Hepatic ischemia reperfusion injury (IRI) induces cellular damage and causes cell death. It can lead to acute liver failure accompanied with biochemical changes, microcirculatory disturbances and/or histopathologic changes. Early detection of impaired liver function is vital for effective therapeutic interventions and thus prevents its progression to liver failure. However, an in vivo study of hepatic IRI model in combination with hyperpolarized ¹³C magnetic resonance spectroscopy (¹³C MRS) and diffusion-weighted imaging (DWI) has not yet been attempted until now. The purpose of this study was to investigate the cellular metabolite change, diffusion of water molecules and microcirculation of blood in rat model with hepatic IRI and their correlations with enzyme levels.The hepatic IRI model in six male Sprague-Dawley rats was induced in the median and lateral hepatic lobes by clamping the portal triad (hepatic artery, portal vein and bile duct) for 1 hour. Then, the clamp was removed to initiate hepatic reperfusion for 1 hour. MRI was performed on a 3T GE MR750 scanner after reperfusion to obtain apparent diffusion coefficient (ADC) and perfusion fraction (f) maps using intravoxel incoherent motion DWI (IVIM-DWI). HyperSense DNP polarizer was used to hyperpolarize [1-¹³C] pyruvic acid and the real time ¹³C MRS and metabolic imaging were performed on the rat liver following an injection of hyperpolarized [1-¹³C] pyruvate.The levels of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) significantly increased in the IRI-induced rats compared to normal rats (Table 1). In the IRI-induced rat model, the ratios of [1-¹³C] alanine/pyruvate and [1-¹³C] lactate/pyruvate were significantly increased, and these findings were positively correlated with the increased enzyme levels of ALT and LDH (Fig. 1 and 2; Table 1). Also, the perfusion fraction values in IRI-induced rats were significantly lower than those of normal rats, whereas the ADC values were not significantly different between the two groups (Fig. 3). From these findings, we assume that significant increases of [1-¹³C] alanine and [1-¹³C] lactate are closely related enzymatic activity, and the levels of [1-¹³C] alanine and [1-¹³C] lactate in combination with perfusion fraction values are potentially considered as the noninvasive biomarker for assessing the hepatic ischemia reperfusion injury in a rat model.Our study demonstrated the cellular metabolite changes on hepatic IRI in rats by using a real time in vivo hyperpolarized ¹³C dynamic MRS and metabolic imaging in combination with enzyme levels and perfusion fraction values. The levels of [1-¹³C] alanine and [1-¹³C] lactate are potentially considered as important biomarkers for the diagnosis of hepatic IRI. These findings will be valuable for an understanding of the mechanisms of hepatic damage.