Evaluating Non-destructive X-ray-based 3D Histology Using Contrast-Enhanced Micro-CT to Visualise and Quantify Vascular Elastin and Collagen.

=0.49). This highlights CECT as a non-destructive, accurate method for quantifying vascular microstructure with fewer artefacts than classical 2D histology. VH and PR staining were visually and quantitatively (±10% E-SAF and C-SAF equivalence) unaffected by CESA-staining. PTA-staining with cryopreservation caused loss of nucleic contrast, while 1:2 Hf-POM influenced ECM haematoxylin uptake, reducing nuclei visualisation and cell count accuracy in H&E histology. Both CESAs bind non-specifically but preferentially to elastin, enabling reliable quantification. However, vascular collagen remains difficult to visualise as ECM is non-specifically stained. STATEMENT OF SIGNIFICANCE: Understanding the three-dimensional microstructure of vascular tissues is crucial for revealing how it governs mechanics and disease progression. This study investigates two contrast agents, phospho-tungstic acid and 1:2 hafnium-substituted Wells-Dawson polyoxometalate, for their potential to visualise and quantify two of the key constituents within arterial tissue, collagen and elastin, using Contrast-Enhanced Micro-focus Computed Tomography (CECT). By assessing these agents combined with CECT as alternatives to gold-standard histological techniques for the visualisation and quantification of these key extracellular matrix components, this research advances CECT as a non-destructive alternative to traditional histological techniques. Improved three-dimensional imaging of vascular architecture deepens our understanding of arterial structure-function relationships and supports more accurate computational modelling, disease characterisation, and the development of next-generation cardiovascular devices.