Differentiating benign and malignant superficial lymph nodes using super-resolution contrast enhanced ultrasound - a pilot study.

OBJECTIVE

The study aimed to evaluate the feasibility and clinical value of super-resolution contrast enhanced ultrasound (SR CEUS) in the differential diagnosis of superficial lymph nodes (LNs) and to establish an appropriate imaging protocol.

METHOD

Patients with enlarged superficial LNs from March to August 2024 were prospectively enrolled. SR CEUS were performed post bolus injection of 0.5 ml and 1.0 ml microbubble contrast agents for 6 s. Microvascular density (MVD), flow weighted density of the vessel (FWVD), perfusion index (PI), fractal dimension (FD), velocity variance (Vel var) and mean velocity (Vmean) were generated from SR CEUS images. The parameters were statistically analyzed to differentiate benign from malignant LNs. The dosage of contrast agent and the duration of image acquisition suitable for diagnosis were explored.

RESULTS

34 malignant and 20 benign LNs were included. Post 0.5 ml injection, the benign LNs showed significantly higher MVD, FWVD, PI and lower Vel var compared with malignant LNs from the 1st to 6th second, and the gap of parameters between benign and malignant LNs increased over time; Post 1.0 ml injection, no significant difference existed between benign and malignant LNs in terms of all parameters.

CONCLUSIONS

This study demonstrated the feasibility of using SR CEUS for the differential diagnosis of superficial LNs, with 0.5 ml bolus injection of contrast agent and 6 s acquisition time recommended for clinical practice. Parameters MVD, FWVD, PI & Vel var could serve as imaging markers for clinical evaluation of superficial LNs.

CLINICAL TRIAL NUMBER

Not applicable.