Full-Field Digital Mammographic Interpretation With Prior Analog Versus Prior Digitized Analog Mammography: Time for Interpretation

OBJECTIVE: The purpose of our study was to quantitatively compare the time for interpretation of screening full-field digital mammography (FFDM) images using prior analog film mammograms for comparison versus digitized prior analog mammograms. MATERIALS AND METHODS: Images from 100 FFDM studies were interpreted by four radiologists. All FFDM images had comparison analog mammograms obtained a minimum of 1 year earlier that were digitized using a 43-μm film digitizer. Initially, the FFDM images were interpreted using the digitized prior mammogram on two, 5-megapixel monitors and PACS. All available PACS tools could be used. Four weeks later, the same 100 screening FFDMs were interpreted using the original analog mammograms on an alternator at 90° to the monitors used to interpret the screening FFDMs. The interpretation times were recorded and compared. The results were compared and evaluated for statistical significance using statistical software, with statistical significance set at p < 0.05. RESULTS: For each radiologist, the mean reading time for FFDM with digitized priors was significantly shorter in length in comparison with the mean reading time calculated for interpreting FFDM using analog film priors. The differences in times recorded between digitized analog versus analog ranged from 11.31 to 74.18 seconds. The reading times for the four readers ranged from 17.32 to 185.94 seconds, with a mean of 58.56 seconds when using analog film prior mammograms. When using digitized analog prior mammograms, the reading times for the four readers ranged from 11.32 to 109.11 seconds with a mean of 39.76 seconds. The average difference in reading time was calculated to be 18.80 seconds, showing that there is a 32% increase in interpretation speed when using a digitized prior analog for comparison studies as opposed to an analog prior. CONCLUSION: There is a statistically significant 32.1% average improvement in interpretation time when FFDM screening mammograms use digitized analog comparison mammograms than if FFDM is interpreted with the original analog film mammograms. This should allow more FFDMs to be interpreted in the same amount of time if digitized prior analog mammograms are used.