Contrast-enhanced intravascular ultrasound 3D reconstruction of a vasa vasorum mimicking model

It is increasingly recognized that the development of new microvessels (vasa vasorum) within and surrounding atherosclerotic plaques is essential to enable artery lesion growth and plays a central role in rendering it vulnerable to rupture. Currently, there is no established clinical technique capable of imaging the vasa vasorum (VV) in the coronary arteries of humans. It has been shown that contrast-enhanced intravascular ultrasound (CE-IVUS) is capable of imaging VV in vivo. This study aims at reconstructing in three dimensions (3D) a VV model using CE-IVUS with a clinical coronary imaging catheter. A polyvinyl alcohol based VV model was manufactured, exhibiting a VV mimicking branch pattern with a diameter ranging from 200 to 100 μm. After perfusion of the VV model with the ultrasound contrast agent Definity^®, a manual pullback consisting of 93 cross sectional IVUS images spaced every 200 μm was performed. Perfused areas were segmented in two registered CE-IVUS planes and compared to coregistered 10 μm thick slices of the VV model. The VV mimicking microchannel diameters measured with CE-IVUS agreed within 30% with the slice diameters. As CE-IVUS imaging can be carried out in-vivo, this method could be used during clinical IVUS investigations as an additional diagnostic for plaque vulnerability.