斜坡的磁共振成像测量研究

目的　用MRI测量正常国人和Chiari畸形患者的斜坡长度和倾斜角 ,以探讨其正常值范围及其发育规律。材料与方法　在颅脑正中矢状面SET1WI上测量了 3 17例正常人、2 9例Chiari畸形和 13例可疑患者的斜坡长度和倾斜角。正常人按性别和年龄分为 16组 ,每组 2 0例 ( 70岁以上女性组仅 17例 )。MRI应用 1.0T超导MR系统 ,并以t检验作统计分析。结果　正常斜坡长度和倾斜角随性别、年龄不同而有所差异。男性斜坡长于女性 (P <0 .0 5 ) ,且于 2 0岁前随年龄而增长 ,之后基本稳定 ;其倾斜角于 2 0岁前随年龄而增大 ,于 3 0岁前后基本稳定 ,两性差异无显著性 (P >0 .0 5 )。Chiari畸形及可疑患者斜坡长度短于正常人 (P <0 .0 5 ) ,其倾斜角也小于正常人 (P <0 .0 5 )。结论　斜坡长度和倾斜角有一定的正常范围和发育规律 ;斜坡短于 41mm为发育过短 ,倾斜角小于 5 0°为斜坡发育过平。Chiari畸形以小脑扁桃体下端位置低于颅基线 3mm作为诊断标准为宜 ,其常伴斜坡短平。

A Clinical Quantitative Study of Clivus in Chinese Individuals with MRI

Objective To determine the normal range of the clival length (CL)and the clival oblique angle (COA) in normal Chinese individuals and patients with Chiari malformation by measuring with MRI.Materials and Methods CL and COA on midsagittal MRI were measured in 317 normal subjects and in 42 patients with Chiari malformation. The normal subjects were divided into 16 groups according to the sex and age, 20 subjects each group with the exception of female group of age over 70 (only 17 subjects). MRI data were obtained with a 1.0T MR scanner, and t-test was used as statistical significance test.Results The CL of male Chinese was longer than that of female Chinese, the difference was of statistical significance (P＜0.05), and it was increasing with age before around 20 years old, then remained stable. The COA was increasing with age before 20 years old and became slightly small in one's third decade, then grew steadily. No significant difference in COA was found between male and female (P＞0.05). The differences in both COA and CL were statistically significant between the normal group and group of patients (P＜0.05).Conclusion The CL and COA in Chinese subjects carry their normal ranges and show a certain regular developmental pattern. Developmental abnormalities should be considered when CL is less than 41mm or COA is less than 50° in a Chinese adult. When the lower 0 border of tonsil is located 3mm below the cranial baseline Chiari malformation may be diagnosed.