Advanced imaging of early rheumatoid arthritis

MR imaging plays an invaluable role in the early diagnosis and management of rheumatoid arthritis (RA). The pathologic processes in RA involve synovitis, joint effusion, proliferation of fibrovascular connective tissue, and the formation of pannus. MR imaging provides high sensitivity in detecting inflammatory changes in joints. Several studies report high intraobserver and interobserver reliability and low variation for MR imaging. MR imaging allows detection, and in some cases, quantification of synovial changes. Dynamic MR imaging is a new technique that uses rate of synovial enhancement in evaluation of inflammatory changes. MR imaging allows visualization of erosions in three orthogonal planes and has much greater sensitivity than radiography in detecting erosions. Use of a contrast agent further increases the sensitivity in detecting erosions and differentiates synovial proliferation from fluid. Other manifestations of RA, such as intraosseous cysts, tenosynovitis, bone marrow edema, and carpal tunnel syndrome can also be visualized on MR images. MR imaging assists in the early detection of RA, which allows earlier initiation of treatment with disease modifying therapies.