Spinal Osteoblastoma:Clinical,imaging Features With Pathological Correlation

[Objective]1.To study the CT,MRI and PET-CT findings of spinal osteoblastomas,2.To study the correlation between the imaging features and the stage of the tumor.In order to improve the understanding of spinal osteoblastomas,and to provide an important reference for the preoperative diagnosis and assessment.?Methords?1.The imaging and clinical data of 16 cases of spinal osteoblastoma confirmed by surgery and pathology were analyzed retrospectively.2.All cases were staged by clinical,imaging and pathology,and analyzed the correlation between the different stages of tumor and imaging features.[Results]The incidence ages of 11 cases were from 10 to 29 years old,5 cases were from 30 to 51 years old;male 11 cases,female 5 cases;8 cases of thoracic,4 cases of cervical vertebrae,4 cases of lumbar spine;13 cases were originated from the spinal accessory,and 3 from the vertebral body,1 case of vertebral disease;6 cases presented as expansive bone destruction,and 10 as osteolytic bone destruction;13 cases were benign,and 3 were invasive;1 case of secondary aneurysmal bone cyst,1 case of secondary pathological fracture;16 cases of lesions with diameter of 38mm,1 case of less than 20mm,15 cases of more than 20mm.CT showed:calcification or ossification could be found in all lesions;15 cases were accompanied with soft tissue mass;spinal canal involvement was foumd in 13 cases.6 cases of expansive bone destruction,one sclerosis edge continuous;in the case of osteolytic bone destruction in 10 cases,there was no clear sclerotic edge,bone separation in the 3 cases.3 cases of invasive cervical lesions involving paravertebral soft tissue and ribs.MRI showed:13 cases showed iso-or hypo-intensity on T1WI and iso-or hyper-intensity on T2WI,seen around the uneven low signal ring in some cases;13 cases with soft tissue mass and spinal involvement,7 cases showed multiple cysts,7 cases of spinal cord were compressed;13 cases showed heterogenous enhancement post contrastly,and the surrounding soft tissue was enhanced obviously.Calcification,ossification and cystic change were not enhanced.PET-CT in 5 cases depicted nodular or lobulated high radioactive concentration,and increased standard uptake values as well.13 cases of benign tumor Enneking stage II stage in 6 cases,III stage in 7 cases,all of the 3 cases of invasive tumors were III stage.CT showed:6 cases of II stage tumor showed expansive bone destruction,the cortical bone was continuous,and the tumor was confined to the intracompartment;10 cases of III stage tumor showed osteolytic bone destruction,the cortical bone was interrupted,and the tumor invaded to the extracompartment.MRI showed:4 cases of II stage tumor clear boundary,homogeneous signal,surrounding linear low signal ring,enhancement scanning showed homogeneous enhancement;9 cases of stage III tumor is large,uneven signal,bump to the paravertebral and epidural extension,markedly inhomogeneous enhancement.PET-CT showed:2 cases of stage ? tumor was nodular high radioactive concentration,and increased standard uptake values as well;3 cases of stage ? tumors were lobulated high radioactive concentration,and increased standard uptake values as well.?Conclusion?1.Spinal osteoblastoma tends to occur in adolescents and young patients,more males than females,tumor diameter more than 2cm,with the characteristics of partly invasive and typical imaging:the spinal accessory area was swelling,osteolytic bone was destructive accompanied by soft tissue mass,together with speckled or tubercular calcification or ossification within it,;T1WI signal was shown as iso-intensity and hypo-intensity,and that of T2WI was iso-intensity and hyper-intensity,partial and thin unequal low signal rings in some lesions;there was heterogeneous enhancement on enhanced scans;PET-CT enhancement scanning revealed that the tumors are nodular or lobulated high radioactive concentration,with increased standard uptake value.2.The correlation between the imaging features and the stage of tumor of the spine is closely related,the ? stage of the tumor was characterized by the expansion of bone destruction,the cortical bone was continuous,and the tumor was confined to the intracompartment;stage ? tumors showed osteolytic bone destruction and tumor invasion to the extracompartment.3.The comprehensive use of CT,MRI and PET-CT examination play an essential role in the qualitative diagnosis of tumor,tumor stage,surgical treatment and recurrence,etc.