The role of contrast enhanced ultrasound in the assessment of superficial lymph nodes.

Evaluation of superficial lymphadenopathy is important for patients with pathologies like head and neck cancers or breast cancer, as it helps the assessment of patient prognosis and the selection of treatment method. Cervical lymph nodes are also common sites of involvement in lymphoma. Lymphomatous nodes are usually difficult to differentiate from metastatic nodes in clinical examinations. As the treatment for lymphoma and metastases is different, accurate differential diagnosis between the two conditions is important. Ultrasound is a useful imaging modality in evaluation of superficial lymphadenopathy because of its high sensitivity and specificity, especially when combined histopathology. With the use of power Doppler sonography, the vasculature of the lymph nodes can also be evaluated, which provides additional information in the sonographic examination of superficial lymph nodes. But there are still nodes that cannot be examined by Doppler or their vasculature cannot be visualized. So, in the last decade, contrast-enhanced ultrasound was more and more discussed as a non-invasive method for a more accurate differential diagnosis of cervical lymphadenopathy.