The current state of computed tomography in osteoarthritis research

CT has evolved into a complementary tool for three-dimensional (3-D) structural assessment in OA research. This review highlights advances across key domains of CT-based OA imaging: structural features, shape modeling, alignment, contact stress modeling, bone morphometry and BMD, articular cartilage, meniscus, and combination with other modalities. CT's high-resolution bone visualization enables accurate quantification of osteophytes, subchondral bone cysts, and sclerosis, as well as precise measurement of joint space width (JSW). The high geometric fidelity of CT also facilitates 3-D bone shape modeling. Additionally, CT supports dynamic evaluation of joint mechanics, including articular contact stress estimates. Weight-bearing CT enables functional assessment of joint alignment and JSW under physiologic loads. QCT, HR-pQCT, and micro-CT support detailed analysis of periarticular bone morphometry and BMD, capturing microarchitectural changes linked to OA severity. CT arthrography provides high-contrast visualization of articular cartilage and has shown superior sensitivity over MRI for detecting cartilage and meniscal defects. Dual-energy CT enables material differentiation, offering a noninvasive alternative to arthrocentesis. Spectral photon-counting CT combines ultra-high spatial resolution with multi-energy tissue characterization, improving the accuracy of compositional and structural assessment. Moreover, CT provides the anatomical framework for hybrid imaging modalities, such as PET CT and SPECT CT, which can assess bone metabolic activity. Together, these emerging CT modalities allow detailed 3-D analysis of bone geometry and subchondral changes, as well as evaluation of cartilage thickness and meniscal integrity, alongside accurate 3-D alignment measurements. These advances establish CT as a versatile platform for developing OA imaging biomarkers, monitoring disease progression, and enhancing clinical trial outcomes. Insights gained from these technologies will continue to inform future OA research and guide clinical decision-making.