Aortic thrombi microstructure through contrast-enhanced X-ray microtomography.

The intraluminal thrombus (ILT) is a heterogeneous porous medium made up of three layers (luminal, medial, abluminal), found in most abdominal aortic aneurysms (AAA). Few morphological studies exist, and its role in disease progression remains controversial. Histological investigations suggest a harmful effect, leading to aortic wall hypoxia and potential rupture. However, 2D morphological studies cannot provide precise answers due to the complexity of ILT porosity. This study aims to provide reliable quantitative 3D morphological data using contrast-enhanced X-ray micro-computed tomography (micro-CT). We propose a validation pipeline for micro-CT image segmentation using virtual tomography. Our results show a decrease in porosity from the luminal to the abluminal layer, with similar pore diameters but more interconnected pores in the luminal region. The size of interconnected pores around 15-20 [Formula: see text] suggests cell passage is facilitated through the ILT's porous network. Finally, pore anisotropy was observed across the ILT thickness. This work suggests further studies on ILT permeability to validate its involvement in wall hypoxia.