In Vivo Three-Dimensional Geometric Reconstruction of the Mouse Aortic Heart Valve.

Area of Science:

• Biomedical Engineering
• Cardiovascular Research
• Medical Imaging

Background:

• Aortic valve (AV) disease affects 5% of those aged 65+, with prevalence increasing with age.
• Current artificial heart valves have limited durability, and non-surgical treatments are lacking due to incomplete understanding of AV disease.
• Mouse models are valuable for studying AV disease genetics and testing treatments, but their small size and fast heart rates hinder organ-level studies.

Purpose of the Study:

• To develop a method for 3D reconstruction of the in vivo functional murine aortic valve (mAV) geometry.
• To enable longitudinal characterization of mAV disease in murine models.
• To overcome limitations of previous ex vivo and small-scale studies of mAV.

Main Methods:

• Extended a novel ex vivo micro-CT-based 3D reconstruction methodology.
• Utilized high-frequency four-dimensional ultrasound (4DUS) to capture in vivo mAV geometry.
• Digitized mAV mid-surface coordinates and developed a NURBS-based geometric model fitted to in vivo 4DUS and ex vivo micro-CT data.

Main Results:

• Successfully reconstructed the 3D in vivo mAV geometry in both closed and open states with high fidelity.
• This represents the first achievement of such in vivo 3D reconstruction for murine aortic valves.
• The method allows for robust assessment of in vivo mAV leaflet kinematics in 3D.

Conclusions:

• The developed 4DUS-based method enables high-fidelity 3D reconstruction of in vivo murine aortic valve geometry.
• This breakthrough facilitates longitudinal studies of aortic valve disease progression in mouse models.
• Opens new avenues for investigating AV disease etiology and testing pharmaceutical interventions.