RESUMO
<p><b>OBJECTIVE</b>To compare the performance of full-field digital mammography (FFDM) and digital breast tomosynthesis (DBT) in the assessment of the lesions in dense breast, and to estimate the difference in diagnosis of breast disease by FFDM images alone and FFDM plus DBT images.</p><p><b>METHODS</b>According to the breast imaging reporting and data system (BIRADS), 134 patients were selected. The morphology of the lesions shown on FFDM and DBT were evaluated and compared, and the maximum diameter of the lesions was measured. At first, doctors made the diagnosis of a patient by reading FFDM only. Then they made another diagnosis by combining with DBT images of the same patient. The two diagnoses were compared and analyzed according to the pathology results.</p><p><b>RESULTS</b>One hundred and thirty-four patients were included in this study, and all of them were confirmed by histology (65 benign cases, 69 malignant cases). DBT could show more details about the morphology of the lesions, including the border of the masses, spiculation and vessels. The numbers of those signs detected by DBT were 46, 30 and 3, respectively, while only 33 case with circumscribed masses and 14 cases with spiculation were detected by FFDM. Only the difference of spiculation in heterogeneously dense breast detected by DBT and FFDM was statistically significant (P < 0.05). Of the cases with calcifications, DBT images (reconstructed as a 1-mm-thick slice) showed calcifications superior to FFDM in 2 cases, equal to FFDM in 23 cases, and inferior to FFDM in 11 cases. The difference was statistically significant (P < 0.05). But when thickness was changed into 1 cm, the visibility of calcifications in those cases was equal between FFDM and DBT. The maximum diameter of lesions was 2.46 ± 1.64 cm in DBT image, and 2.58 ± 1.62 cm in FFDM image, with a significant difference (P < 0.05). Comparing with reading FFDM images only, the accuracy of FFDM combining with DBT was increased from 88.8% to 91.8%. For FFDM, the AUC of ROC was 0.887, while for DBT it was increased to 0.912, with a non-significant difference (P > 0.05).</p><p><b>CONCLUSIONS</b>DBT is superior to FFDM in the morphological characterization and small calcification in the lesions in dense breast. Combining FFDM and DBT improves the accuracy of diagnosis, but the difference is not statistically significant.</p>