Imaging in Osteoarthritis.

With technologic advances and the availability of sophisticated computer software and analytical strategies, imaging plays an increasingly important role in understanding the disease process of osteoarthritis (OA). Radiography has limitations in that it can visualize only limited features of OA, such as osteophytes and joint space narrowing, but remains the most commonly used modality for establishing an imaging-based diagnosis of OA. This article describes the roles and limitations of different imaging modalities and discusses the optimum imaging protocol, imaging diagnostic criteria of OA, differential diagnoses, and what the referring physician needs to know.