title: [Signal to noise ratio or the number of perceptible gray tones in the x-ray picture. I. The dependence on the system sensitivity S (DIN 6867)].
abstract: It is shown that the number of contrasts which can be differentiated on a radiograph depends on the detail size, the noise, and the viewing conditions. The minimum signal-to-noise ratio (SNR) for a perception approach is equivalently described by the SGA value. This testing method was first developed by De Belder and Bollen to examine the visibility of low contrast details. The correlation between the SGA and the speed class S of the system can be explained by this method.
authors.affiliation: Agfa-Gevaert, V-Roe-Wiss, Leverkusen.
authors.forename: C
authors.initials: C
authors.lastname: Blendl
authors.forename: M
authors.initials: M
authors.lastname: Kierdorf
authors.forename: R
authors.initials: R
authors.lastname: Bollen
authors.forename: K H
authors.initials: KH
authors.lastname: Freytag
mesh_terms: D005858:Germany; D006801:Humans; D011859:Radiography / Q000592:standards*; D012680:Sensitivity and Specificity; D014963:X-Ray Intensifying Screens
vernacular_title: Signal-Rausch-Verhältnis bzw. Anzahl wahrnehmbarer Graustufen im Röntgenbild. Teil I: Die Abhängigkeit von der Systemempfindlichkeit S (DIN 6867).