Paget disease of the calvaria and facial bones with an osteosarcoma of the maxilla: CT and MR findings.

The CT and magnetic resonance (MR) findings of Paget disease of the calvaria and facial bones are described and compared with one another. The sites of dense, woven bone, myeloid marrow, and background Paget matrix can be clearly identified. A rare case of Paget sarcoma (osteogenic sarcoma) of the facial bones is also presented. The distinction between this sarcoma and the Paget bone was clearer on CT than on MR. This presumably is because the bone is directly seen on CT and only indirectly imaged on MR.