头颅CT颅底线性参数对诊断I型Chiari畸形的辅助作用

Diagnosis of Chiari malformation type I by cranial base morphological descriptions with head CT

目的通过头颅CT重建,对小脑扁桃体下疝畸形I型(CMI)患者颅底线性和角度参数进行描述,评估其对CMI的辅助诊断作用。方法以我院神经外科在2010年1月至2013年12月期间连续收治的65例CMI患者和41例同期非CMI患者作为研究对象,测量两组在斜坡长度,McRae线,Twining线,Chamberlain线,Klaus指数,基底角,Boogard角,小脑幕角共8项指标之间的差异,并依据有显著性差异的指标,通过Logistic回归拟合建立诊断CMI的回归方程。结果本组研究表明,除Chamberlain线外,剩余7项指标两组间有显著性差异;经变量剔除,最终保留斜坡长度和小脑幕角作为变量建立数学模型,以Y=0.456为临界值,可达到最佳的敏感度(84.3%)和特异度(87.8%)。结论头颅CT可以很好地实现颅底结构测量,联合测量斜坡长度和小脑幕角可以提高CMI患者的诊断敏感性和特异性,头颅CT可以对CMI的诊断提供辅助作用。

The feasibility of using head cr as a tool in the diagnosis of Chiari malformation type I via description of cranial base structures in lines and angles is discussed. Methods Sixty-five patients diagnosed with Chiari malforrrkation type I （CMI） during January 2010 and December 2013 were enrolled as the patients group and were compared with the control group which consisted of 41 mdiologically normal patients. Eight parameters were measured on the reconstructed mid-sagittal CT images： clivus length, McRae line, Twining line, Chamberlain line, Klaus index, basal angle, Boogard angle, tentorial angle. A Logistic regression formula was calculated based on those significant differenced parameters. Results In this study, all the 8 parameters except Chamberlain line were found significantly different between the CMI group and the control group. Further analysis showed clivns length and tentorial angle may be used in the final Logistic formulation with an optimal sensitivity （84. 3% ） and specificity （87.8%）. Conclusion Head CT can describe the cranial base in detail, while murements in combination with clivus length and tentorial angle increase the diagnostic sensitivity and specificity of CMI. Head CT may be used as a tool for the diagnosis of CMI.