Evaluation of a PC-based teleconferencing system for reading chest radiographs

Chest radiographs from 50 patients, including 25 with lung cancer, were digitized at a resolution of 100 dots/inch (40 dots/cm) and saved in JPEG format at a low compression ratio. The average size of the stored images was 55 kByte (range 6-86 kByte). Four respiratory specialists observed these images on the cathode ray tube (CRT) display of a PC-based teleconferencing system with a resolution of 800 x 600 pixels. One month later they observed the original chest radiographs. A receiver operating characteristic (ROC) analysis was performed on their diagnoses, based on a five-point confidence scale about the presence of lung cancer. The observer-specific Az values for the teleconferencing system ranged from 0.801 to 0.944, and the corresponding Az values for the conventional radiographs from 0.926 to 0.957. No significant differences were found between the teleconferencing images and the original images, which suggests that a PC-based teleconferencing system could be useful in the diagnosis of lung cancer on chest radiographs.