骨密度定量CT测量用固体标准件的研究

Study of solid calibration phantom for bone mineral density CT measurement

目的报告一种自制骨矿密度ＣＴ测量固体标准件。方法使用聚乙二醇塑料和骨基质加工成固体标准件，其两部分Ｘ线衰减特性分别相当于水和骨组织，体积为３０．０ｃｍ×９．０ｃｍ×２．５ｃｍ，重量为０．７ｋｇ。对１２个椎骨标本灰化进行标准性测试。结果骨密度定量ＣＴ（ＱＣＴ）测量结果和灰化标本灰重值相比准确性为８．６％，二者间具有非常显著相关性（ｒ＝０．９１，Ｐ＜０．００１），标准件的精确性为１．１％和０．１％。结论本组固体标准件质量可靠，为国内ＱＣＴ骨密度测量提供了一种新的更准确。

Purpose To introduce a selfmade solid calibration phantom for bone mineral density(BMD)measurement with quantitative CT(QCT). Methods The solid phantom was made of polyethylenebased plastics and bone matrix equivalent. The xray attenuation characteristics was the same as water and bone tissue on its two parts: the volume was 30.0cm×9.0cm×2.5cm, and the weight 0.7 kg .Precise measurement of 12 vertebral specimens was done. Results Accuracy of the phantom was by comparing the results of QCT measurement and weight of the specimens. QCT and bone ash weight had high correlation of statistical significance with r=0.91, P<0.001. Conclusion The results showed that the solid calibration phantom is reliable, with small size, lower cost and ease of use , suitable for QCT of BMD measurement in our country.