Modern day emphasis on radiation dose minimisation possibly suggests a basic alteration in many diagnostic X-ray procedures. For statistical reasons, in an image one needs a certain minimum number of information carriers per unit area to differentiate structure. A multi-intensity image thus means that more than the necessary number of quanta have traversed some regions. A bright region, though the absorption is low, has absorbed more quanta than necessary. This is not true if feedback from an electronic detector to a scanning X-ray tube adjusts the generated intensity so that the flux emerging from the subject is everywhere the same. Such a method can bring the quantum flux at the critical level of lowest density along the path everywhere to the minimum acceptable value.