Diagnostic performance of digital breast tomosynthesis and full-field digital mammography with new reconstruction and new processing for dose reduction.

BACKGROUND: The main barrier to adoption of digital breast tomosynthesis (DBT) plus full-field digital mammography (FFDM) is radiation exposure dose. The purpose of this study was to evaluate the diagnostic performance of DBT plus FFDM, both with newly developed technology (nd), at a dose comparable to that of the conventional FFDM alone. METHODS: Nine hundred and thirteen participants were recruited from May 2014 to January 2016 consecutively. For each subject, the exposure setting for DBT(nd) + FFDM(nd) was also used for the conventional FFDM alone. Retrospective reader studies were performed: DBT(nd) + FFDM(nd) (142 cases, including 42 cancer cases) and conventional FFDM (258 cases, including 87 cancer cases). Eight radiologists provided Japanese categorizations and probability of malignancy independently. Diagnostic performance was assessed by comparing sensitivity, specificity, and area under the receiver operating characteristic curve (AUC). Two-sided P values were calculated. RESULTS: DBT(nd) + FFDM(nd) showed sensitivity and AUC significantly increased over the conventional FFDM (85.4 vs. 80.3%, P = 0.015 and 90.9 vs. 88.3%, P = 0.049) and specificity did not significantly increase (89.6 vs. 88.4%, P = 0.52). The mean glandular dose (MGD) difference of DBT(nd) + FFDM(nd) and conventional FFDM was not significant (difference - 0.11 mGy, P = 0.08). CONCLUSIONS: In this study population, DBT plus FFDM, both with newly developed technology, provided diagnostic performance improved over the conventional FFDM alone, even at comparable MGD.

Detectability comparison of modes in dual-mode digital breast tomosynthesis.

BACKGROUND: The objectives of this study were: (1) to evaluate the detectability of full-field digital mammography (FFDM) plus dual-mode digital breast tomosynthesis (DBT) and compare it with that of FFDM alone and (2) to compare the detectability of high-resolution-mode (HR mode used with 40°-angle imaging, 100-µm pixel size, and higher dose) DBT with that of standard-mode (ST mode used with 15°-angle imaging, 150-µm pixel size, and lower dose) DBT for diagnostic evaluation. MATERIALS: The local Institutional Review Board approved this retrospective study of two different sets of cases. All participants gave written informed consent. FFDM and DBT images of 471 women who were recalled were acquired between August 2013 and October 2014. HR mode and ST mode were applied to 155 breasts and 157 breasts, respectively. The cases of both modes were selected randomly. Eight radiologists interpreted the images. The detectability for recall cases and for follow cases, and area under the receiver operating characteristic curve (AUC) were calculated. RESULTS: Adding DBT to FFDM significantly increased the detectability for recall cases and AUC relative to those of FFDM alone (HR mode 8.9 %; 95 % confidence interval (CI) 5.7, 15.0 %; P = 0.013 and 4.9 %; 95 % CI 2.1, 7.7 %; P = 0.001; ST mode 8.3 %; 95 % CI 4.1, 12.1 %; P = 0.007 and 2.9 %; 95 % CI 0.5, 5.3 %; P = 0.02), whereas the detectability for follow cases did not significantly differ. The AUC increase was significantly higher in HR mode than in ST mode (1.5 %; 95 % CI 0.5, 3.7 %; P = 0.023). CONCLUSION: Adding HR-mode or ST-mode DBT to FFDM significantly improved the detectability for diagnostic evaluation case.