FIBROUS DYSPLASIA - MR-IMAGING CHARACTERISTICS WITH RADIOPATHOLOGIC CORRELATION

OBJECTIVE. The purpose of this study was to describe the findings of M R imaging of fibrous dysplasia and to evaluate the correlation between radiologic and pathologic findings. MATERIALS AND METHODS. MR images of 13 proven cases of fibrous dysplasia were analyzed for signal inten sity, hypointense rind, internal septations, cystic changes, soft-tiss ue extension, and patterns of contrast enhancement. RESULTS. All cases of fibrous dysplasia showed low signal intensity on T1-weighted MR im ages. Five cases (38%) were hypointense on T2-weighted MR images, and the other eight cases (62%) were hyperintense. Hypointense rind was se en in 10 cases (77%); internal septations were seen in three cases (23 %); and cystic changes was seen in two cases (15%). Soft-tissue extens ion was observed in four cases (31%), including one case (8%) with a p athologic fracture. After gadolinium infusion, central contrast enhanc ement was noted in eight cases (73%), and peripheral rim enhancement w as noted in three cases (27%). Numerous bony trabeculae, confirmed pat hologically, caused a hypointense signal intensity on T2-weighted imag es. CONCLUSION. Patients with fibrous dysplasia showed a correlation b etween radiologic and pathologic findings. Our results showed that T1- weighted images reveal fibrous dysplasia as hypointense, and T2-weight ed images reveal fibrous dysplasia as either hyperintense or hypointen se. Signal intensity on T1- and T2-weighted images and the degree of c ontrast enhancement on T1-weighted images depended on the amount and d egree of bony trabeculae, cellularity, collagen, and cystic and hemorr hagic changes.