title: [Extrafocal radiation of medical x-ray tubes with a rotating anode].
abstract: A method for measuring the fraction of extrafocal radiation in the x-ray output of x-ray tubes was developed and tested under clinical conditions. A fraction of 10% was found, that increases with tube voltage and field size, while tube current and focal spot size have no influence. As a measure for the influence of off-focus radiation on image quality the contrast transfer function was used. Off-focus radiation causes detectable geometric unsharpness. If screen-film-systems are used, the unsharpness is negligible compared with the screen unsharpness. Ways for reducing off-focus radiation from medical x-ray tubes are discussed.
authors.affiliation: Institut für Röntgendiagnostik, Humboldt-Universität, Berlin, DDR.
authors.forename: R
authors.initials: R
authors.lastname: Juran
authors.forename: R
authors.initials: R
authors.lastname: Hinz
mesh_terms: D006801:Humans; D011859:Radiography / Q000295:instrumentation*; D013679:Technology, Radiologic
vernacular_title: Zur extrafokalen Strahlung von medizinischen Röntgenröhren mit Drehanode.