Comparison study of radionuclide lymphoscintigraphy and dynamic magnetic resonance lymphangiography for the diagnosis of extremity lymphedema

Objective To compare the role of radionuclide lymphoscintigraphy and dynamic magnetic resonance lymphangiography ( MRL) for the diagnosis of extremity lymphedema. Methods Sixteen patients with primary extremity lymphedema and two with Klippel-Trenaunay syndrome combined with lymphedema were examined by lymphoscintigraphy using the tracer 99Tc-labelled dextran, and also by MRL using gadobenate dimeglumine as contrast agent. The results of morphological abnormalities and functional state of the lymphatic system at affected limbs from the two imaging methods were compared. Results Lymphatic vessels were imaged in 14 of 18 limbs with lymphedema using MRL, compared with one of 18 using lymphscintigraphy. MRL detected the inguinal nodes in 16 of 17 patients, whereas lymphscintigraphy revealed inguinal nodes in only nine cases. 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. Conclusions Dynamic MRL is more sensitive and accurate than lymphoscintigraphy in the detection of anatomical and functional abnormalities in the lymphatic system in patients with extremity lymphedema. Key words: Lymphedema;  Lymphography;  Radioisotopes;  Magnetic resonance imaging