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Shetty. Plast Aesthet Res 2022;9:47 https://dx.doi.org/10.20517/2347-9264.2022.41 Page 7 of 9

Figure 4. Sample lower extremity MR lymphangiography exam in a 67-year-old man with long-standing unilateral right lower extremity
lymphedema. (A) Coronal T2-weighted single-shot fast-spin echo MRI shows unilateral right lower extremity lymphedema
characterized by both excess fat and water accumulation. (B) Coronal heavily T2-weighted fast spin-echo MRI highlights the
distribution of fluid accumulation with greater conspicuity. (C) Coronal T1-weighted Dixon water-only 3D spoiled gradient echo MRI
obtained 30 min after lymphatic contrast injection shows dilated lymphatics channels in the medial right ankle and thigh (arrows). (D)
Coronal T1-weighted Dixon water-only 3D spoiled gradient echo MRI venogram obtained 120 s after intravenous contrast
administration shows normal venous outflow in the right lower extremity. MRI: Magnetic resonance imaging.

Venous contamination after lymphatic injection is common and encountered on nearly every exam, likely
due to intracutaneous transit of gadolinium into the veins [9,15] . We overcome this with the use of a delayed
venogram to help differentiate superficial veins, which enhance more brightly after intravenous contrast
injection, from lymphatic channels [Figure 5]. This is performed as the final acquisition (approximately 40
min after lymphatic contrast injection) 120 s after administration of intravenous contrast to allow for
uniform venous enhancement. Some centers use a dual-agent relaxivity contrast (DARC) MRL technique in
which intravenous ferumoxytol contrast is administered and images obtained in such a way to null blood
vessel signal, limiting enhancement only to lymphatic structures [16,17] . However, the US Food and Drug
Administration (FDA) warns of potentially fatal allergic reactions to ferumoxytol and urges IV infusion
over 15 min and close monitoring for signs of allergic reactions, including blood pressure and pulse
monitoring, for at least 30 min following infusion, creating additional logistical challenges if used .
[18]
Finally, although direct cost-benefit analysis is not available locally nor previously evaluated in the
literature, MRL is an expensive proposition, both in terms of the time and energy invested in starting a
program and the actual cost of the exam to a patient. Before embarking on such a journey, factors such as
surgical expertise, a comprehensive care infrastructure including lymphatic therapy, and adequate demand
within the local population should be assessed to ensure sufficient need and volume as to support the new
program.