ChiariⅠ畸形颅腔(脑)MR测量研究

目的 :运用MRI对ChiariⅠ畸形病人进行颅腔 (脑 )形态学测量 ,探讨ChiariⅠ畸形的发病机制。方法 :选择MRI资料完整 ,不伴脑积水、肿瘤或外伤所致小脑扁桃体下疝者共 114例 ,选择经MRI检查不伴中枢神经系统疾病者 10 0例作为对照组在颅脑或颈椎 (旁 )正中矢状面SETlWI上对ChiariⅠ畸形病人和对照组的颅腔(脑 )形态结构进行测量。测量结果用t检验 (双侧 )进行统计分析。结果 :枕大孔径、第四脑室顶水平距、后颅宽、后枕角、(全颅宽×全颅深 )、(后脑宽×后脑长 )、(大脑宽×大脑深 )、{(大脑宽×大脑深 ) /[(全颅宽×全颅深 ) -(后颅宽×后颅深 ) ] }在两组间无显著性差异 ;扁桃体垂直径、天幕角、后颅角、颅底角、[(后脑宽×后脑长 ) /(后颅宽×后颅深 ) ]在ChiariⅠ畸形组明显大于对照组 (P <0 0 5 ) ;第四脑室顶高距、斜坡长、后枕长、后颅长、后颅深、斜坡角、(后颅宽×后颅深 )在ChiariⅠ畸形组明显小于对照组 (P <0 0 5 )。结论 :ChiariⅠ畸形病人颅后窝容积明显小于对照组 ,而后组脑神经结构在两组间无显著差异 ,说明ChiariⅠ畸形的病变是在后颅的骨性结构 ,而非神经结构 ,ChiariⅠ畸形的发病原因是发育正常的后脑位于发育狭小的后颅颅腔内 ,颅后窝过度拥挤 ,导致小脑扁桃体下疝形成

MR MORPHOMETRIC STUDY OF CRANIAL CAVITY (BRAIN) IN CHIARI I MALFORMATION

Objective:MRI was used to measure the cranial and neural structure in patients with Chiari I malformation in order to find out the pathogenesis of Chiari I malformaion. Methods:The cranial and neural structure were measured on midsagittal MR imaging in 114 patients and in 100 normal people. t-test was used for statistical analysis.Results:Compared to the control group,there was a significantly smaller posterior cranial fossa in patients.There was no significant difference in the posterior brain between the two groups. Conclusion:These data support accumulating evidence that Chiari I malformation is a disorder of the para-axial mesoderm that is characterized by underdevelopment of the posterior cranial fossa and overcrowding of the normally developed hindbrain.