Fig. 1

a. Synovitis at the MCP joint of the clinically dominant hand. Dorsal view in a longitudinal scan of the MCP joint. A moderate joint cavity widening with signs of synovial proliferation and PD signal (grade 3) is appreciated. MC = metacarpal head; PP = proximal phalanx; Tendon = common digital extensor tendon. b. Tenosynovitis at the first extensor compartment of the clinically dominant hand. Longitudinal scan that shows the image with PD technique, where an inflammatory process of the intra-synovial sheath consistent with tenosynovitis is appreciated along with a correlation with the area in the tendon and the anatomical damage. c. Bone erosion at the MC2 head. Longitudinal (upper image) and transversal (bottom image) planes. There is a bone surface interruption (arrow) in 2 perpendicular planes (longitudinal and transversal)