CT and MRI of fibrous dysplasia of the spine

Abstract

The purpose of this study was to present the CT and MRI findings of patients with fibrous dysplasia (FD) of the spine. Among the patients with pathologically proven skeletal FD, 12 (8 males and 4 females; mean age, 43 years) who were evaluated with either spine CT or MRI were included. The number and location of the involved vertebral segments, the presence of lytic lesions, ground-glass opacity (GGO), an expansile nature, cortical disruption, a sclerotic rim, a decrease in body height and contour deformity were examined on CT scans (n=12), while signal intensity, enhancement patterns and the presence of a dark signal rim on the lesion were examined using MRI (n=9). Nine patients had polyostotic FD, including one with an isolated spinal localisation, while three had monostotic FD. An expansile nature (n=3) and osteolytic lesions with GGO (n=3) were seen. On CT images, GGO was noted in all patients. An expansile nature (n=11) and presence of lytic lesions (n=11) were noted. A decrease in body height (n=9) and sclerotic rim formation (n=9) were indicated. Contour deformities were visible in six patients. The MRI findings were non-specific. Dark signal rims were visible on MRI in seven patients. Typical imaging findings of extraspinal FD were noted on spine CT scans. These characteristic CT imaging findings of spinal FD may be helpful in differentiating FD from other common spine diseases.