<title>Change in trabecular architecture as measured by fractal dimension</title>

Abstract

Detection of subtle structural changes in trabecular bone is important in evaluating the load- bearing capability of whole bones. Microstructural changes in trabecular bone due to remodeling or resorption lead to changes in bone strength. Recently, fractal-based analyses of radiographs have demonstrated that a fractal model can describe trabecular bone patterns independent of mass density. In this case, the descriptor of choice is a scale-invariant measure of trabecular detail known as fractal dimension. The objective of this work was to compare two measures of the distribution of trabecular bone -- fractal dimension and mean gray level -- in a decalcifying environment. The fractal-based analysis relied upon the spatial distribution of trabecular material while the mean gray level measurements depended upon the average x- radiation attenuation over a region of interest. Data were produced from four separate slices of vertebral bone which demonstrated that a change in the spatial distribution of trabecular material may be expressed in terms of a concurrently changing estimate of the fractal dimension within a region of interest. This change was not necessarily reflected in the mean gray level estimate of mass density.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.