In-vivo biomechanical characteristics analysis of ascending aortic aneurysm using multidimensional dynamic CTA

Area of Science:

• Cardiovascular Imaging and Biomechanics
• Medical Engineering
• Aortic Disease Research

Background:

• Ascending thoracic aortic aneurysms (ATAA) pose a significant rupture risk.
• Accurate biomechanical assessment of ATAA is crucial for risk stratification.
• Current methods may not fully capture the complex mechanical behavior of the ascending aorta.

Purpose of the Study:

• To analyze the biomechanical characteristics of ATAA using multidimensional dynamic computed tomography angiography (MD-CTA).
• To evaluate novel biomechanical parameters for assessing ATAA wall mechanics and energy storage.
• To differentiate biomechanical profiles in non-Marfan ATAA, Marfan syndrome, and healthy individuals.

Main Methods:

• Reconstruction of aortic models from MD-CTA images for 30 subjects (20 ATAA patients, 10 controls).
• Application of the inverse finite element method (iFEM) to calculate wall tension and strain.
• Calculation of strain-stiffness index (SSI), dynamic SSI (dSSI), potential energy reserve index (PERI), and strain resistance (Rs).

Main Results:

• SSI and dSSI were significantly higher in the non-Marfan ATAA group versus Marfan and control groups.
• PERI and Rs were elevated in the non-Marfan ATAA group compared to controls, with significance noted.
• No significant differences in biomechanical markers were found between Marfan and control groups.

Conclusions:

• Novel biomechanical markers (SSI, dSSI, PERI, Rs) derived from MD-CTA show potential for ATAA assessment.
• These markers may help differentiate biomechanical properties in various ATAA patient subgroups.
• Further validation could establish these markers as complementary tools for patient-specific rupture risk evaluation.