Background

Mammography is considered the most cost-effective screening method for the early detection of breast cancer. However, the sensitivity of mammography is often limited by the presence of overlapping dense fibroglandular tissue in the breast. Because a mammogram is a two-dimensional (2D) projection of the breast onto the detector plane, overprojected normal tissue (anatomical noise) can hamper breast cancer detectability. 

The purpose of our study was to compare the diagnostic potential of 2D digital mammography with tomosynthesis, when added to mammography, by evaluating their image quality and estimating their sensitivity values taking in consideration the ultrasound and/or histopathologic findings.

 Methods and materials

123 women- with ages ranging between 36 and 61 years (mean age of 48.5 years) with focal asymmetries were included. The mammography interpretation consisted of a direct comparison of full field digital mammography (FFDM) images with the tomosynthesis examination added to FFDM. The equivalence of the image quality of both the FFDM and the DBT with FFDM examinations was subjectively rated.  The next step was categorizing the findings separately according to BIRADS classification. Targeted ultrasonography (US) was performed to identify benign causes of the asymmetry or identify a target for biopsy. The findings were matched up to those of the ultrasound examinations and/or histopathologic results and the statistical analysis evaluated the p values of DBT and FFDM as well as their sensitivities.

Results

The image quality of tomosynthesis was subjectively rated as equivalent (43.1%) or superior (48%) to digital mammography in 91.1% of the total of findings; the test that this proportion was greater than 50% was highly significant (p < 0.001). Histological and sonographic imaging assessment in 123 findings yielded 31 malignant (25.2%) and 92 benign lesions (74.8%). The FFDM Sensitivity was of 80 % compared to 84.4% when DBT was added to FFDM.