[Nodular lesions simulated on an anthropomorphic thoracic phantom. A comparison between analog and digital images of...

Aim of this work is to evaluate the diagnostic accuracy of different modalities of digital radiology, compared with conventional radiology, in the detection of lung nodules. Forty images of an anthropomorphic chest phantom, on which simulated nodules had been previously set, were analyzed by 6 radiologists with 4 different viewing modalities: a) conventional radiography; b) photostimulable plates digital radiography; c) photostimulable plates digital image on dedicated monitor; d) conventional radiography digitized with Film Laser Digitizer and viewed on Display Workstation. For each image the radiologists had to transfer on a sketch the site of the detected nodules giving an opinion on their detectability (uncertain-presumable-probable-certain presence) with a 1 to 4 score. The statistical analysis of the results was made using modified ROC curves. No statistically significant difference was found between the areas under a) and c) ROC curves (p = 0.262). A statistically significant difference resulted between the areas under a) and d) ROC curves (p < 0.05) and, particularly, between the a) and b) areas (p < 0.001), in favor of a).