Toward imaging biomarkers for osteoarthritis.

Many new therapeutic strategies have been and are being developed to correct, prevent, or slow the progression of osteoarthritis. Our ability to evaluate the efficacy of these techniques, or to determine the situations for which they might provide the most benefit, critically depends on diagnostic measures that can serve as proxies for the present or predicted state of the cartilage. Many of the magnetic resonance imaging techniques that have been emerging over the past decades appear promising in that they have shown technical validity in measuring the morphologic and molecular state of cartilage. With continued development and added insight from pilot clinical studies, these or related methods may soon be in customary use. These techniques are part of a paradigm shift where therapeutic strategies are developed hand-in-hand with diagnostic approaches-a shift that offers the promise of speeding development of effective therapies, and focusing their use in areas where they can be most successful.