Fig. 1. Schematic of photoacoustic imaging of acute respiratory infection based on Nano-ICG

Fig. 2. Characterization of Nano-ICG.（a）Transmission electron microscopy（TEM）plots of Nano-ICG particles；（b）UV absorption spectra of Nano-ICG between 600 and 850 nm；（c）cytotoxicity testing of Nano-ICG

Fig. 3. Confocal imaging results of Nano-ICG phagoidities of macrophages at different moments

Fig. 4. PAI and analysis results of Control group and Model group. (a) Integrated images of PAI and US images of mouse airways before and after Nano-ICG injection in Control and Model groups; (b) number of Nano-ICG in airway of mice in Control group versus injection time; (c) number of Nano-ICG in airway of mice in Model group versus injection time

Fig. 5. PAI results of mouse airway. (a) Three denominational PAI images of mouse airway on second day after LPS instillation; (b) fluorescent image of inflamed airway labeled by Nano-ICG

Fig. 6. Comparison of staining results of respiratory tract sections between control group and model group. (a) Control group; (b) Model group