Figure 1.

In vivo lifetime characteristics of commercially available NIR fluorophores. Mice were administered NIR fluorophores and imaged for up to 1 day to determine biodistribution and in vivo fluorescence lifetimes. Planar fluorescence images were thresholded and each pixel was fit for a monoexponential decay. Monoexponential lifetime maps for (a) Osteosense and (b) Kodak X-Sight 761, overlaid on a white light planar reflectance image of the mouse. (c) Histogram of pixel lifetime values from (a) and (b). The two fluorophores have distinct, separable lifetimes in vivo.