Overview: new methods in imaging osteoarthritis.

The new imaging modalities, namely computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography (US) provide potentially powerful tools for in vivo assessment of osteoarthritis (OA), monitoring the progress of the disease and understanding its natural course. However, to use these tools effectively, we need more prospective research focused on correlating imaging data with biochemical and gross and microscopic pathologic findings. MRI is clearly the most powerful tool for demonstrating the various articular components which may be affected in OA. CT is excellent for delineating osseous abnormalities and with US we are able to evaluate the thickness and surface characteristics of those portions of articular cartilage that are accessible. The advantages and limitations of these 3 modalities are discussed as they pertain to OA of the hip and knee.