Morphometry and strain distribution of the C57BL/6 mouse aorta

Area of Science:

• Cardiovascular Science
• Biomechanical Engineering
• Medical Imaging

Background:

• The mouse aorta's biomechanical properties are crucial for understanding cardiovascular health and disease.
• Variations in aortic morphometry, strain, and stress along its length are not well-documented.
• Establishing a baseline in healthy mouse models is essential for future disease-related studies.

Purpose of the Study:

• To systematically document longitudinal variations in mouse aorta morphometry (diameter, wall thickness, curvature), strain, and stress.
• To validate in vivo ultrasound measurements of aortic diameter using physical casts.
• To establish a reference dataset for normal mouse aortas for future disease modeling.

Main Methods:

• In vivo ultrasound imaging (13-MHz probe) of five mice to measure aortic diameter.
• Aortic casting for validation of ultrasonic diameter measurements.
• Analysis of longitudinal variations in geometry, stress, and strain from the aortic valve to the common iliac bifurcation.

Main Results:

• Ultrasonic diameter measurements showed root mean squared and systematic errors of 12.6% and 6.4%, respectively, compared to cast measurements.
• Residual circumferential strain contributes to uniform transmural strain throughout the aorta in the loaded state.
• The incompressibility condition was validated along the length of the aorta.

Conclusions:

• This study provides a comprehensive dataset on the biomechanics of the normal mouse aorta.
• The findings highlight the role of residual strain in maintaining aortic uniformity.
• The data serves as a critical reference for investigating aortic diseases in genetically modified mouse models.