Technical note: Cartilage imaging with sub-cellular resolution using a laboratory-based phase-contrast x-ray microscope

Esposito, M; Astolfo, A; Cipiccia, S; Jones, CM; Savvidis, S; Ferrara, JD; Endrizzi, M; Dudhia, J; Olivo, A

Abstract

BackgroundMicroscopic imaging of cartilage is a key tool for the study and development of treatments for osteoarthritis. When cellular and sub-cellular resolution is required, histology remains the gold standard approach, albeit limited by the lack of volumetric information as well as by processing artifacts. Cartilage imaging with the sub-cellular resolution has only been demonstrated in the synchrotron environment. PurposeTo provide a proof-of-concept demonstration of the capability of a laboratory-based x-ray phase-contrast microscope to resolve sub-cellular features in a cartilage sample. MethodsThis work is based on a laboratory-based x-ray microscope using intensity-modulation masks. The structured nature of the beam, resulting from the mask apertures, allows the retrieval of three contrast channels, namely, transmission, refraction and dark-field, with resolution depending only on the mask aperture width. An ex vivo equine cartilage sample was imaged with the x-ray microscope and results were validated with synchrotron tomography and histology. ResultsIndividual chondrocytes, that is, cells responsible for cartilage formation, could be detected with the laboratory-based microscope. The complementarity of the three retrieved contrast channels allowed the detection of sub-cellular features in the chondrocytes. ConclusionsWe provide the first proof-of-concept of imaging cartilage tissue with sub-cellular resolution using a laboratory-based x-ray microscope.

Citation

Esposito, M., Astolfo, A., Cipiccia, S., Jones, C., Savvidis, S., Ferrara, J., …Olivo, A. (2023). Technical note: Cartilage imaging with sub-cellular resolution using a laboratory-based phase-contrast x-ray microscope. Medical Physics, https://doi.org/10.1002/mp.16599

• Journal Article Type: Article
• Acceptance Date: Jun 12, 2023
• Publication Date: Jul 11, 2023
• Deposit Date: Aug 1, 2023
• Publicly Available Date: Aug 1, 2023
• Print ISSN: 0094-2405
• Publisher: American Association of Physicists in Medicine
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1002/mp.16599
• Keywords: cartilage imaging; cellular imaging; dark-field; phase-contrast imaging; soft tissue imaging; x-ray microscopy; COMPUTED-TOMOGRAPHY; ARTICULAR-CARTILAGE