[Possibilities of dose reduction in extramammographic xeroradiography (author's transl)].

The soft radiation within the inhomogeneous spectrum of bremsstrahlung, being unable to penetrate the object and not contributing to the build-up of the xeroradiographic picture, only being the cause of additional radiation exposure, is considerably reduced by means of added filters, copper filters in particular. This effect can be demonstrated qualitatively by means of the recorded X-ray spectra. In comparison with the standard record it is possible by hardening of the radiation to reduce the surface dose by a factor 8 at a tube voltage of 120 kV, and by a factor 10 at a tube voltage of 130 to 150 kV if a 0.5 mm thick copper filter is added. The surface dose measured with high-filtration in xeroradiography is within the same order of magnitude as the dose obtained with a conventional film-foil-combination (Cronex 4/Cawo high-definition foil, 75 kV, automatic exposure control, time of development 90 s) and amounts to circa 0.1 R. A loss of information in so-called high-filtration xerograms as compared to conventional xerograms could be excluded, at least with regard to the test object. The practicability of this method e.g. for angiography, particularly angiographic exploration of the limbs, needs further clinical examination.