In-situ deformation imaging of articular cartilage using grating-based phase-contrast X-ray CT at a synchrotron light source

Quantification of deformation behavior of artic ular cartilage (AC) is crucial for understanding its mechani cal function and response to mechanical stimuli. Here, we explored whether grating-based phase-contrast X-ray CT using monochromatic synchrotron light (grating-based msPXCT) enables in-situ quantification of local deforma tion in AC. Grating-based msPXCT of a porcine AC sample during axial compression test was conducted using a Talbot grating interferometer. Local displacements and strains were computed using a digital volume correlation method. The magnitude of axial strain decreased from the upper to middle sample zones and reached almost constant over the middle-lower zone, consistent with the depth-dependent density increase with compression. Thus, grating-based msPXCT may be suitable for quantitative analysis of AC deformation.