To facilitate the non-invasive assessment of lymph node status preoperatively, we use ultrasound to detect lymph node metastasis. We designed this study to obtain in vivo and vitro ultrasound features and parameters. Before surgery, the detailed ultrasound features are collected during routine ultrasound examination. After the completion of the axillary surgery, fresh lymph node specimens are collected for in vitro ultrasound evaluation one by one in a specially-designed detection system. Statistical models are built to categorize the probability of metastasis of lymph node according to a proposed categorization system similar as BI-RADS(Breast Imaging Reporting and Data System), which is named NI-RADS (Node Imaging Reporting and Data System).
