SUper-Resolution Ultrasound Imaging of Erythrocytes (SURE) in Normal and Malignant Lymph Nodes

The goal of this observational study is to visualize the small vessels in normal and cancerous lymph nodes on the neck with a new ultrasound technique. The main questions it aims to answer are: * Is it possible to visualize the network of the smallest vessels in lymph nodes on the neck? * Is it possible to distinguish between healthy and cancerous lymph nodes using different parameters? The participants will have 1 lymph nodes ultrasound scanned with a standard ultrasound technique and the new technique.