Fig. 1. Ultrasound imaging (longitudinal view with power Doppler) for knee joint synovitis (a) and enthesitis of the Achilles tendon (b). The suprapatellar (arrows) and retrocalcaneal (star) bursae are distended with anechoic effusion. Peribursal synovitis is observed at both sites. P, patella; C, calcaneus; Qt, quadriceps tendon; At, Achilles tendon.