Freitas Patrícia, Yaedú Renato Yassutaka Faria, Rubira-Bullen Izabel Regina Fischer, Escarpinati Maurício, Vieira Marcelo Costa, Schiabel Homero, Lauris José Roberto
Department of Stomatology, School of Dentistry at Bauru, University of São Paulo.
Braz Oral Res. 2006 Jul-Sep;20(3):207-13. doi: 10.1590/s1806-83242006000300005.
The objective of the present study was to determine the reproducibility of the pixel values obtained with the Digora system (Soredex, Finland). Exposures were standardized, with variation in exposure and scanning time of two photostimulable phosphor plates containing a stepwedge image. The smallest variation in pixel values ranged from 50 to 75%, with the widest variations being observed in less dense steps. A significant difference in pixel values was observed in terms of X-ray exposure and scanning times and between the two plates themselves (ANOVA, p < 0.01). Using the present methodology, the reproducibility of pixel values was not satisfactory for the tested white photostimulable plates. This wide variation in digitalization might be influenced by the amount of X-rays that sensitized the plates. It may be important to establish the reproducibility of the pixel values in quantitative studies using digital image.
本研究的目的是确定使用Digora系统（芬兰Soredex公司）获得的像素值的可重复性。对曝光进行了标准化，两块含有阶梯楔形图像的光激励荧光板的曝光和扫描时间存在变化。像素值的最小变化范围为50%至75%，在密度较小的阶梯中观察到的变化最大。在X射线曝光和扫描时间方面以及两块板之间观察到像素值存在显著差异（方差分析，p < 0.01）。使用目前的方法，对于测试的白色光激励板，像素值的可重复性并不令人满意。这种数字化过程中的广泛变化可能受到使板感光的X射线量的影响。在使用数字图像的定量研究中确定像素值的可重复性可能很重要。
