Figure 2

(a) Capsular/extracapsular changes (arrows) on power Doppler ultrasonography on the radial side of the 2nd proximal interphalangeal joint in a patient with psoriasis-associated arthritis. (b,c) The corresponding coronal T1-weighted magnetic resonance images before (b) and after (c) contrast administration showing capsular/extracapsular post-contrast enhancement. IP, intermediate phalanx; PP, proximal phalanx.