To confirm NIR fluorophore kinetics in a large animal modelsystem approaching the size of humans, 35 kg Yorkshire pigswere injected intravenously with 2 mmol of NIR fluorophores andthe signal intensities of the AGs and the surrounding tissues andorgans measured over time. As shown in Fig. 3A, MB was notable to generate an SBR 4 1.0 at any time point. ICG generated ameasurable SBR relative to muscles, but not relative to thekidneys or liver. Both ESNF20 and ESNF31, however, resultedin a significant SBR relative to all nearby tissues and for anextended period of time. In fact, ESNF31 generated an SBR Z 3.0for 4 h post-injection. No changes in vital signs were observedover the 4 h experiment.