Full-field digital mammography: Dose-dependent detectability of simulated breast lesions

Objectives: The study compares contrast-detail and microcalcification detec tability of a full-field digital mammography (FFDM) to a state-of-the-art c onventional screen-film mammography (SFM) by using different doses in the d igital system. Materials and Methods: The investigations were performed wit h an FFDM (Senographe 2000 D, GEMS) and an SFM system (Senographe DMR, GEMS ) using a contrast-detail mammography phantom (CDMAM) and an anthropomorphi c breast phantom with superimposed microcalcifications. The digital detecto r was exposed with standard dose of SFM and with a dose reduction of up to 75%. Contrast-detail curves and correct observation ratio (COR) were perfor med for the CDMAM phantom. ROC analysis with a confidence level ranging fro m 1 to 5 was done with the results of the anthropomorphic phantom. Results: Digital mammography with the same dose revealed at least an equivalent or even higher detectability rate than conventional mammography, COR could be increased at about 10-25%. The ROC analysis yielded better results for the FFDM system. The same lesion detectability in digital mammography as in the conventional method was reached at a dose reduction of about 25%, concerni ng spot views even at higher reduction. Dose reduction in the anthropomorph ic phantom resulted in a linear loss of detectability. The same detectabili ty as in conventional mammography was reached, however, by a dose reduction of about 50%. Conclusion: The results suggest that FFDM is at least equiva lent to or - as far as spot views are concerned - superior to conventional SFM concerning the detectability of simulated lesions. Thus, a potential of dose reduction is suggested.