Lymphoscintigraphy is a special type of nuclear medicine imaging that provides pictures called scintigrams of the lymphatic system. The lymphatics are a complex network of small vessels, similar in many ways to blood vessels, only instead of being transporting conduits for blood they transport a clear fluid called lymph. This scan is often performed to identify blockages of the lymphatic system in the arms or legs, also known as lymphoedema.

Very small amounts of radiopharmaceuticals are injected into the skin within the first web spaces of the hands or feet. The radiopharmaceutical contains a low dose of a radioactive isotope, which emits gamma rays. These gamma rays are detected by a special camera, called a gamma camera, and a picture of the lymphatic drainage in the arms or legs is created.

The lymphoscintigram can help doctors confirm the presence of lymphoedema.