Liver tumors in cirrhosis: experimental study with SPIO-enhanced MR imaging

The influence of cirrhosis on superparamagnetic iron oxide (SPIO)-enhanced magnetic resonance (MR) imaging of the liver was studied in 31 rats. Experimental models included carbon tetrachloride-induced cirrhosis and liver engrafting of rhabdomyosarcoma S4T cells. Hepatic uptake of SPIO measured with relaxometry decreased dramatically with histologic grade, while splenic uptake increased; the same results were achieved by calculating K values. Imaging of 13 tumorous cirrhotic rats confirmed these results by showing a muted decrease in liver signal intensity on spin-echo images after injection of SPIO. Nevertheless, all intrahepatic tumors could be visualized, as confirmed by postmortem examination. On gradient-echo images, postinjection contrast between the tumor and the liver was not affected by cirrhosis. Thus, despite strong impairment of hepatic uptake in cirrhosis, the diagnostic efficacy of MR imaging with SPIO did not seem to be significantly affected.