Fig. 4

Ultrasound imaging of enthesitis. a Achilles enthesophyte in a patient with spondyloarthritis. AT, Achilles tendon; C, calcaneus. b Patellar enthesitis in a patient with psoriatic arthritis. Left, Doppler with abnormal intratendinous signal; right, enthesophyte. P, patella; PT, patellar tendon/ligament; T, tibia