Upper: Infrared images (image resolution: 84 μm; focus offset: 1 mm) revealing the lungs, kidney, spleen, and liver of rats 2 weeks after the intravenous infusion of 4 × 106 MSCs (experimental rats 1–3) or vehicle (Control). Although some cells remain in the pulmonary tissue, there are significantly fewer than those seen 48 hours postinfusion. Lower: Bar graph showing lung integrated intensities of the experimental animals, which were not significantly different from those from controls (p = 0.10, t-test).