Fig. 1

X-PCI-CT sagittal images of the healthy cartilage tissue acquired at different spatial resolutions. Arrows indicate chondrocytes. A X-PCI-CT image (6.1 × 6.1 × 6.1 µm3 voxel size, 60 keV X-rays, single distance) providing an overview of the cartilage tissue with its different layers: the star indicates the subchondral bone. B X-PCI-CT image (0.7 × 0.7 × 0.7 µm3 voxel size, filtered polychromatic X-ray beam, single distance) of a sub-region within the cartilage (blue rectangle in A), where numerous chondrocytes are visible. C X-PCI-CT image (0.1 × 0.1 × 0.1 µm3 voxel size, 17 keV X-rays, nano-holotomography) showing details of the cell structures within the chondrocytes and matrix components. In A + B lighter grey indicates higher densities while darker gray indicates lower tissue densities, whereas in C it is the opposite. Faint bright vertical strips visible in the nano-holotomography image (C) are artifacts from uneven surface edges caused by the cutting process during sample preparation