ChiariⅠ型畸形的诊断标准再探讨  

The Reinvestigation of Diagnostic Standard of Chiari TypeⅠ Malformation

作　　者：王梅云 戴建平 高培毅 程敬亮[2] 李树新[2] 

机构地区：[1]北京市神经外科研究所 [2]郑州大学第一附属医院放射科

出　　处：《实用放射学杂志》2005年第6期569-571,共3页Journal of Practical Radiology

基　　金：河南省自然科学基金资助项目(基金编号:0211041700)。

摘　　要：目的采用新方法再探讨ChiariⅠ型畸形的诊断标准。方法利用医用计算机图像处理软件0SIRIS,对27例小脑扁桃体下疝超过5mm的ChiariⅠ型畸形病例、25例小脑扁桃体下疝<3mm的可疑ChiariⅠ型畸形病例以及40例不伴中枢神经系统疾病的患者的头颅MRI图像分别进行颅腔和脑实质的径线与面积的测量,并对测量结果作统计学分析。所选病人均在18岁以上,MRI资料完整,不伴颅内高压、环枕融合和颅底凹陷。结果ChiariⅠ型畸形可疑组的枕底长与斜坡长的比值明显大于ChiariⅠ型畸形组(P<0.05),后脑面积与后颅窝面积的比值明显小于ChiariⅠ型畸形组(P<0.05),而这2项测量结果与对照组之间差异无显著性(P>0.05);此外,可疑组的后脑面积与大脑面积及大脑面积与幕上颅腔面积的比值与对照组和ChiariⅠ型畸形组间差异均无显著性(P>0.05)。结论ChiariⅠ型畸形以小脑扁桃体下疝超过5mm为诊断标准较为合理,下疝<3mm应视为正常。该研究结果也支持后颅窝骨发育不良导致后颅窝过度拥挤是ChiariⅠ型畸形发病机制的学说。Objective To reinvestigate the diagnostic standard of Chiari type Ⅰ malformation by the use of a new measurement method. Methods A measurement of the posterior cranial fossa structures on the mid-sagittal MRI was carried out on 27 cases of Chiari type Ⅰ malformation with tonsillar herniation of more than 5mm,25 cases of suspicious Chiari type Ⅰ malformation with tonsillar herniation of less than 3mm and 40 normal subjects without central nervous system involvement by the means of OSIRIS,a medical image processing software.The analysis of variance was used for statistical anslysis. All the patients were over 18 years old,without hydrocephalus and other skull base anomalies. Results Comparing to the Chiari type Ⅰ malformation group,there was a significantly larger basioocciput-clivus ratio and a smaller brain-skull ratio of the posterior fossa of the suspicious group(Ρ<0.05),but there was no difference between the suspicious group and the control group (Ρ>0.05). Besides,the ratio of posterior- supratentorial brain and the supratentorial brain-skull ratio of the suspicious group had no significant difference with the Chiari type Ⅰ malformation group and the control group (Ρ>0.05). Conclusion It seems that it’s reasonable to take tonsillar herniation of more than 5mm below the foramen magnum as the diagnostic standard of Chiari typeⅠmalformation,and patients with tonsillar herniation of less than 3mm should be taken as normal. The results also supported the theory that an underdeveloped occipital bone with normally developed neural structures, inducing overcrowding in the posterior cranial fossa,may play an important role in the cause of Chiari typeⅠmalformation.

关 键 词：CHIARI Ⅰ型畸形 磁共振成像 枕骨 后颅窝 颅骨测量学 

分 类 号：R742.82[医药卫生—神经病学与精神病学] R445.2[医药卫生—临床医学]