3D reconstruction of elastin fibres in coronary adventitia

• Published in: Journal of microscopy (Oxford) Vol. 265; no. 1; pp. 121 - 131
• Main Authors: LUO, T., CHEN, H., KASSAB, G.S.
• Format: Journal Article
• Language: English
• Published: England Wiley Subscription Services, Inc 01.01.2017
• Subjects: 3D reconstruction; Adventitia - chemistry; Animals; Computational Biology; Coronary Vessels - chemistry; Elastin - analysis; elastin fibre; image analysis; Imaging, Three-Dimensional; multiphoton microscopy; Swine; 3D reconstruction; image analysis; multiphoton microscopy; elastin fibre
• ISSN: 0022-2720; 1365-2818; 1365-2818
• DOI: 10.1111/jmi.12470

Summary A 3D reconstruction of individual fibres in vascular tissue is necessary to understand the microstructure properties of the vessel wall.  The objective of this study is to determine the 3D microstructure of elastin fibres in the adventitia of coronary arteries.  Quantification of fibre geometry is challenging due to the complex interwoven structure of the fibres.  In particular, accurate linking of gaps remains a significant challenge, and complex features such as long gaps and interwoven fibres have not been adequately addressed by current fibre reconstruction algorithms.  We use a novel line Laplacian deformation method, which better deals with fibre shape uncertainty to reconstruct elastin fibres in the coronary adventitia of five swine. A cost function, based on entropy and Euler Spiral, was used in the shortest path search. We find that mean diameter of elastin fibres is 1.67 ± 1.42 μm and fibre orientation is clustered around two major angles of 8.9˚ and 81.8˚.  Comparing with CT‐FIRE, we find that our method gives more accurate estimation of fibre width.  To our knowledge, the measurements obtained using our algorithm represent the first investigation focused on the reconstruction of full elastin fibre length.  Our data provide a foundation for a 3D microstructural model of the coronary adventitia to elucidate the structure–function relationship of elastin fibres. Lay description A 3D reconstruction of individual fibres in vascular tissue is necessary to understand the microstructural properties of the vessel wall. The objective of this study is to determine the 3D microstructure of elastin fibres in the adventitia of coronary arteries. We used previously published multiphoton microscopy data from five swine to reconstruct the elastin fibre microstructure in the coronary artery adventitia. The geometric reconstruction of the elastin fibres was made based on two main approaches: (1) skeleton extraction and fibre segments linking and (2) region growing to individual fibres. Voronoi diagram (a region decomposition technique that partitions the image into smaller convex polygons to separate each fibre segment) was designed to analyse the parallel and collinear fibre segments. The polygon boundary was located at the middle position for each segment pair and Laplace line deformation was used to connect segment gap. A cost function, based on information entropy and Euler Spiral curve, was used in the shortest path search. A 3D reconstruction of elastin fibres demonstrated the capabilities of the procedures for complex fibre structures. The morphometric features of width and orientation were measured, and the mean diameter of elastin fibres was found to be 1.67 ± 1.42 μm and a median of 1.53μm (n = 5 vessels). The orientation of the elastin fibres revealed two major angles of 8.9o and 81.8o (n = 5 vessels with >10 000 measurements). These data provide a foundation for a 3D microstructural model of the coronary adventitia to elucidate the structure–function relation of elastin fibres.