影响CT测量BMD精确性因素的探讨  

Study of Factors Influencing Accuracy of BMD CT Measurement Determination

作　　者：沈文[1] 祁吉[1] 张文波 刘亚武 雷新玮[1] 刘筠 

机构地区：[1]天津医科大学第一中心医院,300192

出　　处：《中国医学计算机成像杂志》1997年第1期42-45,共4页Chinese Computed Medical Imaging

摘　　要：目的：利用QCT技术进行实验性BMD测量。材料和方法：以不同深度的水（2cm，4cm，6cm，8cm，10cm，12cm，14cm，16cm，18cm，20cm，22cm，24cm，）模拟不同的软组织厚度；以不同浓度的磷酸氢二钾溶液（160mg/ml，180mg/m，1200mg／ml）模拟不同的骨矿物质含量，同一样本在不同深度的水内置于同样的位置，又不同样本在相同深度的水内置于同样的位置，均分别重复扫描10次，检测样本密度值，并行统计处理。结果：随着水深度增加，所测各样本的BMD值均降低；不同浓度样本置于相同深度时，不影响测量结果的精确性。通过对测量结果进行统计学处理，得出校正公式为：（BMD）真实值=（BMD）测量值-1.140＋0．973H－0．0158H2。结论：样本浓度对BMD测量值影响不大，软组织厚度对测量值有影响，软组织越厚，BMD测量值比实际值越低。A Phantom experiment was performed in order tD determine the accuracy of QCT in determination of the BMD. Materials and methods: The defferent depths of water were used to mimic the different thickness of the soft tissue, and the varied concentrations of the K_2HPO_4 solution were used to mimic the varied bony mineral densities in the experiment. Results: The result showed that the concentrations of the K_2HPO_4 solution(different value of the BMD)didn't have significant influence to the accuracy of the detected BMD, but the depths of water (different thickness of the soft tissue) shoud let the results deviate from the actual value. Depending on the result of eaperiment, a formula for correcting the result of the QCT was obtained, such as(BMD)o =(BMD) i - 1.140 + 0. 973H - 0. 0158H^2. Conclusion: The concentration of the sample did not have significant influence to the BMD value. Thickness of the soft tissue have influence to the BMD value. Thicker of the soft tissue, lower of the BMD value than the artual value.

关 键 词：骨矿盐密度 骨密度 CT BMD X线诊断 

分 类 号：R814[医药卫生—影像医学与核医学] R816.8[医药卫生—放射医学]