MR imaging of periosteal and cortical changes of bone.

The changes seen in the periosteum and cortical bone are fundamental radiographic features of bone disease. The basic radiographic findings used for diagnosis of bone lesions (patterns of cortical destruction and of periosteal new bone formation) can be well identified with magnetic resonance (MR) imaging. The authors used comparative radiographic, computed tomographic, and MR images to illustrate patterns of periosteal reaction (simple, laminated, spiculated, Codman triangle), geographic and permeative cortical destruction, cortical erosion, cortical expansion and continuity, and intraosseous and extraosseous calcification. The only feature not well demonstrated by MR imaging is pattern or extent of soft-tissue calcification. Although MR images are not required for diagnosis of most peripheral bone lesions, when they are obtained, these fundamental diagnostic features should not be ignored.