Contrast-enhanced x-ray microscopy of articular cartilage.

This study evaluates articular cartilage structure ex vivo using both techniques. Osteochondral plugs were excised from non-diseased bovine knees and stained in phosphotungstic acid for 0 to 32 hours. XRM imaging revealed an optimal staining time of 16 hrs and a saturated staining time of 24 hrs. Histology sections were cut and analysed by polarized light microscopy (PLM) and second-harmonic-generation dual-photon (SHG-DP) microscopy. Histology photomicrographs were aligned with matching XRM slices, and evaluated for features relevant in histopathological scoring of osteoarthritis cartilage, including the tidemark, collagen architecture and chondrocyte morphology. The cartilage collagen network and chondrocytes from the 3D contrast-enhanced XRM were correlated with the 2D histology. This technique has two distinct advantages over routine histopathology: (1) the avoidance of dehydration, demineralization, and deformation of histological sectioning, thereby preserving the intact articular cartilage and subchondral bone plate ex vivo, and (2) the ability to evaluate the entire osteochondral volume in 3D. This work explores several diagnostic features of imaging cartilage, including: visualization of the tidemark in XRM and SHG-DP microscopy, validating the morphology of chondrocytes and nuclei with XRM, SHG-DP and PLM, and correlating collagen birefringence with XRM image intensity. PMID: 32814448 [PubMed - as supplied by publisher]
Source: Connective Tissue Research - Category: Research Tags: Connect Tissue Res Source Type: research