Fig. 4.

Evaluation of Hypoxisense680 (HS680) uptake within the breast tumor via Multispectral optoacoustic tomographic imaging. Tail-vein catheters were inserted within female mice implanted with breast tumors. Mice were allowed to equilibrate within the device for 5 min with accumulation of baseline images each 10 s prior to HS680 injection. As time progressed, HS680 accumulated within the tumor microenvironment (t = 10, 15, 20, 25 min) as demonstrated in the rainbow color bar. Oxygenated hemoglobin (HbO₂) is shown in the corresponding images in red color scale. Combined HS680 and HbO₂ images demonstrate relative location of both contrasts, which was overlaid onto a single channel 900 nm wavelength background image.