Ilich J Z, Hsieh L C, Tzagournis M A, Wright J K, Saracoglu M, Barden H S, Matkovic V
Department of Physical Medicine, Ohio State University, Columbus 43210.
Bone. 1994 Mar-Apr;15(2):187-91. doi: 10.1016/8756-3282(94)90706-4.
We compared single photon absorptiometry (SPA) to dual x-ray absorptiometry (DXA) for determination of bone mineral content (BMC), bone mineral density (BMD), and bone width (BW) of the forearm. The SPA and DXA measurements were done on the same subjects, using Lunar densitometers. The measurements were performed over the proximal radius (1/3 shaft) of the nondominant arm in 285 healthy, Caucasian females and males, ages 9-53. Correlation, linear, and split regression analyses for all subjects, and for subgroups (adults and children), were performed to compare SPA and DXA measurements. Corresponding measurements performed on two densitometers were highly correlated: r = 0.987, 0.975, and 0.943 for BMC, BMD, and BW, respectively. The corresponding measurements were also very similar in value, ranging from 0.9% to 4.1% difference, although they were different statistically. Correlations dropped slightly when subjects were separated into adult and children subgroups, and therefore, split regression analysis was performed resulting in R2 (adjusted) values of 97.6%, 95.5%, and 89.0% for BMC, BMD, and BW, respectively. Because the group indicator was statistically significant (p < 0.001) only for the BMC measurements but not for BMD and BW, linear regression of the whole sample was done as well. The difference in fitted values between the two regression methods was insignificant; therefore, we concluded that linear regression was sufficient for description of the relationship between SPA and DXA measurements. The precision study showed that the DXA had better reproducibility than SPA. The DXA precision in vivo (CV%) for BMC, BMD, and BW was 1.06, 0.83, and 0.95, respectively; and the SPA precision for same variables was 2.08, 2.12, and 0.95, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
我们比较了单光子吸收测定法（SPA）和双能X线吸收测定法（DXA）用于测定前臂的骨矿物质含量（BMC）、骨矿物质密度（BMD）和骨宽度（BW）。使用Lunar骨密度仪对同一组受试者进行SPA和DXA测量。在285名年龄为9至53岁的健康白种女性和男性的非优势臂近端桡骨（骨干1/3处）进行测量。对所有受试者以及亚组（成人和儿童）进行相关性、线性和分段回归分析，以比较SPA和DXA测量结果。在两台骨密度仪上进行的相应测量具有高度相关性：BMC、BMD和BW的相关系数r分别为0.987、0.975和0.943。相应测量值也非常相似，差异范围为0.9%至4.1%，尽管在统计学上它们有所不同。当将受试者分为成人和儿童亚组时，相关性略有下降，因此进行了分段回归分析，结果BMC、BMD和BW的调整后R2值分别为97.6%、95.5%和89.0%。由于组指标仅在BMC测量中具有统计学显著性（p<0.001），而在BMD和BW测量中不显著，因此也对整个样本进行了线性回归。两种回归方法的拟合值差异不显著；因此，我们得出结论，线性回归足以描述SPA和DXA测量之间的关系。精密度研究表明，DXA的可重复性优于SPA。DXA在体内对BMC、BMD和BW的精密度（CV%）分别为1.06、0.83和0.95；相同变量的SPA精密度分别为2.08、2.12和0.95。（摘要截断于250字）
