Jiang Yaojun, Wu Yan, Zhang Yonggao, Yang Xiaopeng, Gao Jianbo
Department of Radiology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
Quant Imaging Med Surg. 2023 Apr 1;13(4):2119-2127. doi: 10.21037/qims-22-619. Epub 2023 Feb 6.
For bone health assessment, dual-energy X-ray absorptiometry (DEXA) is recommended to measure bone mineral content and areal bone mineral density (aBMD) in the lumbar spine. However, intermachine differences were not taken into account when developing these recommendations. According to the International Society of Clinical Densitometry (ISCD), phantom-based cross-calibration is adequate after replacing the DEXA system from a different manufacturer. For different DEXA equipment, individual calibration equations were found to be necessary to fit the observed values with the given densities.
The BMD European Spine Phantom (ESP) measurements (L1, L2, and L3) were assessed on 3 machines. We used the Welch test in the one-way analysis of variance (ANOVA) with a Tamhane T2 test, linear regressions, and Bland-Altman analysis to assess the consistency of measurements and establish cross-calibration equations.
The coefficients of variation (CV)% of the phantom BMD values measured using the 3 systems were less than 3.0%. The 3 DEXA systems were highly correlated with BMD in the lumbar spine, with correlation values ranging from 0.933 to 0.984 (P<0.0001). The cross-calibration regression models of the ESP measurements yielded the highest prediction accuracies with the lowest prediction errors (the standard error of the estimate ranged from 0.004 to 0.008 g/cm; P<0.0001). After the regression equations were applied, the differences in BMD values among the 3 systems were negligible. In addition, the Bland-Altman plot showed that almost all data points were within the 95% limits of agreement.
A strong agreement for BMD measurement was established between the 3 DEXA systems. Cross-calibration equations for the lumbar spine BMD values need to be applied to transform the Hologic Discovery A or GE Lunar iDXA measurements into SONIALVISION SMIT measurements to comply with the ISCD standards for patient continuity of care in assessment during clinical diagnosis.
对于骨健康评估，推荐使用双能X线吸收测定法（DEXA）测量腰椎的骨矿物质含量和面积骨矿物质密度（aBMD）。然而，在制定这些建议时未考虑不同仪器之间的差异。根据国际临床骨密度测量学会（ISCD）的说法，在更换不同制造商的DEXA系统后，基于体模的交叉校准是足够的。对于不同的DEXA设备，发现需要单独的校准方程才能使观测值与给定密度相拟合。
在3台仪器上对BMD欧洲脊柱体模（ESP）进行测量（L1、L2和L3）。我们在单因素方差分析（ANOVA）中使用韦尔奇检验，并结合塔姆哈尼T2检验、线性回归和布兰德-奥特曼分析来评估测量的一致性并建立交叉校准方程。
使用这3种系统测量的体模BMD值的变异系数（CV）%均小于3.0%。这3种DEXA系统与腰椎BMD高度相关，相关值范围为0.933至0.984（P<0.0001）。ESP测量的交叉校准回归模型产生了最高的预测精度和最低的预测误差（估计标准误差范围为0.004至0.008 g/cm；P<0.0001）。应用回归方程后，这3种系统之间的BMD值差异可忽略不计。此外，布兰德-奥特曼图显示几乎所有数据点都在95%一致性界限内。
在这3种DEXA系统之间建立了关于BMD测量的高度一致性。需要应用腰椎BMD值的交叉校准方程，将Hologic Discovery A或GE Lunar iDXA测量值转换为SONIALVISION SMIT测量值，以符合ISCD关于临床诊断评估中患者连续护理的标准。
