Assessment of liver injury using indocyanine green fluorescence imaging

BACKGROUND: To investigate whether indocyanine green (ICG) fluorescence imaging can be used to evaluate chronic and acute liver injury induced by either a high-fat (HF) diet or carbon tetrachloride (CCl(4)). METHODS: Sprague-Dawley (SD) rats were randomly divided into three groups: control group, HF diet-induced model group, and CCl(4)-induced model group. The chronic and acute liver injury models were induced by a HF diet and intraperitoneal injection of CCl(4), respectively. After HF feeding, the liver index, levels of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) of the rats were determined. The livers were also collected to evaluate histopathology damage by hematoxylin and eosin (H&E) staining. After in vitro perfusion of the liver and ICG administration, the liver fluorescence intensity and corresponding spectral value were measured by using real-image guided system (REAL-IGS). RESULTS: After HF feeding, the liver index and levels of serum ALT and AST were significantly increased, and the livers of the rats showed severe histopathological changes. Compared with the control group, the hepatic lobes of the model rats exhibited incomplete green fluorescence, and the corresponding spectral value was markedly reduced. CONCLUSIONS: ICG fluorescence imaging can be used to evaluate liver injury induced by either a HF diet or CCl(4).