2 / New conclusions of the thesis: At the positions of MCP II, MCP III, PIP II, PIP III, MTP II, MTP V joints: the rate of synovitis on the US7 score (89.1%; 79.7%; 87.5%; 88.3%; 78.1%; 74.2%) were higher than the proportion of swelling or joint pain on clinical manifestations (34.3%; 32.8%; 37.5%; 30.5%; 25.0%; 16.4%) (p <0.001).