Magnetic resonance imaging appearances of fibrous dysplasia.

Fibrous dysplasia is a developmental disorder in which normal bone marrow is replaced by fibro-osseous tissue. The radiographic, CT and scintigraphic appearances of this condition are well known. The MRI appearances of fibrous dysplasia have not been widely published. The lesions are largely isointense with areas of hypointensity on T(1) weighted images and appear heterogeneously hyperintense on T(2) weighted images. The enhancement pattern is patchy central, rim, homogeneous, or a combination. The MRI features reflect the variable tissue components of this entity. This pictorial review aims at highlighting the MRI appearances, with pathological correlation.