Imaging of osteoarthritis: update from a radiological perspective.

PURPOSE OF REVIEW: Imaging plays an increasingly important role in the continuing effort to understand the pathogenesis of osteoarthritis and in the quest for disease-modifying osteoarthritis drugs. To assist investigators in choosing the appropriate imaging technique for a particular goal of a study, this review describes, from a radiological point of view, key studies that were published between May 2010 and May 2011. RECENT
FINDINGS: MRI and ultrasound are the two key modalities for osteoarthritis research today. MRI offers semiquantitative, quantitative and compositional assessment. The importance of contrast-enhanced MRI for synovitis assessment has been demonstrated by several studies. Radiography still has a role in clinical trials in light of regulatory requirements, but investigators need to be aware of its inherent limitations. MRI is the best modality for imaging of osteoarthritis: its strengths and unique advantages include ability to visualize multiple individual tissue pathologies relating to pain and also to predict clinical outcome.
SUMMARY: MRI enables multitissue morphologic and compositional assessment of the joint. Contrast-enhanced MRI is essential for evaluation of synovitis in knee osteoarthritis. Ultrasound is a useful technique for assessing synovitis and structural damage especially in hand osteoarthritis.