[Roles of Musculoskeletal Ultrasonography in the Management of Rheumatic Diseases].

Inflammation of soft tissues and the subsequent structural damage are the characteristic features of many rheumatic conditions. However, the conventional measures to evaluate these features are not accurate, potentially causing under- and over-diagnosis or treatment. Musculoskeletal ultrasonography, on the other hand, directly visualizes features which are characteristic to rheumatic conditions, such as synovitis, tenosynovitis, bursitis, enthesitis, crystal depositions, bone erosions, and osteophytes/enthesophytes. By visualizing these key features, ultrasound facilitates a more accurate evaluation of rheumatic diseases such as rheumatoid arthritis (RA), spondyloarthropathy, crystal-induced arthritis, and osteoarthritis. For RA, we investigated the impact of ultrasound on the 2010 ACR/EULAR RA classification criteria when joint involvement was determined. We assessed 109 patients with early arthritis using ultrasound. When the presence of joint swelling and number of involved joints were determined by ultrasound, the classification of RA was different from that without ultrasound in approximately 20% of the patients. Moreover, the accuracy of the classification to identify patients who required methotrexate treatment within a year improved by ultrasound. In addition, we and other investigators demonstrated the advantage of ultrasound over conventional measures in the assessment of disease activity of RA. Ultrasound also supports the education of both physicians and patients and communication between them. The utilization of musculoskeletal ultrasonography in more hospitals and clinics is expected to improve the quality of daily practice for rheumatic diseases.