3d Measures of Complexity for the Assessment of Complex Trabecular Bone Structures

For the assessment of bone stage (e.g. regarding different osteoporotic stages), usually the bone mineral density (BMD) is measured. However, this measurement does not contain any information about the structures inside the bone. Recent work emphasized the importance of analysing the structural changes of trabecular bone (Guo & Kim, 2002; Silva & Gibson, 1997). Different approaches for the study of trabecular bone were successfully introduced for 2D image analysis, as measures of complexity based on symbolic dynamics. The new available 3D bone images (μCT-data) challenge the development of new 3D measures of complexity, which are able to assess structural changes in trabecular bone. We consider here new developments of 3D measures based on spatial correlation and geometrical properties: Moran’s I Index and Shape Index. Histomorphometrical measures are used for comparison with the “golden standard” of investigation of trabecular bone (Thomsen et al., 2000). All of this is work in progress, which means that these measures may not yet be perfect and that the presented results are preliminary.