儿童寰枢关节旋转不稳相关结构的MRI研究

Structures related to atlanto-axial rotation instability in children： an MRI study

目的观察儿童功能位寰枢关节旋转不稳时关节韧带及其他软组织的MRI表现。方法对2013年1月至2014年3月治疗的50例儿童寰枢关节旋转移位患者资料进行回顾性分析，并设为观察组，选取同时期健康体检的50例儿童作为正常组。两组均采取同样的设备仪器及MRI诊断方法进行临床诊断，分析寰枢关节周围韧带及其他软组织的MRI影像表现及特征。结果观察组50例患儿齿状突两侧间隙不对称，其中左侧偏移32例，右侧偏移18例。采用MRI PDWI成像序列对韧带结构的诊断正确率比其他序列（T1WI、T2WI、SPAIR）高，差异均有统计学意义（P〈0．05）。所有儿童的寰枢关节采用不同MRI序列对韧带及其他软组织显示，Ⅰ度损伤：观察组50例，正常组4例；Ⅱ度损伤：观察组12例，正常组0例，MRI对两组Ⅰ、Ⅱ度损伤的诊断率比较差异均有统计学意义（P〈0．05）。结论MRI能明确显示由于横韧带、翼状韧带及周围软组织病变造成的寰枢关节旋转移位，MRI对于诊断儿童寰枢关节旋转移位、特别是外伤后横韧带撕裂引起的旋转移位具有明确的诊断价值。

Objective To observe the MRI imaging manifestations of the ligaments and soft tissues around the atlanto-axial joint in children with atlanto-axial rotation instability. Methods Assigned into observation group were 50 children with atlantoaxial rotatory displacement who had been treated in our hospital from January 2013 to March 2014. Another 50 healthy children were chosen as a control group who underwent health check-ups during the same period in our hospital. Both groups received MRI examinations of the ligaments and soft tissues around the atlantoaxial joint using the same equipment and methods. MRI manifestations and characteristics of the ligaments and soft tissues around the atlantoaxial joint were analyzed and compared between the 2 groups. Results In the observation group, odontoid gap asymmetry appeared on both sides, with left shift in 32 cases and right shift in 18 cases. The MRI imaging PDWI sequence showed a significant better di- agnostic sensitivity than the other sequences （T1WI, T2WI and SPAIR） （ P 〈 0.05）. The MRI examinations on all the children with different sequences found 50 cases of degree Ⅰ lesion in the observation group and 4- cases of degree Ⅰ lesion in the control group, and 12 cases of degree Ⅱ lesion in the observation group and none degree Ⅱ lesion in the control group, showing a significant difference between the 2 groups regarding the diagnostic sensitivity of lesions of degrees Ⅰ and Ⅱ （ P 〈 0. 05 ） . Conclusions MRI can clearly show the rotation displacement of atlanto-axial joint associated with transverse ligament, alar ligament and lesions of the surrounding soft tissues. MRI has a definite diagnostic value for atlanto-axial rotation displacements in children, especially those caused by transverse ligament tear after trauma.