Fig. 5

Stress fractures and healing phases. Focal thickening of the periosteum (yellow arrowhead), the disappearance of the reverberation artifact (void arrowheads) of the cortical bone, and lamellar calcifications (white arrowhead) within the periosteum are the most common sonographic findings in the stress fractures (A, B). Using high-sensitive color Doppler to follow up the healing phases of the stress fracture, microvasculature (red arrowheads) within the thickened periosteum (yellow arrowhead) (C) and penetrating vessels (orange arrowheads) crossing through the cortical bone (D) can be observed