Comparison of radionuclide lymphoscintigraphy and dynamic magnetic resonance lymphangiography for investigating extremity lymphoedema

Background: Lymphoscintigraphy is widely used to image the lymphatic system. The aim of this study was to compare lymphoscintigraphy and dynamic magnetic resonance lymphangiography (MRL) in the investigation of extremity lymphoedema. Methods: Sixteen patients with primary extremity lymphoedema and two with Klippel-Trenaunay syndrome with lymphoedema were examined by lymphoscintigraphy using the tracer (99)Tc-labelled dextran, and by MRL using gadobenate dimeglumine as contrast agent. Morphological abnormalities and functional state of the lymphatic systems of affected limbs were compared between the two imaging methods. Results. Lymphatic vessels were imaged in 14 of 18 limbs with lymphoedema using MRL, compared with one of 18 using lymphoscintigraphy. MRL detected the inguinal nodes in 16 of 17 patients, whereas lymphoscintigraphy revealed inguinal nodes in only nine. MRL revealed more precise information about structural and functional abnormalities of lymph vessels and nodes than lymphoscintigraphy by real-time measurement of lymph flow in vessels and nodes. Conclusion: Dynamic MRL was more sensitive and accurate than lymphoscintigraphy in the detection of anatomical and functional abnormalities in the lymphatic system in patients with extremity lymphoedema.