In the article titled “Erbium-Based Perfusion Contrast Agent for Small-Animal Microvessel Imaging” [1], there were errors in the scale bars in Figure 3, which should be corrected as follows:


Figure 3 
Rebinned 100 μm voxel images where the (a) maximum intensity projection (MIP) of a whole body perfused mouse demonstrates that the attenuation of the Er2O3 contrast agent in the vasculature is higher than the mouse’s skeletal structure. Quantitative measurements of attenuation (in HU) were obtained from regions drawn within heart (b), testes (c), inferior vena cava (d), and cortical bone (e).