Fig. 1. Schematic of the project diagram. (a) Workflow of the cross-scale optical imaging evaluating the cholestatic diseases. (b) Verification of model establishment by H&E and immunohistochemical staining. UT, ultrasonic transducer; CL, conical lens; OC, optical condenser.

Fig. 2. Monitoring of hepatic lobular structure and function. (a) Structural image of the liver obtained by PAM at 532 nm. (b) Cross-sectional photoacoustic signal distribution along the white dotted line of the capillary, and its corresponding full width at half maximum calculated after Gaussian fitting. (c) Filtering and binarization of PAM images. (d) Skeletonized PAM images after feature extraction. (e) PAM mapping of sO₂ in cholestatic disease. Quantitative analysis of average vessel diameter (f), vessel area density (g), total vessel length (h), and sO₂ (i) in cholestatic disease. All comparisons were made against the control group.

Fig. 3. Assessment of the intrahepatic bile duct permeability. (a) Dynamic of EB penetration with time captured after EB retrograde injection. (b) Differential PA images obtained by subtracting the pre-injection image from each time point. Quantitative analysis of the enhanced photoacoustic signal intensity (c) and relative diffusion area (d) in (a).

Fig. 4. Clearance process of ICG at the organ level. (a) NIR-II fluorescence imaging at different time points following intravenous injection of ICG. (b)–(d) Time-dependent NIR-II fluorescence signal intensities in the liver of various groups. (e) Quantitative analysis of the NIR-II fluorescence signal intensities at 7 h post-injection in each group. All comparisons were made against the control group.

Fig. 5. Quantitative comparison of the ICG transport process at the microscopic level. Early transport process ICG in the control group (a) and PBC group (c). NIR-II fluorescence signal intensities of blood vessels (black arrow) and liver parenchyma (red arrow) indicated by the circle at different time points in the control group (b) and PBC group (d). (e) Deposition process of ICG over time in the cholestatic spot (blue arrow). (f) Quantitative analysis of the fluorescence signal area in the single cholestatic region (blue arrow) at different time points. (g) Comparison of cholestatic characteristics at 7 h post-injection in the BDL-1W and BDL-2W. Calculation of the single cholestatic area (h) and cholestatic density (i) in BDL-1W and BDL-2W, respectively.

Fig. 6. Evaluation of the liver function reserve by PACT. (a) PACT image of the liver after ICG injection. (b) Liver metabolic curves in different groups. (c) Quantitative data of kinetic parameters Tmax and T1/2.