Advances in Medical Imaging for the Diagnosis and Treatment of Osteoarthritis

Abstract

Osteoarthritis (OA) is a leading cause of joint pain and functional impairment in middle-aged and elderly populations. Because its pathology involves whole-joint structures—including cartilage, subchondral bone, synovium, menisci, and ligaments—a single imaging modality is insufficient for a comprehensive evaluation. Focusing on knee OA, this review summarizes the applications of radiography (X-ray), multi-slice spiral computed tomography (MSCT), ultrasound, magnetic resonance imaging (MRI), and nuclear medicine imaging in OA diagnosis, clinical decision-making, interventional guidance, and therapeutic efficacy evaluation. Radiography serves as the cornerstone for Kellgren-Lawrence (K-L) grading, joint space width measurement, and lower limb alignment assessment. MSCT clearly delineates subchondral bone sclerosis, osteophytes, and subchondral cysts while enabling three-dimensional measurements. Ultrasound is well-suited for assessing joint effusion and synovial hypertrophy, as well as guiding arthrocentesis and intra-articular injections. MRI provides a comprehensive visualization of cartilage, bone marrow lesions (BMLs), menisci, and ligaments, serving as a vital tool for early diagnosis and treatment monitoring. Nuclear medicine imaging reflects bone metabolism and inflammatory activity. Two single-center studies have demonstrated that combining MSCT with MRI yields higher diagnostic accuracy for knee OA than either modality alone. Currently, available evidence is primarily derived from small-sample retrospective studies, and evaluation criteria remain unstandardized. Multimodal fusion, quantitative imaging, and artificial intelligence represent key directions for future development.