【摘要】 目的　研究正常小脑扁桃体下缘的形态和位置 ,探讨不同性别和年龄组的正常值范围 ,为诊断Chiari畸形Ⅰ型 (chiarimalformationtypeⅠ ,CMⅠ )提供参考标准 ,并探讨小脑扁桃体发育规律及临床和病理意义。资料与方法　测量 178例正常人MRI矢状位片上小脑扁桃体下缘至枕骨大孔平面的距离 (h)。对不同性别、年龄与小脑扁桃体位置的关系进行相关分析。从 0岁起每 10年划分为一个年龄组 ,共 8个年龄组 ,比较每两个年龄组之间h值的差别。结果　本组小脑扁桃体下缘均呈圆钝形。性别与h值没有相关性 ;年龄有相关性 ,随着年龄的增加 ,h值有增大的趋势。得回归方程为h =1.0 91+0 .2 72age。对方程进行方差分析 ,F =5 .2 34,P <0 .0 0 1,认为方程有统计学意义。本组h值均值为 1.9± 1.8mm ,各组数据之间有显著差别。对每两个年龄组之间进行检验 ,第 8组和第 1～ 5组之间有显著差别 (P <0 .0 5 )。其余各组之间无显著差别 (P >0 .0 5 )。 30岁以前小脑扁桃体下缘在枕骨大孔平面下 3mm ;30～ 6 0岁在其下 2mm ;6 0岁以后 1mm ,为正常值范围的下限 ,超过此范围 ,应视为异常。结论　小脑扁桃体的形态对CMⅠ的诊断有价值。正常形态均为圆钝形。性别与小脑扁桃体位置无关 ,年龄与其有关。研究与小脑扁桃体位置有关的疾病 ,更多还原

【Abstract】 Objective To establish a diagnostic criteria of Chiari malformation type Ⅰ (CM Ⅰ) for Chinese, by analysing the position and shape of the cerebellar tonsils in the normal population with different gender and ages on MRI. Materials and Methods The distance (h value) between the cerebellar tonsils and foramen magnum was measured on sagittal T 1WI in 178 patients, who did not have the diseases affecting tonsils position, and aged from nine month to 81 years. All patients were grouped into 8 groups according to age at 10 years apart. The h values among the groups were compared, and the relationship of the position of the tonsils, gender and ages was subsequently analyzed.Results The normal tonsils appeared round in this series. The regressive equation was drawn as h=1.091+0.272 age. The equation was statistically analyzed by the square of the variation (F=5.234, P<0.001), which was statistically significant. The mean h value was 1.9±1.8mm (mean±standard). There was not significant relationship between the h value and gender (P>0.05), but significant relationship between the h value and ages (P<0.01). With the increase of ageing, the h value was greater. The group 8 was significantly different from the group 1 to 5 (P<0.05), but no difference between the remaining groups (P>0.05). The h value was 3mm under 30 years old, 2mm within 30～60 years, 1mm beyond 60 years. The h value out of the range based on the age was considered abnormal.Conclusion The change of tonsil shapes contributes to the diagnosis of CMⅠdue to the round shape of the normal tonsil. The age is closely relate to h value, whereas the sex is not. The diagnosis of CMⅠ should be comprehensively made by clinical manifestations together with imaging features. The h value of greater than 5mm indicates CMⅠ, and CMⅠ should be suspicious within 1 to 5mm.更多还原