The CT Appearances Analysis For Fibrous Dysplasia Of Bone Located At Rare Sites

Objective:To investigate the CT appearances of fibrous dysplasia of bone located at rare sites through comparing and observing fundamental CT imaging signs of fibrous dysplasia of bone located at rare sites and frequent sites,to enhence the cognition about fibrous dysplasia of bone eventually.Materials and Methods:Imaging and clinic findings in 68 cases with pathologically confirmed fibrous dysplasia of bone were reviewed retrospectively. There are 21 cases in investigative group,In all 21 cases,the lesions of 7 cases were in vertebra,7 cases were in plat bone,4 cases were in short tubiform bone,and the lesions of 3 cases were in clavicle,pubic bone,astragulus.In all the 47 cases of control group,the lesions of 37 cases were in long bone,10 cases were in costal bone.CT appearances of both investigative group and control group were analyzed and observed,indicatrix observed included cystic bone destructions,lucent area,"ground glass"-like density,calcification,sclerotic border,internal septation and shape abnormality of bone involved.The data concerned was collected.At last,to compare differences of occurrence concerning all the imaging signs(cystic bone destructions, lucent area,"ground glass"-like density,calcification,sclerotic border,internal septation and shape abnormality of bone involved)between investigative group and control group by using Fisher Exact Test,The relative marked CT features of fibrous dysplasia at rare sites were summarized eventually.Results:(1)There were no statistically significant differences between investigative group and control group in occurrence concerning cystic bone destructions,lucent area,"ground glass"-like density,calcification,sclerotic border, internal septation(P＞0.05).There was statistically significant difference in shape abnormality of bone between investigative group and control group(P＜0.05).(2) Body of vertebra was involved chiefly in all the 7 cases of fibrous dysplasia located in vertebra."ground glass"-like density,calcification,and sclerotic border were frequent appearances in the lesions located in vertebra,There were statistically significant differences in"ground glass"-like density and calcification between investigative group and control group(P＜0.05).Shape abnormality of bone was a rare imaging sign in fibrous dysplasia of bone cases at vertebra,and there was a statistically significant difference in shape abnormality of bone between investigative group and control group.(3)For the cases of fibrous dysplasia of bone located in plat bone,of all the imaging signs(cystic bone destructions,lucent area,"ground glass"-like density, calcification,sclerotic border,internal septation and shape abnormality of bone involved) There were no statistically significant differences in occurrence between investigative group and control group.(P＞0.05)(4)"Ground glass"-like density was a frequent imaging sign in the cases of fibrous dysplasia at short tubiform bone,and there was statistically significant difference for occurrence of this imaging sign between investigative group and control group(P＜0.05).(5)In all the polyostotic fibrous dysplasia cases which involved rare sites(4 cases),the bone lesions occured in the bones on one side of the body.Conclusion:(1) Fibrous dysplasia of bone located at rare sites could display some collective CT features of fibrous dysplasia of bone(ie,cystic bone destructions, lucent area,"ground glass"-like density,calcification,sclerotic border,internal septation).(2) Body of vertebra was involved chiefly in fibrous dysplasia located at vertebra.The relative marked CT features of fibrous dysplasia in vertebra are "ground glass"-like density,calcification,sclerotic border.(3) Fibrous dysplasia of bone located at plat bone could display collective CT features of general fibrous dysplasia of bone.(4) "Ground glass"-like density is a relative marked CT feature of fibrous dysplasia located at short tubiform bone.(5) For the polyostotic fibrous dysplasia cases which involved rare sites,the bone lesions tend to be homolateral distribution.