Supplemental breast US or DBT is an essential additive tool for screening strategies in women at average or intermediate risk of developing breast cancer. However, early comparative studies have shown that breast US may have a benefit over DBT in women with extremely dense breasts [9].
Endo et al. [8] and Teertstra et al. [10] evaluated the diagnostic performance of digital breast tomosynthesis and full-field digital mammography and both concluded that tomosynthesis can be used as an additional technique to mammography in patients referred with an abnormal screening mammogram or with clinical symptoms.
A comparison of digital breast tomosynthesis and ultrasonography regarding the characterization of breast lesions was the goal of Kim et al. [11]. Results showed that digital breast tomosynthesis may provide similar reader lesion characterization performance to that of the US for breast lesions depicted on the mammogram.
On the other hand, several studies focused on automated ultrasound.
Chang et al. [12] retrospectively evaluated the detection performance of benign and malignant breast masses using 3D volume data obtained by ABUS with results showed higher performance of ABUS in the detection of malignant, large, irregular shaped masses with surrounding changes, than benign, small, or round/oval masses without surrounding changes.
Giuliano et al. [13] study performed in 3418 asymptomatic women with mammographically dense breasts justified the cost-benefit of implementing the use of ABUS in conjunction with mammography in the dense breast screening population study.
This study compared the diagnostic performance of automated three-dimensional (3D) breast ultrasound (US) systems and breast tomosynthesis as diagnostic tools in the work-up of mammographically detected positive findings in dense breasts.
According to the BIRADS lexicon criteria for describing malignant masses and as regards the shape, 17 masses were irregular on both modalities and were proved to be malignant, yet tomosynthesis underestimated one case since it gave the appearance of a rounded mass (normally to a benign descriptor); however, fine speculation were identified on automated ultrasound images and core biopsy proved the malignant nature of this lesion.
We found out that the sensitivity of tomosynthesis regarding the characterization of the shape of malignant masses was 69.6% while it was 87% for automated ultrasound
Regarding the margins, and as expected, 78.6% of the circumscribed masses were benign and 65% of the spiculated masses were malignant. However, two masses were circumscribed on both modalities yet pathology proved them malignant, this confirms the idea that a single criterion is not enough for radiologists to reach a correct diagnosis. Tomosynthesis was as sensitive as automated ultrasound in this study both 65.2%.
Regarding the number of masses detected multiple lesions in 14 out of 19 cases with multiple masses, while automated ultrasound was able to detect the whole 19 cases.
Tomosynthesis was able to detect the extension of the mass by 43% while automated ultrasound by only 32.4%.
Tomosynthesis was far better in the detection of calcification; where 16 cases were detected by tomosynthesis while automated ultrasound was only able to detect 2 cases. This is one of the situations where tomosynthesis is definitely superior over automated ultrasound. Tomosynthesis was high more sensitive in the detection of calcification than automated ultrasound matching results by Hussein et al. [14].
In detection and characterization of different breast masses sensitivity, specificity, PPV, and NPV of ABUS were 100%, 75%, 84%, and 100%, respectively, and in breast tomosynthesis were 100%, 81.25%, 87.5%, and 100%, respectively.
Few studies have compared both modalities as that done by Hussein et al. [14] showing sensitivity, specificity, PPV, and NPV of ABUS was 92%, 98%, 92%, and 98%, respectively, and in BT were 92%, 92%, 76%, and 98%.
In this study, both modalities showed a higher sensitivity for the detection of breast masses both being 100% compared to 92% in Hussein et al. study [14] but less specificity for both modalities in this study with BT showing higher specificity compared to ABUS.