Iron Oxide Nanoparticle MR Lymphangiography (ION-MRL): A quantitative technique for assessing the peripheral and central lymphatic systems.

A lack of clinical quantitative lymphatic metrics slows progress for innovation in treatment of lymphatic disease. MR lymphangiography provides high resolution anatomic analysis of the lymphatic system necessary for guiding new and emerging therapeutics but has not been explored as a quantitative metric. We coupled MR lymphangiography with iron oxide nanoparticles as the contrast agent and demonstrate the time to visualization of the thoracic duct is decreased in patients with bilateral lymphedema. Additionally, the change in R2* of inguinal lymph nodes after transpedal contrast injection quantifies lymphatic transit in patients with lymphedema.