FRACTAL DIMENSION PREDICTS BROAD-BAND ULTRASOUND ATTENUATION IN STEREOLITHOGRAPHY MODELS OF CANCELLOUS BONE

There has been considerable debate on the relative dependence of broad band ultrasound attenuation (nBUA, dB MHz(-1) cm(-1)) upon the density and structure of cancellous bone. A nonlinear relationship between nB UA and porosity has recently been demonstrated using stereolithography models, indicating a high structural dependence for nBUA. We report h ere on the measurement of trabecular perimeter and fractal dimension o n the two-dimensional images used to create the stereolithography mode ls. Adjusted coefficients of determination (R-2) with nBUA were 94.4% (p < 0.0001) and 98.4% (p < 0.0001) for trabecular perimeter and fract al dimension respectively. The feature of fractal dimension representi ng both the porosity and connectivity of a given structure is most exc iting. Further work is required to determine the relationship between broadband ultrasound attenuation and fractal dimension in complex thre e-dimensional cancellous bone structures.