CT研究寰椎正常发育与变异

CT study on the normal development and variation of the atlas

背景:寰椎发育演变过程复杂,研究报道较少,CT成像能很好地显示寰椎解剖。明确寰椎正常发育过程、解剖结构、发育变异与畸形有着重要的临床意义。目的:利用CT影像解剖展示寰椎正常发育与变异。方法:收集厦门市儿童医院、厦门大学附属中山医院医学影像存档与通信系统内0-14岁患者的寰椎CT资料,最终纳入732例患者的CT资料,观察寰椎前弓及双侧椎弓骨化中心,椎弓、前正中、后正中骺板、横韧带结节及寰椎发育变异或畸形。结果与结论:(1)732例患者中,CT图像显示寰椎正常发育679例(占92.76%);发育畸形或变异53例(占7.24%),其中骨环不完整27例,出现副骨化中心及副骺板23例,寰枕关节畸形3例;(2)寰椎骨化中心3个,包括椎弓侧块2个和前弓1个,2个椎弓出现于胎儿期,1个前弓出现于生后2 d-2岁,中位年龄为6个月,四分位距为4-11个月;(3)寰椎骺板4个,包括椎弓骺板2个、前正中骺板1个、后正中骺板1个,2个椎弓骺板闭合中位年龄是6.2岁,年龄四分位距为4.5-7岁;前正中骺板出现率为37.43%,闭合年龄中位数为4.8岁,年龄四分位距为2.8-6.0岁;后正中骺板闭合年龄中位数为2.8岁,年龄四分位距为2-3.8岁;(4)横韧带结节出现的中位年龄为9岁,年龄四分位距为5.5-10岁;(5)结果显示,寰椎骨化中心出现与骺板闭合时间存在相对特定的年龄区间,寰椎发育变异或畸形以寰椎骨环不完整、副骨化中心及副骺线多见,CT影像观察寰椎发育或畸形清楚、准确,具有明显优势。

BACKGROUND:The development and evolution of atlas are complex,and there are a few research reports.CT imaging can clearly show the atlas.It is of great clinical significance to clarify the normal development process,anatomical structure,variation and malformation of atlas.OBJECTIVE:To show the normal development and variation of atlas using CT imaging.METHODS:The atlas CT data of patients aged 0-14 years in the picture archiving and communication system of Xiamen Children s Hospital and Zhongshan Hos pital of Xiamen Unive rsity were collected,and the CT data of 732 patients were finally included.The observation items included:The ossification centers of ante rior arch and ve rtebral arch,the epiphyseal plates of ve rtebral arch,ante rior and poste rior median,the tubercle of transverse ligament and the va riation and deformity of atlas.RESULTS AND CONCLUSION:(1) Among 732 cases of atlas,CT images exhibited that 679(92.76%) had normal development,53(7.24%) variation or deformity.Among them,there were 27 cases of incomplete bone ring,23 cases of accessory ossification center and accessory epiphyseal plate,and 3 cases of atlantooccipital joint deformity.(2) There were three ossification cente rs,including two lateral ve rtebral arches and one anterior arch.The bilateral ossification cente rs of two vertebral arches appeared in the fetal period;the ante rior arch ossification center of one vertebral arch appeared from 2 days to 2 years after birth,the median age with 6 months and the interqua rtile-range with 4-11 months.(3) There were four epiphyseal plates,including two ve rtebral arch epiphyseal plates,one anterior median epiphyseal plate,and one posterior median epiphyseal plate.The two epiphyseal closures of vertebral arch were at the median age of6.2 years,interquartile-range of 4.5-7.0.The occurrence rate of anterior median epiphyseal plate was 37.43%.That of anterior median was at the median age of 4.8 years,interqua rtile-range of 2.8-6.0 years and the posterior median at 2.8 years,interqua rtile-range of 2-3.8 years.(4) The appearance of transverse ligament nodules was at the median age of 9 years,interquartile-range of 5.5-10.(5) These findings have concluded that there is a specific age range between the appearance of ossification center and the closing of epiphyseal plate.The variations or deformities of atlas are mainly the incomplete bone ring,accessory ossification center or epiphyseal line.CT image showing the development or deformity of atlas is clear and accurate,which has many advantages.