Table 1: Definitions of Grade 0-4 Scores for the Semiquantitative Synovial Score

Grade 0 No Visible Hypoechoic Tissue
Grade 1 Hypoechoic thickening between the bones that form a joint, not exceeding a line drawn between the tops of the bones
Grade 2 Hypoechoic thickening visible above the line drawn between the tops of the bones that form a joint, but that does not extend to overlie the diaphysis of either bone
Grade 3 Hypoechoic thickening that extends to overlie either the proximal or distal diaphysis of one of the bones
Grade 4 Hypoechoic thickening that extends to overlie both the proximal and distal diaphysis of the bones