Evaluation of metastases and reactive lymph nodes in Doppler sonography using an ultrasound contrast enhancer

The authors conducted a prospective study in D-galactose signal-enhanced Doppler sonography of lymph nodes to investigate new aspects in differentiating malignant from reactive lymph nodes of patients with suspected malignancy of the neck.

Twenty-one patients with suspected squamous epithelial cell carcinoma metastases of the neck were examined by Doppler sonography before and after administration of an ultrasound signal-enhancing agent, consisting of D-galactose microbubbles. Qualitative sonomorphology, peak flow rates, and pulsatility and resistive indices were assessed.

Compared with conventional Doppler, enhanced Doppler sonography gave detailed additional information about vascularization of metastases or reactive lymph nodes. Signal-enhanced Doppler of metastases showed a relatively characteristic pattern of vascularity, therefore facilitating differential diagnoses and allowing better discrimination from surrounding tissue, demonstrated by the infiltration of neighboring vessels in the neck. Concerning reactive lymph nodes, vascularization could be stated and measured in many cases only after signal enhancement. Evaluating peak velocities and pulsatility and resistive indices could not differentiate significantly malignant from reactive lymph nodes.

Administration of a D-galactose-based signal-enhancer helps to differentiate malignant from reactive lymph nodes of the neck. It is superior to conventional Doppler by improving evaluation of the vascularity and could be of use for staging procedures.