A novel imaging tool for hepatic portal system using phase contrast technique with hydrogen peroxide-generated O₂ gas

The objective of this study was to investigate the potential of hydrogen peroxide-generated oxygen gas-based phase contrast imaging (PCI) for visualizing mouse hepatic portal veins. The O₂ gas was made from the reaction between H₂O₂ and catalase. The gas production was imaged by PCI in real time. The H₂O₂ was injected into the enteric cavity of the lower sigmoid colon to produce O₂ in the submucosal venous plexus. The generated O₂ gas could be finally drained into hepatic portal veins. Absorption contrast imaging (ACI) and PCI of O₂-filled portal veins were performed and compared. PCI offers high resolution and real-time visualization of the O₂ gas production. Compared with O₂-based ACI, O₂-based PCI significantly enhanced the revealing of the portal vein in vivo. It is concluded that O₂-based PCI is a novel and promising imaging modality for future studies of portal venous disorders in mice models.