Liver metastases: safety and efficacy of detection with superparamagnetic iron oxide in MR imaging.

PURPOSE

To evaluate the clinical and biologic safety of superparamagnetic iron oxide (SPIO) as a contrast agent in magnetic resonance (MR) imaging and to assess its efficacy in the detection of liver metastases.

MATERIALS AND METHODS

Twenty adults with liver metastases underwent MR imaging at 1.5 T before and 1 hour after infusion of SPIO. Four spin-echo (SE) sequences and one gradient-echo (GRE) sequence were used.

RESULTS

There were no adverse reactions. Alterations in serum protein, serum iron, transferrin, and ferritin levels and transferrin saturation coefficient were statistically significant. The mean tumor-to-liver contrast-to-noise ratio (C/N) increased markedly with all sequences. The best postcontrast tumor-to-liver contrast was obtained with the GRE sequence (repetition time msec/echo time msec = 300/15). The mean number of apparent lesions detected after administration of SPIO increased by 12 with the proton-density-weighted SE sequences (800/30 and 2,500/30), four with the T2-weighted SE sequence (2,500/90), and seven with the GRE sequence (300/15).

CONCLUSION

SPIO is safe, increases tumor-to-liver C/Ns with some sequences, and improves the detection of liver metastases.