35-MM FILM SCANNER AS AN INTRAORAL DENTAL RADIOGRAPH DIGITIZER .1. A QUANTITATIVE-EVALUATION

A 35-mm slide scanner digital imaging system was tested for its suitab ility in digitizing intraoral dental radiographic film for quantitativ e studies. The system (Nikon model LS-3510AF Nikon Electronic Imaging, Nikon, Inc., Melville, N.Y.) uses a charge-coupled device linear phot odiode array. The data content in the original film images was evaluat ed, and the system performance assessed objectively with the use of sp ecially designed test films. Radiometric and geometric performances fo r the digitizing system were extracted from measurements and observati ons, and these were compared with published data for two other film di gitizing systems (video camera DAGE MTI, Michigan City, Ind. and Barne yscan 35-mm film digitizer Barneyscan, Berkeley, Calif.). The techniqu es used to evaluate this system are easy and suitable for evaluation o f any digitizing system. This scanner system (Nikon) was superior to p reviously evaluated systems in transforming and recording radiographic film densities across the range (0.3 to 2.0 optical density units) of clinically relevant optical densities. The scanner offers substantial advantage over the other digitizing systems for gray scale informatio n from clinically important optical densities.