Experimental Insight into the Hemodynamics and Perfusion of Radiological Contrast in Patent and Non-patent Aortic...

Area of Science:

• Cardiovascular fluid dynamics
• Medical imaging physics
• Biomedical engineering

Background:

• Normal aortic arch flow exhibits velocity skewing towards inner and outer walls along the curve.
• Aortic dissection (AD) involves blood flow alterations in the true lumen (TL) and false lumen (FL).
• Flow velocity in FL impacts hemodynamic loading, tearing risk, and contrast agent perfusion in diagnostic imaging.

Purpose of the Study:

• To investigate how AD morphology and configuration affect blood velocity fields in TL and FL.
• To analyze the relative perfusion of radiological contrast agents through the dissection.
• To understand the influence of entry tear proximity on flow dynamics.

Main Methods:

• Utilized eight in vitro models of aortic dissection, including patent and non-patent false lumen configurations.
• Employed Particle Image Velocimetry (PIV) for quantifying AD velocity fields.
• Implemented Laser-Induced Fluorescence (LIF) for visualizing flow phenomena and quantifying dye perfusion, mimicking contrast-enhanced CT.

Main Results:

• Entry tear location and size combination significantly influenced TL vs. FL velocity dominance.
• Smaller tears limited maximal FL flow velocity; merging tears created vortices.
• Non-patent FL showed negligible flow, while patent FL exhibited comparable dye perfusion to TL.
• Specific geometry (A1R) with downstream tear and sufficient sizing showed highest FL velocity, indicating elevated risk.

Conclusions:

• Blood velocities in TL and FL are highly sensitive to specific AD configurations.
• Elevated FL flow velocity in certain configurations suggests increased hemodynamic loading and tearing risk.
• Time-delayed acquisition protocols are recommended for contrast-enhanced imaging of non-patent FL cases.