正常人寰枢关节间隙的CT研究

The investigation of the atlantoaxial joint space of normal individuals by CT

目的 :研究正常人寰枢关节CT图像关节间隙大小及功能位置间隙变化情况 ,并对相关因素进行探讨。方法 :12 0例正常人行中立位CT扫描 ,6 6例行冠状矢状位重建 ,5 6例行头颅左、右旋各 15～ 2 5°扫描 ,30例行侧曲及屈、伸位扫描 ,5 6例均摄取中立位及左、右旋转位 15～ 2 5°X线片。测量CT片寰齿间隙值 ,观察功能位间隙变化。结果 :寰齿前间隙(ADI)值在不同年龄阶段存在差异。齿突与环椎侧块间隙 (LADS) ,青年儿童组两侧不对称比例及程度高于成人 ,间隙不对称者寰枢椎发育异常所占比例较高。发现寰枕间存在相对旋转者 2 8例。头颅左、右旋转位 ,42 .86 %受检者旋转同侧LADS变窄 ,5 7.14%无明显改变与平片结果不同。结论 :CT扫描对于显示寰枢区结构有X线平片无可比拟的优越性 ,X线平片旋转位间隙变化不同于CT扫描。

Objective:To investigate the atlantoaxial joint space of normal individuals in neutral and functional position using CT.Some related factors were discussed.Methods:120 normal subjects were examined in neutral position with CT,66 cases with sagittal and coronal reconstuctions.56 cases were examined with the head rotating to the right and left respectively.30 of 56 cases were evaluated with the head in tilt and flexion-extension position.56 cases radiographed in neural and right/left position at the same time.Then atlanto-dental interval(ADI) and lateral atlanto-dental space(LADS) were measured and changes of them in functional positions were analyzed.Results:There were differences in ADI of different age groups.As to LADS,the percentage and extent of the space asymmetry of the younger were higher than that of the adult;the percentage of the displasia in atlantoaxial vertebra was higher in the asymmetrical cases.The rotation in the occipital-atlanto joint were found in 28 cases.Contrary to the results of the plain X-ray,42.86% cases with the scans in rotatory position have the trends that the LADS on the same side turned narrow,57.14% cases appears to have no change.Conclusion:CT has considerable value for the manifestation of the atlantoaxial joint,it's better than plain X-ray in many aspects.The criteria of plain X-ray are inadequate for the diagnosis of the diseases using CT,new criteria should be put forward.