Figure 29. Tibialis posterior tendinosis. (a) Axial ultrasound showing a minor widening of the tendon (arrow) with a hypoechoic rim representing tenosynovitis (open arrow). (b) Longitudinal section shows a widened tendon with fluid in the tendon sheath (arrow) and synovial hypertrophy (open arrow). (c) Power Doppler shows hypervascularity in the tendon and surrounding synovium.