The aim of our study was to assess if hepatic fibrogenesis and fibrolysis could by differentiated with USPIO-enhanced MR imaging in mice, based on differential uptake of fluorescent USPIO by macrophages. The change in R2* were significantly higher in the fibrogenesis group compared to the healthy group and the regression group 24 hours after the injection of USPIO. Higher USPIO uptake was observed with fluorescence microscopy during fibrogenesis relative to uptake in fibrolysis and healthy livers. Significant correlation was found between R2* and fluorescence intensity. These results suggest that the dynamics of fibrogenesis can be assessed with USPIO enhanced MR imaging.