Imaging Analysis of Circular Sclerotic Rim in Fibrous Dysplasia of Bone

Objective To study imaging manifestation of the "circular sclerotic rim" sign in fibrous dysplasia of bone. Materials and Methods 62 cases with FDB proved by surgery or pathology from 2001 to 2007 in our hospital were reviewed.17 cases(27.4%)of them had obvious circular sclerotic rim. All of the 17 cases were examined by X plain film,15 cases by CT scan and 2 by MRI scan. The radiological features of 1 case was compared with pathologic examination. Results All of the 17 cases FDB with circular sclerotic rim were monostotic lesion.13 lesions of them were located in femoral neck,1 in the distal end of the femur,3 in ilium. Integrity sclerotic rim around the lesions were indicated in 17 cases by plain film and CT scan,whose thickness were varying,and the density of center areas of the lesions seems be heterogeneous. All of the 17 cases appeared as hypointensity on T1WI and variable intensity on T2WI. The sclerotic rim is fully-grown bone tissue. Conclusion Circular sclerotic rim is one of imaging characterisics of FDB,which is helpful for diagnosis and differentiate diagnosis of the disease.