Combination of spectral and fluorescence imaging microscopy for wide-field in vivo analysis of microvessel blood supply and oxygenation.

Hyperspectral imaging of hemoglobin (Hb) saturation and first-pass fluorescence imaging of blood transit time were combined to analyze the oxygenation of and blood flow through microvessel networks. The combination imaging technique was demonstrated in a mouse dorsal window chamber model of a growing Caki-2 human renal cell carcinoma over time. Data from Hb saturation and blood supply time maps show the formation of arteriovenous malformations and shunting of blood directly from arteries to the tumor core and into veins in the periphery of the tumor. Images and data analysis show these malformations result in an oxygenated environment ideal for a tumor to proliferate.