两种DXA骨密度体模比较研究

Comparison research of two kinds of inspection phantoms

研究比较国产QC-2型腰椎骨密度体模（以下称QC-2体模）和欧洲脊椎骨密度体模（以下称ESP体模）在双能X射线全身骨密度仪（以下称DXA）检定中的差异性。用DXA仪器对这两种体模分别进行检测,对测量结果进行比较分析。（1）QC-2型体模和ESP型体分别被仪器进行测量时,仪器测量的BMD同两个体模的BMD相比,误差分别在-15.1%-11.5%和-16.1%-12.5%之间;而且,两个体模的各自标称值与相应的仪器测量值之间,分别都有非常好的线性关系,r〉0.99。（2）用回归方程进行校正后,仪器值（BMD）与两个体模的各自的标称值之间的误差分别在-3.8%-4.4%和在-3.8%-4.4%之间。用成对样本均数比较方法,对校正结果进行统计分析,经配对t检验,二者结果没有显著差异（P〉0.05）。表明这两种腰椎骨密度体模都能用于双能X射线全身骨密度仪（DXA）的检定。

Differences between domestic QC-type 2 spine density phantom （hereinafter referred to as the QC-2 phantom） and the European spine density phantom （hereinafter referred to as the ESP phantom） were studied when they were used to verify dual energy X-ray whole body bone mineral density instrument （hereinafter referred to as the DXA）. Two phantoms mentioned above were tested with DXA instrument respectively, and the measuremental results were comparatively analyzed. As the results, when the phantoms were measured with the instrument respectively, the errors between the instrument measuring BMD and that of QC-2 Phantom and ESP phantom were from -15.1% to 11.5% and from -16.1% to 12.5% respectively. The nominal value of each phantom has a very good linear correlation （r〉0.99） with the corresponding instrument value. The errors between the instrument value （BMD） and the nominal value of each phantom were from -3.8% to 4.4% from the results of regression analyses. The result of statistical analyses carried out with the comparing paired sample mean method, i.e., ＂t＂ test, there were no significant differences between the results of two phantoms （P〉0.05）. Thus, these two spine density phantoms can be used to verify the dual energy X-ray whole body bone mineral density instrument.