Epiphyseal growth arrest lines. MR findings.

We present two cases in which MR exams revealed unusual, low signal intensity lines in the marrow space of epiphyses. These epiphyseal lines were smooth and regular, creating a bone-in-bone appearance. These lines were much more conspicuous on MR than on radiographs, partly because of adjacent alterations in trabecular architecture. A history of prolonged immobilization during childhood in both cases suggests that these lines represent growth arrest lines persisting in the epiphyses.