FILM-SCREEN SYSTEMS - SENSITOMETRIC COMPARISON OF KODAK-EKTAVISION SYSTEM TO KODAK-T-MAT RA SYSTEM/

Background. In 1995, Eastman Kodak Company (Rochester, N.Y.) marketed the Ektavision Extraoral Imaging Film and Screen System. It produced h igh-resolution images by keeping the light emitted by intensifying scr eens from ''punching through'' one emulsion layer on the film to anoth er. Objectives. The objectives of the experiment were (1) to compare t he sensitometric properties of the Ektavision system to its predecesso r, the T-Mat/RA system and (2) to determine whether films and screens of the Ektavision and the T-Mat/RA systems could be interchanged witho ut clinically changing the sensitometric properties. Ektavision and La nex Regular intensifying screens were used in combination with Ektavis ion, T-Mat G/RA, T-Mat L/RA, and T-Mat H/RA films. Results. The result s showed that the Ektavision film was slightly slower than the T-Mat G /RA film no matter what type of screen was used. The type of screen us ed had little effect on inherent contrast or exposure latitude. The Ek tavision film had approximately similar inherent contrast as the T-Mat G/RA film but less than that of the T-Mat H/RA film; its latitude was less than that of the T-Mat L/RA film. The manufacturer does not reco mmend combining T-Mat/RA film with Ektavision screens or Lanex Regular screens with Ektavision film because of a possible reduction in image resolution. But this mismatch did not clinically affect inherent cont rast and exposure latitude; however, film speed was slightly affected. Conclusions. The Ektavision system is the result of advanced technolo gy that produces images of high resolution. The high-resolution Ektavi sion film is slightly slower than the T-Mat G/RA film but is equivalen t to it in its contrast and latitude. Therefore when changing from the combination of T-Mat/RA film plus Lanex Regular screens to that of Ek tavision film plus Ektavision screens, a slight increase in x-radiatio n exposure should be made.