METHOD AND APPARATUS FOR CONTRAST EQUALIZATION OF AN X-RAY IMAGE

摘要

A method is described for contrast equalization of X-ray photographs made with an apparatus for slit radiography. A controllable absorption device (8) interacts with the slit diaphragm (2) to influence the fanshaped X-ray beam (3) per sector. The absorption device (8) is controlled (10) as a function of the quantity of radiation instantaneously transmitted (11) per sector through a body (7) in a manner such that the quantity of radiation transmitted in a particular sector through the absorption device is reduced with an increasing value of the transmission of the body occuring instantaneously in said sector from a first threshold value upwards. Above the threshold value, a higher transmission value results to a predetermined extent in an essentially higher quantity of radiation transmitted through the body, at least in regions of relevance for the X-ray photograph.