Application of Microvascular Flow (MV-Flow) Ultrasound in the Differential Diagnosis of Benign and Malignant Lymph Nodes.

OBJECTIVE

To investigate the value of Microvascular Flow (MV-Flow) vascular pattern and quantitative parameter vascular index (VI) in differentiating benign from malignant lymph nodes.

METHODS

A total of ninety-five patients who underwent ultrasound-guided lymph node aspiration biopsy at the First Hospital of Sun Yat-sen University between February 2023 and September 2023 were prospectively enrolled. Conventional ultrasound and MV-Flow examinations were performed, and the diagnostic efficacy was analyzed. The influencing factors of the VI were investigated.

RESULTS

Among grayscale features, lymph node hilum, shape, liquefaction, and calcification differed significantly between benign and malignant nodes (p < 0.05). In the vascular pattern of Color Doppler Flow Imaging (CDFI) and MV-Flow, benign nodes mainly showed hilar flow, while malignant nodes mainly showed mixed flow (p < 0.05 for both). MV-Flow and CDFI demonstrated comparable overall diagnostic performance (AUC: 0.682 vs. 0.646), with no statistically significant difference (p > 0.05). MV-Flow vascular pattern classification showed good interobserver agreement (κ = 0.801), and the vascular index (VI) demonstrated high reliability (ICC = 0.811). A moderate negative correlation was observed between lymph node depth and VI across all four sections.

CONCLUSIONS

MV-Flow provided superior qualitative visualization of microvascular flow compared to CDFI, but this did not translate into a statistically significant improvement in quantitative diagnostic performance for differentiating benign from malignant lymph nodes. Therefore, it should serve as a secondary diagnostic adjunct for lymph nodes with indeterminate CDFI findings, particularly to microvascular architecture that traditional Doppler fails to detect.