Background: Visualization of the lymphatic vessels is a challenge in patients with disorders of the lymphatic circulation. In an effort to improve the diagnostic scope of lymphatic imaging, we compared traditional lymphoscintigraphy (LSG) with three-dimensional magnetic resonance imaging (3D MRI). Methods: From October 1, 2002, to May 30, 2004, 39 patients (27 males and 12 females) with lower extremity lymphedema and/or skin lymphorrhea in the abdominal wall or the external genitalia underwent LSG and 3D MRI. Patients' ages ranged from 3 to 71 years. Assessment of the imaging studies included the degree and quality of visualization of the malformations of the lymphatic collectors, lymphatic trunks, lymph nodes, and tissue edema. Results. In patients with lymphedema, chylous reflux syndrome, or both, LSG depicted the enlarged lymphatics and nodes as a fused band or mass. In 3D MRI, the dilated superficial lymphatic collectors and deep lymphatic trunks, as well as the accumulation of chyle and node enlargements, were clearly visualized. In patients with hypoplasia or aplasia of the lymphatics, LSG usually displayed the pattern of dermal backflow in the form of radiotracer filling of the dermal lymphatics or stagnation of the isotope at the injection point. The images obtained by 3D MRI were able to demonstrate the extent of tissue fluid accumulation and distinguish edema fluid from subcutaneous fat. Conclusions. In patients with peripheral and central lymphatic malformations, LSG provided images representative of the function of the lymphatic vessels but failed to give detailed information regarding its anatomy. 3D MRI provided extensive information on the anatomy of the lymph stagnated vasculature as well as on the effects of lymphatic dysfunction on local structures and tissue composition.
