BMD-based assessment of local porosity in human femoral cortical bone
BMD-based assessment of local porosity in human femoral cortical bone
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DOI：
10.1016/j.bone.2018.05.028
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发表时间：
2018-09-01
期刊：
影响因子：
4.1
通讯作者：
Raum, Kay
中科院分区：
文献类型：
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作者：
Iori, Gianluca;Heyer, Frans;Raum, Kay
皮质孔是骨组织弹性和极限强度的决定因素。整体皮质孔隙率 (Ct.Po) 的增加以及大孔隙的局部合并会导致骨的机械能力受损。因此，Ct Po 代表了识别高骨折风险患者的相关目标。然而，由于其尺寸较小，皮质孔的体内成像仍然具有挑战性。现代高分辨率外周定量计算机断层扫描 (HR-pQCT) 的出现引发了通过孔分割或利用局部骨矿物质密度 (BMD) 来临床评估外周骨骼 Ct Po 的新方法。在这项工作中，我们将基于 BMD 的 Ct.Po 估计值与扫描声学显微镜测量的高分辨率参考值进行了比较。通过实验得出了根据 HR-pQCT 评估的 BMD 估计局部 Ct.Po 的校准规则。在小于 0.5 mm(2) 的感兴趣区域内，我们的模型能够估计局部 Ct.Po，误差为 3.4%。与基于平均 BMD 的估计相比，BMD 均匀性和整个扫描体积 BMD 分布的一个参数的结合导致估计误差相对减少了 30%。当应用于评估整个皮质骨横截面内的 Ct.Po 时，所提出的基于 BMD 的方法比使用传统的基于阈值的方法进行的测量具有更好的准确性。
Cortical pores are determinants of the elastic properties and of the ultimate strength of bone tissue. An increase of the overall cortical porosity (Ct.Po) as well as the local coalescence of large pores cause an impairment of the mechanical competence of bone Therefore, Ct Po represents a relevant target for identifying patients with high fracture risk. However, given their small size, the in vivo imaging of cortical pores remains challenging. The advent of modern high-resolution peripheral quantitative computed tomography (HR-pQCT) triggered new methods for the clinical assessment of Ct Po at the peripheral skeleton, either by pore segmentation or by exploiting local bone mineral density (BMD) In this work, we compared BMD-based Ct.Po estimates with highresolution reference values measured by scanning acoustic microscopy. A calibration rule to estimate local Ct.Po from BMD as assessed by HR-pQCT was derived experimentally. Within areas of interest smaller than 0.5 mm(2), our model was able to estimate the local Ct.Po with an error of 3.4%. The incorporation of the BMD mhomogeneity and of one parameter from the BMD distribution of the entire scan volume led to a relative reduction of the estimate error of 30%, if compared to an estimate based on the average BMD. When applied to the assessment of Ct.Po within entire cortical bone cross-sections, the proposed BMD-based method had better accuracy than measurements performed with a conventional threshold-based approach.