正常人群骨矿物含量的定量CT测量和研究

Quantitative Computed Tomographic Measurement and Study of Bone Mineral Contents in Normal Individuals

目的：用自制固体标准体模对正常人群骨密度进行定量ＣＴ测量和研究。方法：聚乙二醇塑料内添加氯化镁、碳酸钙和羟基磷灰石制成Ｘ线衰减系数分别相当于水和骨的定量ＣＴ用固体标准体模，并进行精确性和准确性检测。并对３２３例２０～６９岁正常人腰椎做定量ＣＴ测量。结果结论：自制固体标准体模精确性为１．１％和０．１％，灰化检验准确性为８．６％。男性骨密度与年龄呈直线相关，ｒ＝－０．６６，Ｐ＜０．０５，女性骨密度呈立方回归关系，ｒ＝－０．７０，Ｐ＜０．０５。两性腰椎松质骨密度均在２０－２９岁达到高峰值，以后逐年下降，４０岁以后下降明显，女性更为突出（Ｐ＜０．００１）。同一年龄组间存在骨密度个体差异，且随年龄增大而增大。

Objective:BMD was messured by quantitative CT in normal individuals using solidified standardized phantom made by ourselves. methods:The phantom for QCT was made of polyethleneglycol plastic mixed with magnesium oxide,cathium carbonate and hydroxylapatite which x ray attenuation characteristics equivalent to those of water and bone respectively.And its accuracy and precision was tested.We messured lumbs of 320 normal individuals ages from 20 to 69 by QCT.Results and Conclusion:The accuracy and precision were 1.1% and 0.1%.The precision tested by ash bone was 8.6%.Corralation with age were linear regression in male (r=-0.66,P<0.05) and cubic regression in female (r=-0.70,P<0.05).The peak value of both sexual groop of BMD was in range of age 20￣29.BMD of both sexual groop were obviouslly decrease every years and more protruding in female (P<0.001).BMD was deferent individually in each range of ages and it decreased while ages increasing.