text.