Combining Shallow and Deep Neural Networks on Pseudo-Color Enhanced Images for Digital Breast Tomosynthesis Lesion Classification

Zhikai Yang^*Yingqing LiuÖrjan SmedbyRodrigo Moreno^*

• Department of Biomedical Engineering and Health, Royal Institute of Technology, Stockholm, Sweden

The classification of lesion types in Digital Breast Tomosynthesis (DBT) images is crucial for the early diagnosis of breast cancer. However, the task remains challenging due to the complexity of breast tissue and the subtle nature of lesions. To alleviate radiologists' workload, computer-aided diagnosis (CAD) systems have been developed. The breast lesion regions vary in size and complexity, which leads to performance degradation. To tackle this problem, we proposed a novel DBT Dual-Net architecture comprising two complementary neural network branches that extract both low-level and high-level features. By fusing different-level feature representations, the model can better capture subtle structure. Furthermore, we introduced a pseudo-color enhancement procedure to improve the visibility of lesions on DBT. Moreover, most existing DBT classification studies rely on two-dimensional (2D) slice-level analysis, neglecting the rich three-dimensional (3D) spatial context within DBT volumes. To address this limitation, we used majority voting for image-level classification from predictions across slices. We evaluated our method on a public DBT dataset and compared its performance with several existing classification approaches. The results showed that our method outperforms baseline models, showing the potential of the method for being implemented in the clinic. The code is available at https: //github.com/xiaoerlaigeid/DBT-Dual-Net.