ROC analysis of storage phosphor radiography and digital selenium radiography at various tube voltages in simulated chest lesions

Current digital radiographic systems are rapidly growing in clinical applications. The purpose of this study was to evaluate the diagnostic performance of storage phosphor radiography and digital selenium radiography (DSR) at different tube voltages in the detection of simulated chest lesions. Patterns of simulated interstitial lung disease, incipient infiltration, and nodules were superimposed over an anthropomorphic chest phantom. A simulated chest phantom radiograph was obtained with storage phosphor radiography and DSR at different tube voltages (70 kV, 90 kV, and 120 kV). A total of 18,000 observations were analyzed using a receiver operating characteristic (ROC) analysis. The detection of all lesions showed higher Az values at 70 kV than 120 kV with storage phosphor radiography. For the DSR, mean Az values at 70 kV were higher than other tube voltages not all lesions but for micro-nodule interstitial lung disease, linear interstitial lung disease, and incipient infiltration. However, these results were not significantly different (P ≫ .05). Based on these results, a clinical study should be performed to judge the use of suitable kV according to the type of detector system and lesions.