Imaging Diagnosis And Comparative Study Of Secondary Aneurysmal Bone Cyst

Purpose:1.To analyze the imaging diagnosis of X-ray plain,CT and MRI in secondary aneurysmal bone cyst.2.To evaluate the diagnostic value of three imaging combination(X-ray plain+CT,X-ray plain+MRI and X-ray plain+CT+MRI) in secondary aneurysmal bone cyst.3.To analyze the differential diagnosis in primary aneurysmal bone cyst and secondary aneurysmal bone cyst derived from giant cell tumor.Materials and methods:1.Materials:We collected 48 cases of secondary aneurysmal bone cyst in Foshan Hospital of Traditional Chinese Medicine and Nan Fang Hospital.There were 32 male and 16 female.The ages of patients ranged from 5 to 70 years,average age was 28.4 years. All patients imaged with X-ray plain.Among the 48 cases,19 were imaged with CT scanning,15 with MR imaging,14 with both CT scanning and MR imaging.All cases had been confirmed by pathology,the primary lesion were giant cell tumor of hone(n=34),osteofibrous dysplasia(n=8),chondroblastoma(n=2),osteoblastoma (n=1),nonossifying fibroma(n=1),chondromyxoid fibroma(n=1) and fibrohistiocytoma(n=1).We Collected 49 cases of primary aneurysmal bone cyst in Foshan Hospital of Traditional Chinese Medicine and Nan Fang Hospital.There were 35 male and 14 female.The ages of patients ranged from 6 to 61 years,average age was 20.1 years, The ages of 33 cases were under 20 years.2.methods:(1) 48 patients of secondary aneurysmal bone cyst were examined by lateral and posterior-anterior conventional radiography.(2) Applied Philips PICKER IQ PREMIER and 16—slice spiral CT(Mx8000IDT) to scan 33 cases.Before 2003, applied Philips PICKER IQ PREMIER to scan with slice thickness at 5mm and slice gap at 5mm in the lesions.After 2004,applied 16—slice spiral CT to scan with collimating apparatus 16X1.5mm,pitch 0.588,reconstructive matrix 512×512 and reconstructive interval 1.0mm,applied MPR to re-establish transverse section, coronal plane and sagittal plane.(3) Applied Philips HITACHI 0.3T MRI of permanent magnet and Siemens Avanto 1.5T MRI of superconducting magnet to scan 29 cases.Before 2006,applied HITACHI 0.3T MRI to scan,all patients underwent conventional spin echo(SE) sequence and fast spin echo(FSE) sequence,The parameter of MR scan:T₁WI(TR/TE 620ms/20ms),T₂WI(TR/TE 4000ms/117ms),slice thickness at 5mm and slice gap at 6mm in the lesions.After 2007,applied Siemens Avanto 1.5T MRI to scan,all patients underwent conventional spin echo(SE) sequence and fast spin echo(FSE) sequence,short time inversion recovery(STIR) sequence was applied in some patients.The parameter of MR scan: T₁WI(TR/TE 512～700ms/11～12ms),T₂WI(TR/TE 3600～6500ms/76～120ms),STIR(TR/TE 3100～5000/38～78ms).The lesions scanned with slice thickness at 3～6mm,slice gap at 0.3～0.6mm,FOV 150mm×384mm～289mm×384mm,reconstructive matrix 126×512～270×512.All patients scanned with MRI were performed Gd-DTPA to obtain T₁WI enhancement imaging.3.imaging analysis:Analyze the X-ray plain,CT and MRI in secondary aneurysmal bone cyst(1) Analyze imaging display and feature of primary and secondary lesions in secondary aneurysmal bone cyst.(2) Analyze imaging display and feature in secondary aneurysmal bone cyst derived from giant cell tumor.(3) All patients were separated three groups:X-ray plain+CT,X-ray plain+MRI and X-ray plain+CT+MRI, evaluate exact diagnosis of respective group in secondary aneurysmal bone cyst and secondary aneurysmal bone cyst derived from giant cell tumor by single blind method.(4) We collected 49 cases of primary aneurysmal bone cyst and 34 cases of secondary aneurysmal bone cyst derived from giant cell tumor.Applied SPSS13.0 to analyze the feature of clinical information,X-ray plain and MRI by chi-square test, analyze the differential diagnosis in primary and aneurysmal bone cyst secondary aneurysmal bone cyst derived from giant cell tumor.Results:1.In 48 cases of secondary aneurysmal bone cyst,36 cases occurred at long bone,there are 5 cases at calcaneal bone,4 cases at whirbone,1 case at pubic bone,1 case at flank bone and 1 case at astragaloid bone.In 34 cases of secondary aneurysmal bone cyst derived from giant cell tumor,23 cases occurred at long bone,there are 5 cases at calcaneal bone,3 cases at whirbone,1 case at pubic bone,1 case at flank bone and 1 case at astragaloid bone.All patients of secondary aneurysmal bone cyst were separated three types:general type(primary and secondary composition were resemblance),most primary type(primary composition exceed 80%) and most secondary type(secondary composition exceed 80%).On X-ray plain and CT,the secondary aneurysmal bone cysts presented eccentric cystoid destruction of bone,with different dilatation,cortical bones were thinningz and segmented,with different sclerotic border and septation in the lesions.Pathological fracture can be seen in some cases.The feature of primary lesion in secondary aneurysmal bone cyst were homoplastic to primary disease.On MRI,secondary aneurysmal bone cysts presented different dilatation,cortical bones were thinningz and segmented.On MRI T₁WI and T₂WI,we can see the low signal ring around diseased region,the septation which have low signals both on the T₁WI and T₂WI can be seen.The diseased region bulk was full of fluid which has miscellaneous signals,it can be seen low,moderate or high signals on T₁WI and high signals on T₂WI.On enhancement scanning,the ring of the diseased region and septation in the diseased region distinctly enhanced.The cystis composition can not be seen enhanced.The feature of primary lesion in secondary aneurysmal bone cyst was homoplastic to primary disease,too.2.From statistical analysis,on diagnosis of secondary aneurysmal bone cyst, X-ray plain+CT and X-ray plain+MRI,X-ray plain+CT and X-ray plain+CT+MRI were evident difference,X-ray plain+MRI and X-ray plain+CT+MRI were no evident difference.3.From statistical analysis,on differential diagnosis of primary aneurysmal bone cyst and secondary aneurysmal bone cyst derived from giant cell tumor,age of onset, diseased region and solid composition were evident difference.Breakthrough cortical bone was no evident difference,but P of chi-square test was approximation to test criterion.Pathological fracture,fluid-fluid plane,hemosiderin and segmented change were no evident difference.Conclusion:1.Age of onset and diseased region of secondary aneurysmal bone cyst were closely relation to primary disease.CT and MRI can display the feature of primary and secondary composition in secondary aneurysmal bone cyst.MRI can display the pathological feature.2.Diagnostic exact rate of X-ray plain+MRI and X-ray plain+CT+MRI were markedly high to X-ray plain+CT,diagnostic exact rate of X-ray plain+MRI and X-ray plain+CT+MRI were no evident difference.We should use X-ray plain+MRI first.We should use X-ray plain+CT+MRI when the diagnosis is difficult.3.The patients of secondary aneurysmal bone cyst were separated three types: general type(primary and secondary composition are resemblance),most primary type(primary composition exceed 80%) and most secondary type(secondary composition exceed 80%). 4.To differential diagnosis of primary aneurysmal bone cyst and secondary aneurysmal bone cyst derived from giant cell tumor,age of onset,diseased region and solid composition were significant evidence.Breakthrough cortical bone was no evident difference,but P of chi-square test was approximation to test criterion, incorporate pathological feature,breakthrough cortical bone was significant evidence,too.Incorporate literature and our patients,hemosiderin was general evidence.Pathological fracture,fluid-fluid plane and segmented change were no evident effect of differential diagnosis.