Morphological and dynamic analysis of the normal aortic valve with 4D computed tomography

Area of Science:

• Cardiovascular imaging
• Anatomical morphometrics
• Cardiac cycle dynamics

Background:

• Accurate aortic root dimensions are vital for cardiovascular procedures.
• Traditional 2D measurements may not fully capture the dynamic nature of the aortic annulus.

Purpose of the Study:

• To evaluate precise aortic root and annulus dimensions during the cardiac cycle using multiphase cardiac CT.
• To assess the feasibility and reproducibility of this novel 4D reconstruction method.

Main Methods:

• Analysis of 30 ECG-gated multiphase cardiac CT scans of patients with normal tricuspid aortic valves.
• In-house software used for 3D reconstruction and interpolation of aortic annulus border points across 10 cardiac phases.
• Generation of multiple planes including left ventricular outflow tract, Valsalva sinuses, and sinotubular junction.

Main Results:

• Mean 3D aortic annulus area was 7.67 cm², with a mean 2D diameter of 2.51 cm.
• Global area and perimeter expansion during the cardiac cycle were 11.8% and 7.1%, respectively.
• 3D analysis revealed significant underestimation of annulus dimensions by virtual basal ring measurements.

Conclusions:

• 4D morphometric analysis provides precise and reproducible evaluation of the aortic annulus.
• The aortic annulus and root are dynamic, deformable structures with a specific expansion sequence during the cardiac cycle.
• These findings are important for procedural planning in cardiovascular interventions.