Diagnosis of liver fibrosis and liver function reserve through non-invasive multispectral photoacoustic imaging

Liver function reserve (LFR) is the sum of remnant functional hepatic cells after liver injury. In the pathologic process of liver fibrosis (LF), LFR is impaired. LFR assessment can help determine the safe scope of liver resection or drug regimen and predict prognosis of patients with liver disease. Here, we used a photoacoustic imaging (PAI) system to assess LF and LFR in rabbit models. We performed PAI, ultrasound elastography and biopsy for 21 rabbits developing none (n = 6) and LF (n = 15). In vivo indocyanine green (ICG) measurements by PAI showed that LF group presented a significantly attenuated ICG clearance compared to control group, indicating LFR impairment of LF. Another finding was a significantly higher collagen photoacoustic signal intensity value was observed in LF both in vivo and in vitro. Our findings demonstrated that PAI was potentially effective to evaluate LFR and collagen accumulation of LF.