Quantitative 3D Imaging of Mouse and Human Intrahepatic Bile Ducts in Homeostasis and Liver Injury.

Intrahepatic bile ducts (IHBDs) form a complex hierarchical network essential for liver function. The remodeling and expansion of this network during ductular reaction (DR) are hallmarks of liver disease that can be key indicators of disease severity. Conventional histology fails to capture the full extent of IHBD structural changes after injury due to the complex three-dimensional (3D) organization of the IHBD network that limits understanding of DR, especially in human tissue. A major barrier to leveraging 3D imaging as a diagnostic tool is the absence of standardized pipelines for IHBD imaging and analysis. This work establishes a robust 3D IHBD imaging and analysis workflow, applying it to both mouse and human liver tissues. This pipeline enables quantification of tissue and individual duct ("segment") level features and identifies features of invasive and noninvasive DR. In mouse models, we uncover regional phenotypes, including IHBD diverticula-like structures after duct blockage and the formation of anastomosed clusters after hepatocellular injury. Finally, this 3D imaging and analysis workflow is applied to quantify IHBD networks in human liver tissue. This work deepens our understanding of IHBD architecture in homeostasis and injury, laying the groundwork for advanced phenotyping of IHBD morphologies in mice and humans with relevance to next-generation experimental and diagnostic approaches to liver disease.