Evaluate the influence of monochrome display on the detection of pulmonary nodules based on ROC theory.

Objective Evaluate the influence of medical monochrome liquid crystal display(LCD)with different resolutions on the detection of pulmonary nodules. Methods Ninety-three direct digital radiography(DR)chest images were selected on-line from picture archiving and communication system (PACS),including 38 positive,32 suspected and 23 normal cases. All of the images were confirmed by CT. These positive images were divided into group A and B according to the diameter of nodules. Three experienced radiologists blindly read the 93 images using three types of displays with different resolutions. Regarding the presence of nodule,five-point confidence system was used:definitely absent,probably absent,indefinite,probably present and definitely present. All observers marked their confidence levels of each image according to the presence of pulmonary nodule on different displays. Software SPSS 13.0 was employed for statistical analysis. Results In the group-A cases,the areas under ROC curves were 0.643,0.686 and 0.739,and in the group-B cases,those were 0.813,0.832 and 0.846 respectively. There was no difference in the detection efficacy among different radiodiagnostic systems. Conclusion Regardless of post-processing tools,it was equivalent to detect pulmonary nodules with different diameters of Group A or B among medical monochrome LCDs with different resolutions.