Fig. 1. Schematic of photoacoustic microscopy imaging system

Fig. 2. Resolution test results of photoacoustic microscopy system. (a) Physical image of surgical blade; (b) photoacoustic image of surgical blade; (c) system lateral resolution function fitting diagram; (d) system axial resolution function fitting diagram with photoacoustic image of carbon fibers shown in inset

Fig. 3. Quantitative analysis of tumors by bioluminescence imaging method. (a) Schematic of bioluminescence imaging; (b) tumor localization

Fig. 4. Photoacoustic microscopic imaging and diameter analysis of normal liver micro-vascular structure. (a) Photoacoustic image of hepatic lobules of normal liver tissue; (b) central vein and hepatic sinuses; (c) quantitative analysis of diameter of hepatic blood sinuses

Fig. 5. Photoacoustic microscopic imaging of micro-vascular structure in HCC mice liver tumors. (a) Structure of hepatic lobules adjacent to carcinoma; (b) (c) structures of vessels adjacent to cancerous tissue; (d) central vessel of tumor

Fig. 6. Quantitative analysis of HCC microvascular diameter. (a) Diameter of hepatic lobular vein branches adjacent to carcinoma; (b) (c) diameters of vessels adjacent to cancerous tissue; (d) diameter of central vessel of tumor

Fig. 7. Analysis of vascular density and diameter in normal and cancerous tissues. (a) Vascular density; (b) frequency distribution of vessel diameter

Fig. 8. Oxygen saturation mapping in normal liver blood vessels and tumor micro-vessels. (a) Oxygen metabolism in normal liver vessels; (b) oxygen metabolism of hepatic lobules adjacent to carcinoma; (d) oxygen metabolism in normal hepatic lobular; (c)(e) oxygen metabolism in vessels adjacent to cancerous tissue; (f) oxygen metabolism in central vessels of tumor