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

Autor: Marcelo Lupion POLETI, Thais Maria Freire FERNANDES, Renata Cordeiro TEIXEIRA, Ana Lúcia Alvares CAPELOZZA, Izabel Regina Fischer RUBIRA-BULLEN
Jazyk: angličtina
Rok vydání: 2015
Předmět:
Zdroj: Brazilian Oral Research, Vol 29, Iss 1, Pp 1-5 (2015)
Druh dokumentu: article
ISSN: 1807-3107
DOI: 10.1590/1807-3107BOR-2015.vol29.0062
Popis: 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.
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