Imaging: magnetic resonance imaging

Magnetic resonance imaging (MRI) overcomes many of the limitations associated with conventional radiography, the technique historically regarded as the gold standard in imaging of osteoarthritis (OA). MRI allows visualization of changes and pathologies in joint tissues including cartilage and the menisci, the two tissue components responsible for the indirect radiographic marker of joint space narrowing, decreasing the length of time that must elapse before disease progression can be detected. Other elements of the joint can also be analysed simultaneously: a key development in the understanding of OA. This chapter focuses on the utility of MRI in observational studies and clinical trials, detailing the available MRI techniques and quantitative/qualitative measurements, and their correlation with tissue damage. The possible future directions of MRI in OA are also discussed, with a view to its potential utility in identifying disease-modifying interventions.