Cost-effectiveness of stereoscopic radiographs in detection of lung nodules

Detection of lung nodules was assessed using a series of radiographs which were either normal or showed only one nodule. Stereoscopic pairs were obtained in 26 cases (10 positive and 16 normal). A "singles" series comprising one radiograph from each pair was presented to each observer on three occasions. The pairs were later presented side by side and finally were viewed stereoscopically. The results indicate that a second shifted radiograph improves detection of lung nodules enough to be cost-effective. The shifted radiographs do not need to be viewed stereoscopically.