Figure 1.

Longitudinal ultrasound images of the distal fibulae, taken 19 days following symptom onset. (A) Distal left fibula approximately 4 cm ‐ 8 cm superior to the lateral malleolus; malleolus on the left (white arrow). The bony cortex is visible as a horizontal hyperechoic line. (B) Distal right fibula approximately 4 cm ‐ 8 cm superior to the lateral malleolus; malleolus on the left (white arrow). A 1.90 cm long area of apparent periosteal thickening (wide yellow arrow) visible as a hypoechoic area (white arrowhead) overlying the hyperechoic bony cortex (between the white crosses). Inflammation in the soft tissues is visible as hypoechoic areas in the overlying soft tissue (bent arrow).