A new method of lymphatic channel
mapping was evaluated in a retrospective review of pre-surgical lymphedema MR
exams. Dual Agent Relaxation Contrast MR Lymphangiography (DARC-MRL) uses
intracutaneous injection of a Gd contrast agent for enhancement of lymphatic
channels and concomitant intravenous injection of USPIO (ferumoxytol) for
suppression of (otherwise lymphatic-obscuring) veins. 43 MR exams using
DARC-MRL were compared to 43 matched exams using conventional (no USPIO) MR
lymphangiography. Exams were graded for degree of venous contamination, and
DARC-MRL exams exhibited dramatically less obscuring venous contamination than
the conventional method.