Magnetic Resonance Lymphangiography for the Study of Lymphatic System in Lymphedema.

BACKGROUND Imaging of the lymphatic system is difficult because of its structural and anatomical characteristics, and the conventional diagnostic method, radionuclide-based imaging, has the disadvantage of poor resolution. Magnetic resonance (MR) imaging has been shown the capability of depicting lymphatic channels in lymphedema recently. The purpose of this study was to evaluate the imaging of MR lymphangiography (MRL) in diagnosis of limb lymphedema and its possible role in the microsurgical management of lymphedema. METHODS A total of 710 patients with primary lymphedema (n = 378), secondary lymphedema (n = 332), were enrolled in the study. Contrast-enhanced lymphangiography was performed with 3.0 T MR unit (Philips Medical Systems, Best, The Netherlands) after intracutaneously injection of gadobenate dimeglumine. Kinetic of enhanced lymph flow within lymphatics and lymph nodes as well as the morphological abnormalities of lymphatic system were evaluated. RESULTS MRL was able to display the detailed anatomical changes in the vessels and nodes. In primary lymphedema, there are three major types of lymphatic system malformation: (1) only lymph nodes affected, (2) only lymph vessels affected, and (3) both lymph vessels and lymph nodes affected. In secondary lymphedema MRL clearly demonstrated tortuous and dilated collecting lymphatics in lymphedemtous limbs. MRL also provided information concerning the functional status of lymph transport in lymphatic vessels and nodes by real-time visualization of enhanced lymph flow in lymphatic channels and within lymph nodes. CONCLUSION Contrast MRL was capable of evaluating the anatomical and functional status of lymphatic vessels and lymph nodes in lymphedematous limb. This new imaging shows good potential for use in the diagnosis and surgical management of lymphedema.