EVALUATION OF AN ENHANCED DIGITAL FILM-DUPLICATION SYSTEM BY RECEIVEROPERATING CHARACTERISTIC ANALYSIS

RATIONALE AND OBJECTIVES. Over- or underexposure often results in poor quality radiographs. Using receiver operating characteristic analysis , the authors investigated the potential utility of a system that corr ects densities in such images to improve the accuracy of lung nodule d etection. METHODS. Chest radiographs were digitized by a laser film di gitizer. Simulated nodules were superimposed on 36 improperly exposed chest radiographs. All images, with and without nodules, were then pro cessed by a nonlinear density-correction technique. Hard-copy images w ere produced by a laser film printer. Eight radiologists evaluated the corrected and uncorrected images for the presence or absence of lung nodules using a continuous (0-100) confidence-rating scale.