MRI of magnetically labeled mesenchymal stem cells in hepatic failure model

Figure 1 T2*-weighted gradient-echo magnetic resonance images show signal intensity changes of the liver after injecting superparamagnetic iron oxide-labeled human mesenchymal stem cells immediately before (A), 2 h (B) and 1 d (C), 7 d (D) after injection. Changes in signal intensity in the liver normalized to that of back muscle at 2 h, 1 d, and 7 d were 41.87% ± 9.63%, 10.42% ± 4.3%, and 3.75% ± 1.2%, respectively (P < 0.001). Note a significant signal drop of the liver at 2 h after injecting superparamagnetic iron oxide-labeled mesenchymal stem cells and gradual return of signal intensity compared with signal intensity before transplantation.

Figure 2 Photomicrographs of rabbit liver obtained after superparamagnetic iron oxide-labeled human mesenchymal stem cells injection via the mesenteric vein. A: Section obtained on day 1 shows distributions of Prussian blue stain-positive mesenchymal stem cells (MSCs) (arrows) in the liver parenchyma along the sinusoids; B: Section obtained on day 7 shows the localization of superparamagnetic iron oxide-labeled MSCs (arrows) in the border zone between normal liver parenchyma and hepatic injury areas.