title: Digital and conventional chest imaging: a modified ROC study of observer performance using simulated nodules.
abstract: A modified receiver operating characteristic (ROC) study was performed in which five readers were asked to locate multiple nodules on images of an anthropomorphic phantom obtained with a prototype digital radiographic chest unit and with a conventional chest unit. Results indicate that when nodules were projected over the lungs, a significantly greater number (significant at the 5% level) were identified on conventional radiographs, whereas for nodules projected over the mediastinum, the digital images were notably superior (difference significant at the 2% level). An error analysis of the multiple nodule problem and pseudo-ROC curves are presented. The modified ROC study does not suffer from the positional ambiguity inherent in most ROC studies and is efficient in acquiring data.
mesh_terms: D000703:Analog-Digital Conversion; D003626:Data Display; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008171:Lung Diseases / Q000000981:diagnostic imaging*; D008953:Models, Anatomic; D011856:Radiographic Image Enhancement; D013223:Statistics as Topic