Engineering Research Center for Computer-Integrated Surgical Systems and Technology, Department of Computer Science, The Johns Hopkins University, Baltimore, MD, USA.
J Bone Miner Res. 2010 Dec;25(12):2744-51. doi: 10.1002/jbmr.140. Epub 2010 Jun 7.
Three-dimensional geometric and structural measurements of the proximal femur are of considerable interest in understanding the strength of the femur and its susceptibility to fracture. Quantitative computed tomography (QCT) with a small voxel size (≤1 mm per side) is the current "gold standard" to examine the macrostructure of the femur, but it has a high effective radiation dose (approximately 2 to 5 mSv) and cost. Volumetric dual-energy X-ray absorptiometry (VXA) uses a commercially available DXA system (Hologic Discovery A) to reconstruct the proximal femur from four DXA scans delivering an effective radiation dose of 0.04 mSv. VXA was compared with QCT (voxel size of 0.29 × 0.29 × 1 mm) in 41 elderly women (age 82 ± 2.4 years) at slices located at the femoral neck and trochanteric regions of interest. For parameters of shape, the femoral neck axis length (FNAL) and the cross-sectional slice area (SA), accuracy and strong linear correlations (r = 0.84 to 0.98) were demonstrated. Similar correlations (r = 0.81 to 0.97) were observed for the density parameters, the cross-sectional bone area (CSA) and volumetric bone mineral density (vBMD). VXA also demonstrated strong correlations (r = 0.76 to 0.99) for the engineering parameters of the minimum, maximum, and polar cross-sectional moments of inertia (CSMIs) and the section modulus (Z). We conclude that VXA is capable of generating a variety of 3D geometric and structural measurements that are highly correlated with QCT in elderly subjects in vivo. Moreover, the VXA measurements can be made with a commercially available DXA device at a very low radiation dose.
对股骨近端的三维几何和结构测量在理解股骨的强度及其骨折易感性方面具有重要意义。具有小体素尺寸（每边≤1 毫米）的定量计算机断层扫描（QCT）是检查股骨宏观结构的当前“金标准”，但它具有较高的有效辐射剂量（约 2 至 5 毫希沃特）和成本。容积双能 X 射线吸收法（VXA）使用市售的 DXA 系统（Hologic Discovery A）从四个 DXA 扫描中重建股骨近端，有效辐射剂量为 0.04 毫希沃特。VXA 与 QCT（体素尺寸为 0.29×0.29×1 毫米）在 41 名老年女性（年龄 82±2.4 岁）中进行了比较，这些女性位于股骨颈和转子感兴趣区域的切片中。对于形状参数，股骨颈轴长（FNAL）和横截面切片面积（SA）具有准确性和强线性相关性（r=0.84 至 0.98）。密度参数也观察到类似的相关性（r=0.81 至 0.97），包括横截面骨面积（CSA）和容积骨矿物质密度（vBMD）。VXA 还对最小、最大和极横截面转动惯量（CSMIs）和截面模数（Z）的工程参数表现出很强的相关性（r=0.76 至 0.99）。我们得出结论，VXA 能够在体内老年患者中生成与 QCT 高度相关的多种 3D 几何和结构测量值。此外，VXA 测量值可以使用市售的 DXA 设备以非常低的辐射剂量获得。
