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

Chest radiographs from 50 patients, including 25 with lung cancer, were dig itized at. a resolution of 100 dots/inch (40 dots/cm) and saved in JPEG for mat at a low compression ratio. The average size of the stored images was 5 5 kByte (range 6-86 kByte). Four respiratory specialists observed these ima ge on the cathode ray tube (CRT) display of a PC-based teleconferencing sys tem with a resolution of 800 x 600 pixels. One month later they observed th e original chest radiographs. A receiver operating characteristic (ROC) ana lysis was performed on their diagnoses, based on a five-point confidence sc ale about the presence of lung cancer. The observer-specific A(z)values for the teleconferencing system ranged from 0.801 to 0.944, and the correspond ing A(z)values for the conventional radiographs from 0.926 to 0.957. No sig nificant differences were found between the teleconferencing images and the original images, which suggests that a PC-based teleconferencing system co uld be useful in the diagnosis of lung cancer on chest radiographs.