ICG lymphography is a study of the superficial lymphatics, not a treatment, helps define lymphatic dysfunction and delineate individualized lymphedema treatment. This study also helps visualize lymphedema in the asymptomatic limb. Superficial lymphatics accounts for 70% of the lymphatic system.

Indocyanine green (ICG) is a contrast that fluoresces in the near infrared range and therefore needs a special camera to be seen after injection. Low dose ICG injected into the subcutaneous tissue has been used to map lymphatics; this is known as ICG lymphography. The ICG binds to a protein called albumin, which is taken up into the lymphatics, and transported within the lymph fluid. In this way, the function of the lymphatics can be assessed.