游离齿突小骨多层螺旋CT表现特点和诊断

The MSCT Features of Os Odontoideum

目的探讨游离齿突小骨的多层螺旋CT(MSCT)影像学表现特征,以提高对其诊断和鉴别诊断水平。方法搜集游离齿突小骨12例患者资料,均无家族史。12例均行MSCT轴位平扫,并行最大密度投影(MIP)、多平面重组(MPR)、容积再现(VR)等后处理。结果 MSCT像上齿状突游离小骨有以下影像特点:C2齿突基底部前上方均有发育不良的小骨,与枢椎齿状突体基底部有分离,小骨周边有薄层完整骨皮质。游离齿突小骨均有位置异常,多伴有颅颈部和C1/2不稳应引起重视。椎管狭窄率为91.7%,并发现有脊髓明显受压。结论 MSCT显示C2齿突基底部前上方有发育不良和移位的小骨与枢椎齿状突体基底部分离,此为游离齿突小骨特异性影像学表现。

Objective To explore the MSCT characteristics of Os Odontoideum, so as to improve diagnosis. Methods A total of 12 cases of Os Odontoideum with no family history were collected. MSCT were performed in those 12 cases with post processing with MIP, MPR, and VR. Results The following MSCT features were found in Os Odontoideum： The dysplastic small bone was found anterior to basal parts of C2 , separated from dens of C2 vertebra. The small bone was sur- rounded with complete bone cortex. Os Odontoideum had an abnormal position in all of the cases. Most of Patients had cra- nial cervical and Cln instability while spinal stenosis was found in 91.7%. Conclusion Correct diagnosis of Os Odontoi- deum can be made when a hypoplastic small bone separated from the basal part of C2. CT is helpful in guiding surgical treatment of Os Odontoideum.