基于 MRI 的虚拟骨活检在桡骨远端的性能：骨质疏松研究人群中女性代表性的结构和力学参数的系列可重复性和可靠性。

Performance of the MRI-based virtual bone biopsy in the distal radius: serial reproducibility and reliability of structural and mechanical parameters in women representative of osteoporosis study populations.

机构信息

Laboratory for Structural NMR Imaging, Department of Radiology, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.

出版信息

Bone. 2011 Oct;49(4):895-903. doi: 10.1016/j.bone.2011.07.010. Epub 2011 Jul 19.

DOI:10.1016/j.bone.2011.07.010

PMID:21784189

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC3167016/

Abstract

Serial reproducibility and reliability critically determine sensitivity to detect changes in response to intervention and provide a basis for sample size estimates. Here, we evaluated the performance of the MRI-based virtual bone biopsy in terms of 26 structural and mechanical parameters in the distal radius of 20 women in the age range of 50 to 75 years (mean=62.0 years, S.D.=8.1 years), representative of typical study populations in drug intervention trials and fracture studies. Subjects were examined three times at average intervals of 20.2 days (S.D.=14.5 days) by MRI at 1.5 T field strength at a voxel size of 137×137×410 μm(3). Methods involved prospective and retrospective 3D image registration and auto-focus motion correction. Analyses were performed from a central 5×5×5 mm(3) cuboid subvolume and trabecular volume consisting of a 13 mm axial slab encompassing the entire medullary cavity. Whole-volume axial stiffness and sub-regional Young's and shear moduli were computed by finite-element analysis. Whole-volume-derived aggregate mean coefficient of variation of all structural parameters was 4.4% (range 1.8% to 7.7%) and 4.0% for axial stiffness; corresponding data in the subvolume were 6.5% (range 1.6% to 13.0%) for structural, and 5.5% (range 4.6% to 6.5%) for mechanical parameters. Aggregate ICC was 0.976 (range 0.947 to 0.986) and 0.992 for whole-volume-derived structural parameters and axial stiffness, and 0.946 (range 0.752 to 0.991) and 0.974 (range 0.965 to 0.978) for subvolume-derived structural and mechanical parameters, respectively. The strongest predictors of whole-volume axial stiffness were BV/TV, junction density, skeleton density and Tb.N (R(2) 0.79-0.87). The same parameters were also highly predictive of sub-regional axial modulus (R(2) 0.88-0.91). The data suggest that the method is suited for longitudinal assessment of the response to therapy. The underlying technology is portable and should be compatible with all general-purpose MRI scanners, which is appealing considering the very large installed base of this modality.

摘要

序列可重复性和可靠性是确定对干预措施反应变化的敏感性并为样本量估计提供基础的关键。在这里，我们评估了基于 MRI 的虚拟骨活检在 20 名年龄在 50 至 75 岁（平均 62.0 岁，标准差 8.1 岁）女性的桡骨远端 26 个结构和机械参数方面的性能，这些女性代表了药物干预试验和骨折研究中典型的研究人群。受试者在平均 20.2 天（标准差 14.5 天）的间隔内，通过 1.5 T 场强的 MRI 进行了三次检查，体素大小为 137×137×410 μm（3）。方法包括前瞻性和回顾性的 3D 图像配准和自动聚焦运动校正。分析是从一个中央的 5×5×5mm(3)的长方体子体积和由包含整个骨髓腔的 13mm 轴向板的小梁体积进行的。通过有限元分析计算整个体积的轴向刚度和子区域的杨氏和剪切模量。通过所有结构参数的整体体积衍生的平均系数变化率为 4.4%（范围为 1.8%至 7.7%），轴向刚度为 4.0%；子体积中的相应数据为结构参数的 6.5%（范围为 1.6%至 13.0%）和机械参数的 5.5%（范围为 4.6%至 6.5%）。总体 ICC 为 0.976（范围为 0.947 至 0.986）和 0.992 为整体体积衍生的结构参数和轴向刚度，分别为 0.946（范围为 0.752 至 0.991）和 0.974（范围为 0.965 至 0.978）为子体积衍生的结构和机械参数。整体体积轴向刚度的最强预测因子是 BV/TV、连接密度、骨架密度和 Tb.N（R(2) 0.79-0.87）。相同的参数也高度预测了子区域的轴向模量（R(2) 0.88-0.91）。这些数据表明该方法适合于治疗反应的纵向评估。该基础技术具有便携性，应该与所有通用 MRI 扫描仪兼容，考虑到这种模式的非常大的安装基础，这是非常有吸引力的。