LYMPHATIC IMAGING IN EXPERIMENTAL FILARIASIS USING MAGNETIC-RESONANCE

RATIONALE AND OBJECTIVES. To evaluate acquired lymphatic abnormalities caused by filariasis, the authors examined the peripheral lymphatic s ystem in normal ferrets and those chronically infected with Brugia mal ayi using magnetic resonance imaging (MRI). The findings were compared with previously obtained lymphangioscintigraphic (LAS) images in ferr ets both with and without experimental filariasis. METHODS. Fifteen fe rrets (11 infected with B. malayi and four noninfected controls) under went whole body coronal MRI using a quadrature transmission-receive he ad coil at 0.5 Tesla operating at a resonant frequency of 21.5 mHz for protons with a 25-cm field of view. RESULTS. In contrast to normal an imals, infected ferrets showed dilated hindlimb dermal lymphatic colla terals, enlarged high-signal intensity groin lymph nodes with punctate low-signal intensity centers and separate low-signal intensity spots with irregular thin channels, suggestive of nests of viable adult nema todes within tortuous lymphatics and nodes. MRI correlated with the LA S findings, and the interpretations were supported by light, scanning electron, and video microscopy. CONCLUSIONS. T2-weighted MRI in conjun ction with LAS accurately depicts the peripheral lymphatic system in f ilarial-infected ferrets. These two modalities are useful complementar y techniques to examine disorders characterized by lymphatic insuffici ency.