High-resolution micro-CT imaging protocols for studies of intracranial aneurysms in murine models

Unruptured Intracranial Aneurysms (UIAs) pose significant clinical challenges due to their risk of growth and rupture. Early and accurate imaging is essential for effective management and understanding their pathophysiology. This study integrates three advanced imaging modalities—Photon Counting Computed Tomography (PCCT), dynamic perfusion micro-CT, and high-resolution ex vivo vascular micro-CT with MICROFIL—to enhance UIA research using a well-established mouse model. UIAs were induced in 3–5-month-old C57BL/6J mice through angiotensin II infusion and elastase injection. In vivo PCCT imaging with a blood pool contrast agent successfully delineated the Circle of Willis, revealing vascular asymmetries in a fusiform aneurism and increased vessel diameters (~15%), indicative of aneurysmal changes. Dynamic perfusion micro-CT captured temporal blood flow dynamics within the Circle of Willis, producing perfusion maps such as Time-to-Peak and Mean Transit Time, though noise reduction and improved resolution are necessary. High-resolution ex vivo imaging at 22 μm provided detailed 3D visualizations of the vasculature, but challenges such as vessel rupture and contrast accumulation highlight the need for protocol optimization. This is the first study to demonstrate a comprehensive imaging pipeline for UIAs in preclinical models, combining anatomical, functional, and ultra-high-resolution imaging. These findings lay the groundwork for future advancements in imaging protocols and computational techniques, facilitating deeper insights into aneurysm progression and informing the development of targeted therapies.