High-resolution MR lymphangiography to evaluate lymphatic function in experimental rabbit limb lymphedema

Abstract

Objective To evaluate the feasibility of high-resolution MR lymphangiography with intracutaneous injection of gadodiamide, a commercially available, nonionic, extracellular paramagnetic con-trast agent,for the visualization of lymphatic vessels in lymphedema.Methods Post-surgical lymphedema was experimentally created in one hide limb of 6 rabbits.Another hide leg of each rabbit was used as the normal control.Four weeks later, normal and lymphedematous rabbit limbs were imaged following direct subcutaneous administration of gadobenate dimeglumine injection, 0.6 ml/limb.Images were obtained on axial and coronal planes with a Tl-weighted spin echo inversion-recovery sequence.Three days after above MR lymphangiography examination, LAS examination was applied as control.Results In the normal limb,collecting lymphatics and lymph node were clearly visualized as the Gd tracer was cleared from the intersti-tial compartnent rapidly.In contrast,the Gd tracer accumulated at the prior surgical site in the lymphed-ematous limb slowly.Quantitative assessment of Gd clearance demonstrated that accumulation of Gd was correlated with the impedance to lymph flow proximal to the site of surgical lymphatic ablation.Conclusion MR lymphangiography is a feasible and reliable method to be applied to quantitative functional imaging of the lymphatic vasculature in experimental models of lymphedema. Key words: Lymphedema ; Magnetic resonance ; Lymphangiography ; Function ;