Langton C M, Whitehead M A, Haire T J, Hodgskinson R
University of Hull, UK.
Phys Med Biol. 1998 Feb;43(2):467-71. doi: 10.1088/0031-9155/43/2/019.
There has been considerable debate on the relative dependence of broadband ultrasound attenuation (nBUA, dB MHz(-1) cm(-1)) upon the density and structure of cancellous bone. A nonlinear relationship between nBUA and porosity has recently been demonstrated using stereolithography models, indicating a high structural dependence for nBUA. We report here on the measurement of trabecular perimeter and fractal dimension on the two-dimensional images used to create the stereolithography models. Adjusted coefficients of determination (R2) with nBUA were 94.4% (p < 0.0001) and 98.4% (p < 0.0001) for trabecular perimeter and fractal dimension respectively. The feature of fractal dimension representing both the porosity and connectivity of a given structure is most exciting. Further work is required to determine the relationship between broadband ultrasound attenuation and fractal dimension in complex three-dimensional cancellous bone structures.
关于宽带超声衰减（nBUA，dB MHz(-1) cm(-1)）对松质骨密度和结构的相对依赖性，一直存在相当多的争论。最近使用立体光刻模型证明了nBUA与孔隙率之间的非线性关系，这表明nBUA对结构有高度依赖性。我们在此报告用于创建立体光刻模型的二维图像上小梁周长和分形维数的测量结果。小梁周长和分形维数与nBUA的调整决定系数（R2）分别为94.4%（p < 0.0001）和98.4%（p < 0.0001）。代表给定结构孔隙率和连通性的分形维数特征最为令人兴奋。需要进一步开展工作来确定复杂三维松质骨结构中宽带超声衰减与分形维数之间的关系。
