![The radiographic appearance of fibrous dysplasia (FD) and the rind sign. a–e Frontal radiographs demonstrate classic FD lesions in appendicular skeleton. A classic lucent lesion surrounded by a layer of sclerotic reactive bone (so-called the rind sign). The rind sign is most commonly seen in the proximal femur (red arrow)

Kushchayeva, Y.S., Kushchayev, S.V., Glushko, T.Y. et al. Fibrous dysplasia for radiologists: beyond ground glass bone matrix. Insights Imaging 9, 1035–1056 (2018). https://doi.org/10.1007/s13244-018-0666-6](attachment:9dfe702e-1dc8-4f6a-ad9b-8714c6aab000:rind_sign.webp)

The radiographic appearance of fibrous dysplasia (FD) and the rind sign. a–e Frontal radiographs demonstrate classic FD lesions in appendicular skeleton. A classic lucent lesion surrounded by a layer of sclerotic reactive bone (so-called the rind sign). The rind sign is most commonly seen in the proximal femur (red arrow)

Kushchayeva, Y.S., Kushchayev, S.V., Glushko, T.Y. et al. Fibrous dysplasia for radiologists: beyond ground glass bone matrix. Insights Imaging 9, 1035–1056 (2018). https://doi.org/10.1007/s13244-018-0666-6