Analysis of the reproducibility of the gray values and noise of a direct digital radiography system

Abstract

Analysis of the reproducibility of the gray values and noise of a direct digital radiography system Abstract: The aim of this study was to evaluate the reproducibility of the gray values and noise of a direct digital radiography system (Visualix eHD) for various exposure times and analyzed regions. To obtain radiographic images in a standardized manner, the digital sensor of the system and a stepwedge were positioned in a phantom at a focus-film distance of 30 cm in a dental device at 70 kV, 7 mA and 2.2 mm filtration. Ten consecutive repetitions of X-ray imaging were performed at each exposure time (0.05, 0.07, 0.09 and 0.13 s). Gray values were analyzed using ImageJ software in five regions of interest (ROIs): alveolar bone (AB), soft tissue (ST) and three steps of the stepwedge (S1, S2 and S3). The results showed that both the variability of the gray values and the noise were statistically greater (p < 0.05) in the most radiolucent region (ST). Only the noise was affected by the exposure time. In conclusion, the reproducibility of the gray values and the noise of the Visualix eHD system can vary in specific areas with different radiolucency.

Analysis of the Gray-Value Reproducibility and Noise of a Direct Digital Radiography System

“…The digital radiograph represents a great advance in oral maxillofacial radiology because it incorporates informatics technology in the capture, interpretation, and archiving of radiographic images. Importantly, it eliminates technical, chemical processing errors and obviates the need for the conventional film, thereby reducing the production of environmentally toxic residues [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] .…”

“…However, the results obtained in such applications depend on radiograph system quality and exposure time. The physical and clinical outcomes of various radiograph systems have been evaluated [7][8][9]11,13,[18][19][20] .…”