In vivo Hyperpolarized Metabolic Imaging to Monitor the Progression of Hepatitis B Virus (HBV)-Related Hepatitis to Liver Fibrosis.

Purpose: This study aimed to assess metabolic changes to monitor the progression from normal liver to hepatitis B virus (HBV)-related hepatitis and liver fibrosis using hyperpolarized ¹³ C magnetic resonance imaging (MRI).
Procedures: Hepatitis was induced in mice (n = 16) via hydrodynamic injection of HBV 1.2 plasmid (25 μg). Among them, liver fibrosis was induced in the mice (n = 8) through weight-adapted administration of thioacetamide with ethanol. Normal control mice (n = 8) were injected with a phosphate buffer solution. Subsequently, a hyperpolarized ¹³ C MRI was performed on the mouse liver in vivo. The level of hepatitis B surface antigen (HBsAg) in blood serum was measured. Statistical analysis involved comparing the differential metabolite ratios, blood biochemistry values, and body weight among the three groups using the Kruskal-Wallis one-way analysis of variance.
Results: HBsAg was absent in the normal and fibrosis groups, while it was detected in the hepatitis group. The ratios of [1- ¹³ C] lactate/pyruvate, [1- ¹³ C] alanine/pyruvate, [1- ¹³ C] lactate/total carbon, and [1- ¹³ C] alanine/total carbon were significantly lower in the normal control group than in the hepatitis and fibrosis groups (p < 0.05). Moreover, these ratios were significantly higher in the fibrosis group than in the hepatitis group (p < 0.05). However, no significant differences were observed in either [1- ¹³ C] pyruvate-hydrate/pyruvate or [1- ¹³ C] pyruvate-hydrate/total carbon among the three groups.
Conclusions: The levels of [1- ¹³ C] lactate and [1- ¹³ C] alanine in vivo may serve as valuable indicators for differentiating between HBV-related hepatitis, liver fibrosis, and normal liver.
(© 2024. The Author(s), under exclusive licence to World Molecular Imaging Society.)