Rubia-Bullen Izabel Regina Fischer, Escarpinati Maurício Cunha, Schiabel Homero, Vieira Marcelo Andrade da Costa, Rubira Cássia Maria Fischer, Lauris José Roberto Pereira
Department of Stomatology, Bauru School of Dentistry, University of São Paulo, Bauru, SP, Brazil.
J Appl Oral Sci. 2007 Feb;15(1):14-7. doi: 10.1590/s1678-77572007000100004.
This study applied a simple method to evaluate the performance of three digital devices (two scanners and one digital camera) using the reproducibility of pixel values attributed to the same radiographic image.
Using the same capture parameters, a radiographic image was repeatedly digitized in order to determine the variability of pixel values given to the image throughout the digitization process. One coefficient value was obtained and was called pixel value reproducibility.
A significant difference in pixel values was observed among the three devices for the digitized images (ANOVA, p<0.00001). There was significant pixel value variability at the same digitization conditions for one scanner and the digital camera.
Digital devices may assign pixel values differently in consecutive digitization depending on the optical density of the radiographic image and the equipment. The pixel value reproducibility was not satisfactory as tested for two devices. It is maybe advisable knowing the digitization variations regarding pixel values whenever using digital radiography images in longitudinal clinical examinations.
本研究应用一种简单方法，通过同一射线图像像素值的可重复性来评估三种数字设备（两台扫描仪和一台数码相机）的性能。
使用相同的采集参数，对一张射线图像进行重复数字化，以确定在整个数字化过程中赋予该图像的像素值的变异性。获得了一个系数值，称为像素值可重复性。
对于数字化图像，在这三种设备之间观察到像素值存在显著差异（方差分析，p<0.00001）。对于一台扫描仪和数码相机，在相同数字化条件下存在显著的像素值变异性。
数字设备在连续数字化过程中可能会根据射线图像的光学密度和设备不同而赋予不同的像素值。经测试，两种设备的像素值可重复性并不令人满意。在纵向临床检查中使用数字射线图像时，了解像素值的数字化变化可能是明智的。
