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RGO.Revista Gaúcha de Odontologia (Online)

On-line version ISSN 1981-8637

Abstract

GOMES, Adele Verônica Tonietto et al. Radiographic analysis of pixel intensity with aluminum step-wedge and different spatial resolutions. RGO, Rev. gaúch. odontol. (Online) [online]. 2012, vol.60, n.4, pp. 485-490. ISSN 1981-8637.

Objective To evaluate the pixel intensity and to compare it with different spatial resolutions, using an aluminum step-wedge. Methods The sample consisted of three bone chips of two dry pig mandibles. Then, each bone chip and the aluminum step-wedge were placed on periapical radiographs in order to take the images with Ekta Speed film, with an exposure time of 0.2 seconds and focal length of 25 cm. All radiographs were scanned with spatial resolutions of 150 and 300 dpi and saved as JPEG files. The images were measured using the histogram tool provided by the Image Tool program (UTHSCSA, Texas, USA) selecting specific areas on the bone chips and on the aluminum step-wedge. Results The data were analyzed by ANOVA and Tukey statistical tests which showed that there was no significant difference in pixel intensity between bone chips and step 3 (3.6 mmEq/Al) of the aluminum step-wedge (p>0.05). It was also observed that there were no significant differences in pixel intensity value measured on step-wedges 2 (3.3 mmEq/Al), 3 (3.6 mmEq/Al), 4 (3.9 mmEq/Al) and on the bone chips, between spatial resolutions of 150 and 300 dpi. Conclusion Small differences in spatial resolution did not interfere with the evaluation of pixel intensity. It is recommended to measure pixel intensity on digitalized radiographs using an aluminum step-wedge as a reference density value.

Keywords : Evaluation.; Radiography dental digital.; Radiographic image enhancement..

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