Shear wave elastography is a rapidly evolving US imaging technique that allows quantification of mechanical and elastic tissue properties and serves as an adjunct to conventional US techniques, aiding in initial characterization and treatment follow-up of various traumatic and pathologic conditions of the musculoskeletal system. In the past 2 decades, sonoelastography has been progressively used as a tool to help evaluate soft-tissue elasticity and add to information obtained with conventional gray-scale and Doppler ultrasonographic techniques. Recently introduced on clinical scanners, shear-wave elastography (SWE) is considered to be more objective, quantitative, and reproducible than compression sonoelastography with increasing applications to the musculoskeletal system. High resolution ultrasonography is an excellent and cost effective modality for early diagnosis of inflammatory arthritis. It detects mild synovitis when clinical examination is equivocal. The major abnormalities of RA appear in the synovial joints as soft tissue swelling caused by synovial hypertrophy, effusion, bursal and tendon sheath swelling. Marginal erosions are due to inflamed synovium destroying the cortex and underlying bone and they occur initially at the bare area: the margins where synovium is not covered by cartilage.