Fig. 11

Osteosarcoma. Secondary, “pagetic.” T1WI post-contrast (a and b). Aggressive, destructive, giant, and transdiploic lesion with extensive intra- and extracranial soft-tissue component containing iso to hypointense areas of probable necrosis (arrows in a and b) and deeply hypointense foci of suspected bone matrix (dashed arrows in b). Note the underlying abnormal calvarial bone with diffuse expansion, cortical thickening and heterogeneous multifocal variable signal intensity, and enhancement (arrowheads) consistent with Paget disease