The contrast agent, ferumoxtran-10, is made of ultra small iron oxide particles (USPIO). Once they are injected through vein, they are taken up mostly by liver, spleen, bone marrow, and lymph nodes. It takes about 24 - 36 hours to reach peak uptake in the lymph nodes. The ability of current imaging techniques to detect the lymph nodes disease is known to be less than perfect. Current techniques only use anatomic information (size). Previous studies have shown that this new contrast agent may be able to detect normal and abnormal lymph nodes, using MRI procedure, called MRI lymphangiogram. This new contrast agent is being evaluated to determine whether it can be used to detect normal and abnormal lymph nodes.