Lees B, Garland S W, Walton C, Stevenson J C
Wynn Division of Metabolic Medicine, Imperial College School of Medicine, National Heart and Lung Institute, London, UK.
Osteoporos Int. 1997;7(6):570-4. doi: 10.1007/BF02652564.
The European Spine Phantom (ESP) has recently been developed as a universal standard for instruments measuring bone density. The ESP is composed of three semi-anthropomorphic hydroxyapatite vertebrae of varying densities surrounded by soft tissue equivalent plastic designed to resemble human bone and soft tissue when scanned on bone densitometers. In multi-centre studies it is particularly important to verify that each participating bone densitometer is performing in a stable and linear fashion. The aim of this study was to evaluate the ESP within the context of a multi-centre clinical trial. Eighteen centres in the UK and Canada with dual-energy X-ray absorptiometry (DXA) instruments (Lunar DPX, DPX-alpha and DPX-L) participated in the study. The ESP was scanned 10 times on each instrument without repositioning using standardized protocols. The precision of the bone mineral density (BMD) measurements (LI-3) expressed as a coefficient of variation ranged from 0.4% to 1.1% (mean 0.7%). The mean BMD of each instrument was expressed as a percentage difference from the overall mean and ranged from -1.33% to 1.33%. Linear regression analysis showed that all instruments behaved in a linear fashion across the range of densities with correlation coefficients all > or = 0.999 and standard errors of the estimate < 1.5% of the mean BMD ESP value. The data from this study demonstrate that the ESP is a useful phantom for assessing the linearity, stability and differences between DXA instruments from one manufacturer.
欧洲脊柱体模（ESP）最近已被开发出来，作为测量骨密度仪器的通用标准。ESP由三个密度不同的半人体形态的羟基磷灰石椎骨组成，周围环绕着软组织等效塑料，设计目的是使其在骨密度仪上扫描时类似于人体骨骼和软组织。在多中心研究中，特别重要的是要验证每台参与的骨密度仪是否以稳定和线性的方式运行。本研究的目的是在多中心临床试验的背景下评估ESP。英国和加拿大的18个中心使用双能X线吸收仪（DXA）仪器（Lunar DPX、DPX-alpha和DPX-L）参与了该研究。按照标准化方案，在每台仪器上对ESP进行10次扫描，且不重新定位。以变异系数表示的骨矿物质密度（BMD）测量（LI-3）的精密度范围为0.4%至1.1%（平均0.7%）。每台仪器的平均BMD表示为与总体平均值的百分比差异，范围为-1.33%至1.33%。线性回归分析表明，所有仪器在密度范围内均呈线性，相关系数均≥0.999，估计标准误差<平均BMD ESP值的1.5%。本研究的数据表明，ESP是一种有用的体模，可用于评估来自同一制造商的DXA仪器之间的线性、稳定性和差异。
