Enthesitis of Achilles tendon in a longitudinal scan

Enthesitis of Achilles tendon in a longitudinal scan (left part of the image: cranial). Calcaneal bone (C), Achilles tendon margins (thick arrows), calcaneal bone (C), presence of erosions (thin arrows), enthesophyte (bone spur; E), hypoechogenicity (A), and Doppler signal (PD) of enthesis (tendon insertion).