1K versus 2K monitor: a clinical alternative free-response receiver operating characteristic study of observer performance using pulmonary nodules

The aim of this study was to investigate whether and how observer performance in detecting pulmonary nodules is influenced by the use of 1K and 2K monitors with and without voluntary postprocessing. The study was conducted with clinical digital chest radiographs of 48 patients. CT images of the same patient group served as the gold standard. Data on four different monitor conditions (1K overview, 2K overview, 1K with postprocessing, and 2K with postprocessing) were collected using a 6-point confidence-rating scale and interpreted with an alternative free-response receiver operating characteristic. When magnification and window settings were applied on the 1K monitor at the expense of an increased interpretation time, observer performance with the 1K monitor was not significantly different from that with the 2K monitor. A significant difference only occurred between the 1K monitor postprocessing condition and the 1K monitor overview condition. Considering diagnostic accuracy, the 1K monitor is sufficient for the detection of pulmonary nodules, provided that postprocessing options--especially magnification--are applied. Further comparative monitor studies on the detectability of other abnormalities (e.g., fine interstitial structures) need to be performed.