Imaging of Synovitis in Osteoarthritis: Current Status and Outlook

• Published in: Seminars in arthritis and rheumatism Vol. 41; no. 2; pp. 116 - 130
• Main Authors: Hayashi, Daichi, MBBS, Roemer, Frank W., MD, Katur, Avinash, MBBS, DNB, Felson, David T., MD, MPH, Yang, Seoung-Oh, MD, Alomran, Faris, MD, Guermazi, Ali, MD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.10.2011; Elsevier
• Subjects: Biological and medical sciences; Diagnostic Imaging; Diseases of the osteoarticular system; hand; Hand Joints - diagnostic imaging; Hand Joints - pathology; Humans; imaging; knee; Knee Joint - diagnostic imaging; Knee Joint - pathology; Medical sciences; Miscellaneous. Osteoarticular involvement in other diseases; MRI; Osteoarthritis; Osteoarthritis - diagnosis; Osteoarthritis - diagnostic imaging; Osteoarthritis - pathology; Radiography; Rheumatology; Synovial Membrane - diagnostic imaging; Synovial Membrane - pathology; synovitis; Synovitis - diagnosis; Synovitis - diagnostic imaging; Synovitis - pathology; Ultrasonography; ultrasound; knee; OA; MRI; synovitis; imaging; ultrasound; hand; Knee; Synovitis; Diseases of the osteoarticular system; Rheumatology; Nuclear magnetic resonance imaging; Hand; Arthropathy; Medical imagery; Degenerative disease; Osteoarthritis; Ultrasound
• ISSN: 0049-0172; 1532-866X
• DOI: 10.1016/j.semarthrit.2010.12.003

Objectives This review article provides an overview of the current state of imaging of synovitis in osteoarthritis (OA), looking at recent advances and controversies and focusing particularly on the application of ultrasound and magnetic resonance imaging (MRI) in the assessment of the hand and knee joint. Computed tomography and nuclear medicine including positron emission tomography are also briefly discussed. Methods PubMed and MEDLINE search for articles published up to 2010, using the keywords synovitis, osteoarthritis, rheumatoid arthritis, pathogenesis, imaging, radiography, computed tomography, nuclear medicine, magnetic resonance imaging, ultrasound, and pain. Results Synovitis is defined as inflammation of the synovial membrane. Modern imaging techniques have demonstrated that synovial pathology is common in the early and late stages of OA and may be associated with pain. The current standard for OA imaging in clinical practice is conventional radiography but it does not allow direct visualization of synovitis. MRI without contrast administration, although widely used in clinical studies, cannot assess synovitis directly. Contrast-enhanced MRI and ultrasound, however, both allow direct visualization of synovitis including early inflammatory changes. They are regularly used to image synovitis in rheumatoid arthritis and increasingly in OA. Conclusions Synovitis is increasingly recognized as an important feature of the pathophysiology of OA, although there is conflicting evidence with respect to its association with disease severity and clinical parameters. Contrast-enhanced MRI and ultrasound are the most important methods for assessing synovitis associated with OA.