Dynamic Evaluation of Vascular Remodeling and Aneurysm Progression Using Blood-Pool Contrast-Enhanced In Vivo Micro-CT in a Rodent Model.

Vascular graft remodeling and aneurysm progression are commonly studied in small animal models, but non-terminal methods for their assessment remain limited. This study evaluated contrast-enhanced micro-CT as a tool for longitudinal, in vivo monitoring of vascular grafts in rodents. Using a transplant model in which a pulmonary artery segment was implanted into the recipient's abdominal aorta, creating a pulmonary vascular graft, we compared a molecular iodinated contrast agent with a nanoparticle-based agent. The molecular agent was rapidly cleared, resulting in insufficient vascular opacification for graft visualization or quantification. In contrast, the nanoparticle agent provided prolonged vascular enhancement, enabling high-resolution imaging and quantitative assessment of graft morphology and aneurysm development over time. These findings demonstrate that contrast-enhanced micro-CT, particularly using nanoparticulate blood-pool contrast agents, enables a longitudinal, non-terminal evaluation of vascular grafts in rodents, enabling quantitative monitoring of graft remodeling, overcoming the limitations of traditional post-mortem, single timepoint analyses.