[An experimental study on MR lymphography with various iron colloid agents]

Magnetic resonance (MR) lymphography with iron colloid agents was evaluated in an animal model. The agents examined were ferric gluconate (FeG), saccharated ferric oxide (SFO), iron chondroitin sulfate (ICS) and cideferron (CiF), which were used as intravenous medication for iron deficiency anemia. The author performed time-dose-response and correlative histologic studies. MR images of the popliteal lymph nodes of rabbits were obtained at 1.5 T with a spin-echo sequence (TR = 300, TE = 30 msec) before and after subcutaneous injection of the agents to dorsal hind-feet. The images were evaluated by signal intensity (SI). Histologic specimens were evaluated for distribution and relative quantity of stained iron with a color image analyzer. The SI with FeG 4 mgFe increased by 50% at 5 to 60 minutes after injection but returned to the pre-contrast level 48 hours after. The SIs with SFO 8 mgFe, ICS 1 mgFe and CiF 1 mgFe decreased to the background level at 60 minutes and 48 hours after. The histologic study in combination with the images indicated that in case of FeG the particles in lymph increased SI while in the other agents those within macrophages decreased SI.