Purpose: The aim of this study was to assess the feasibility of using intravenously administered gadofosveset trisodium as a negative contrast agent for lymph node (LN) assessment with diffusion-weighted imaging (DWI) using a VX2 tumor model in rabbits.
Materials and methods: VX2 cells were injected in the right hind limb of five Japanese white rabbits to induce ipsilateral popliteal LN metastasis. DWI was performed before and every 7.5 min (until 1 h) after intravenous gadofosveset trisodium administration, at 1.5 T. Signal intensities (SIs) of right (metastatic) and left (nonmetastatic) popliteal LNs at each time point were measured and compared to each other using two-sided unpaired t-tests.
Results: The SIs of metastatic lymph nodes were significantly higher (P < 0.05) than those of nonmetastatic LNs at each time point after intravenous gadofosveset trisodium administration. Although the SI of metastatic LNs was significantly higher (P = 0.0237) than that of nonmetastatic LNs before contrast injection, this difference became even more significant (P ≤ 0.0105) after gadofosveset trisodium administration.
Conclusion: The SI of metastatic LNs at DWI is less suppressed than that of nonmetastatic LNs after the intravenous administration of gadofosveset trisodium. Therefore, intravenously administered gadofosveset trisodium shows promise for use as a negative contrast agent for discriminating metastatic from nonmetastatic LNs at DWI.