Effects of geometric and screen-film unsharpness in conventional and 350-kVp chest radiography.
Clinical comparison of 350- and conventional 120-kVp techniques indicates that small linear structures, such as small pulmonary blood vessels, are shown better at 120 kVp, due in part to two factors affecting image unsharpness: geometric and screen-film unsharpness. The combined effects of geometric (Ug) and screen-film unsharpness were evaluated for both kVp levels. The total-system modulation transfer function (MTFUg X MTFscreen-film) demonstrates differences in unsharpness under two conditions: (a) when the same screen-film system is used with different magnifications (i.e., extreme planes in the chest) and (b) when different screen-film systems are used for magnification of the midplane of the chest.
D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D013902:Radiography, Thoracic / Q000295:instrumentation* / Q000379:methods