Fig. 9
From: Lesions involving the outer surface of the bone in children: a pictorial review
Heterotopic ossification in an 18-year-old boy. Lateral radiograph of the femur a shows an ossifying lesion adjacent to but distinct from the lateral aspect of the proximal femoral cortex (arrow). Sagittal T1-weighted MRI b demonstrates heterogeneously low signal through this region. Axial T1-weighted post-contrast image obtained at this level c shows associated enhancement (arrow). There was a history of trauma