Figures & data
Figure 1. Optical-resolution photoacoustic microscopy (OR-PAM) for in vivo imaging of oxygenation and vascularization in the bone marrow. (A) Schematic diagram of the OR-PAM imaging system. AL, acoustic lens; CL, correction lens; DAQ, data acquisition; DM, dichroic mirror; FC, fiber coupler; M, mirror; ND, neutral density filter; PD, photodiode; PH, pinhole; PR, prism; SMF, single-mode fiber; SO, silicone oil; UT, ultrasonic transducer. (B) Imaging regions in the mouse skull.
Figure 2. The sO2 level and blood vessel density are inversely correlated with the tumor burden. (A) Images of sO2 levels acquired by OR-PAM and the corresponding fluorescence microscopy images. The mouse brain was imaged at Day 1, Day 14, and Day 28 after intravenous injection of MM cells. Scale bars: 1 mm. (B) Designated regions of interest (ROI) of mouse 1 and mouse 2 used for analysis denoted as normal areas, regions A and B, and tumor areas, regions C and D. (C) Tumor progression evaluated as the tumor area (mm2) measured at Days 1, 14, and 28 post MM cell injection (mean ± SD), n = 4. (Di) Comparison of average relative total sO2 level between tumor and normal regions over the course of 4 weeks and normalized to Day 1 post MM injection (mean ± SD), n = 4. (Dii) Correlation between the oxygenation (total sO2) and the tumor area (mm2) with correlation coefficient R2 = 0.8096. (Ei) Comparison of average blood vessel density between tumor and normal regions over the course of 4 weeks and normalized to Day 1 post MM injection (mean ± SD), n = 4. (Eii) Correlation between the blood vessel density and the tumor area (mm2) shows a correlation coefficient R2 = 0.7757.
