Evaluating a CCD film digitizer: Comparing interpretation accuracy with original film readings

The purpose of the study was to determine if there were differences between the interpretations of radiographic images resulting from digitizing films using a recently developed CCD unit, and the readings of the original films. The general hypothesis to be tested was that there were no significant differences in the measures of accuracy, sensitivity, specificity and ROC analyses when the interpretations related to the two modes were compared. The authors selected 120 radiographic examinations for the study from departmental teaching files, which included chest, abdomen, extremity and other cases that were considered difficult to interpret. The authors also selected six specific abnormalities visualized on 60 of the cases as "true positives" to classify the reports. After anonymizing the patient identification, the films were digitized and independently interpreted by four board-certified radiologists. Each reader read all of the examinations, half on film alternators and the other half on a high-resolution soft-copy workstation. No reader interpreted the same examination more than once. As of this date, the preliminary results indicate that the hypothesis will be accepted, but more analyses of the data must be performed to confirm the early findings. The additional work will include complete verification of data entry and classification of interpretations, a detailed review of perceived image quality and completion of the ROC analysis by pairs of readers. If the results are confirmed, radiologists, other physicians and administrators will have another reliable option to conventional film practice through increased access to remote primary diagnosis and consultation using highspeed telecommunication media.