Prediction of Entrance Surface Dose in Chest Digital Radiography

Abstract

The purpose of this study is predicted easily the entrance surface dose (ESD) in chest digital radiography. We used two detector type such as flat-panel detector (FP) and IP (Imaging plate detector). ESD was measured at each exposure condition combined tube voltage with tube current using dosimeter, after attaching on human phantom, it was repeated 3 times. Phantom images were evaluated independently by three chest radiologists after blinding image . Dose-area product (DAP) or exposure index (EI) was checked by Digital Imaging and Communications in Medicine (DICOM) header on phantom images. Statistical analysis was performed by the linear regression using SPSS ver. 19.0. ESD was significant difference between FP and IP(85.7 μGy vs. 124.6 μGy, p=0.017). ESD was positively correlated with image quality in FP as well as IP. In FP, adjusted R square was 0.978 (97.8%) and linear regression model was ESD=0.407+68.810×DAP. DAP was 4.781 by calculating the DAP=0.021+0.014×340 μGy.In IP, adjusted R square was 0.645 (64.5%) and linear regression model was ESD=-63.339+0.188×EI. EI was 1748.97 by calculating the EI=565.431+3.481×340 μGy. In chest digital radiography, the ESD can be easily predicted by the DICOM header information.