Photon-counting CT in musculoskeletal imaging: New horizon for understanding bone health in osteoarthritis

Osteoarthritis is a heterogeneous disease affecting many joint tissues. The significant role of bone, and in particular abnormalities in the subchondral bone, in OA is increasingly understood. Bone marrow lesions are believed to play an important role in OA symptom perception and progression of OA. Consequently, there is an increasing interest in the characterization of subchondral bone and bone marrow lesions by means of imaging. Computed tomography (CT) has shown to be a suitable imaging method to visualize various bony abnormalities in OA, however, the spatial resolution of conventional CT scanners is limited for assessing trabecular bone architecture. Photon-counting CT (PCCT) is a new CT technology that has the potential to overcome the resolution limitations of conventional CT by using a completely different detector design. In this perspective paper, we discuss the technical principles of PCCT and the advantages for imaging of musculoskeletal diseases and OA bone health in particular. We highlight initial studies applying PCCT for imaging different tissues involved in OA, including subchondral bone, and discuss the potential of PCCT in advancing clinical OA research.