Objective To explore the diagnostic value of multimodal ultrasound imaging in axillary sentinel lymph node (SLN) metastasis of breast cancer.

Methods 52 patients with breast cancer confirmed by pathology in Qingdao Municipal Hospital from March 2020 to July 2021 were selected. The SLN localization was performed by contrast-enhanced ultrasound (CEUS), and routine ultrasound and real-time elastography (RTE) were performed. The efficacy of combined conventional ultrasound, CEUS and RTE multimodal ultrasound in the diagnosis of SLN was analyzed based on methylene blue staining and pathological results.

Results There were 68 SLN in 52 patients with breast cancer. The detection rates of SLN by methylene blue staining and percutaneous CEUS were 97.1% and 98.5%, respectively, with no significant difference. There were statistically significant differences between metastatic and non-metastatic SLN in terms of long-diameter/short-diameter ratio≤2, maximum thickness of cortex 3.0 mm, morphology, internal echo, normal lymph nodes, blood flow type, CEUS enhancement mode and RTE score (P < 0.05). The sensitivity of conventional ultrasound, CEUS, RTE and combined diagnosis for the diagnosis of SLN metastasis in breast cancer was 61.3%, 71.0%, 67.7% and 83.9% respectively, the specificity was 81.1%, 75.7%, 70.2% and 81.1% respectively, and the accuracy was 72.1%, 73.5%, 69.1% and 82.4% respectively. The sensitivity, specificity and accuracy of multimodal ultrasound combined diagnosis were higher than that of single examination. ROC curve indicated the area under the curve of conventional ultrasound, CEUS, RTE and their combined diagnosis were 0.712, 0.761, 0.737 and 0.825, respectively.

Conclusions Transcutaneous CEUS can accurately locate the SLN before operation, and it has good diagnostic efficacy in differentiating axillary SLN metastasis from breast cancer combined with conventional ultrasound and RTE, providing more imaging evidence for the diagnosis of SLN metastasis.