Quantifying Changes in the Spatial Structure of Trabecular Bone

We apply recently introduced measures of complexity for the structural quantfication of distal tibial bone. For the first time, we are able to investigate the temporal structural alteration of trabecular bone. Based on four patients, we show how bone may alter due to temporal immobilisation

DESCRIPTION AND DIAGNOSTICS FOR COMPLEX REGIMES OF SELF-OSCILLATIONS ON EXPERIMENTAL DATA

Dynamic systems, time series, generators of complex and chaotic signals are considered in the paper aiming at the creation of new algorithms, detailed investigations of particular features and effectiveness for the description and diagnostics of complex regimes in systems, containing noise sources, on experimental data. As a result the calculation algorithm for a new effective characteristic - overnormed entropy has been developed. The ordering degree for regimes of the transition to chaos has been investigated. The new method for the determination of a bifurcation point on experimental data has been suggested. Recommendations for the optimum choice of quantitative characteristics off complex signals have been developed. New high effective characteristics of time series and signals have been introduced. The paper results may find their field of application in radio physical investigations, in the description and diagnostics of regimes on experimental data, the analysis of time series, medical-biological investigationsAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Generalised recurrence plot analysis for spatial data

Abstract-The method of recurrence plots and algorithms for their quantification are extended to analyse spatial data thus allowing to study recurrent structures in 2D images. To verify its capabilities, the method is tested on prototypical 2D models. Next, the developed approach is applied to assess the bone structure from CT images of human proximal tibia. It is found that the spatial structures in trabecular bone become more self-similar during the bone loss in osteoporosis

Quantification of Changes in Spatial Structure of Human Bone Biopsies Using 3D Measures of Complexity.

The aim of the study was to assess the 3D structural composition and deterioration of human bone tissue in osteoporosis using 3D datasets of human tibia bone biopsies acquired by a micro-CT scanner. We applied symbolic dynamics and measures of complexity to assess quantitatively the structural composition of bone tissue in 3D. Originally, these methods were developed and successfully applied for quantification of 2D bone structure from CT-images [1, 2]. Now we apply this approach to assess 3D bone architecture. In order to justify the technique the measures of complexity of the bone architecture ware compared with the results of traditional bone histomorphometry. The biopsies were taken from 30 human bone specimes at the medial side 17 mm distal of the tibia plateau which is a bone harvesting site for surgeons. All biopsies had a diameter of 7 mm; their length varied between 2 and 4 cm. The biopsy cylinders were embedding in methylmetacrylate. The biopsies were scanned with micro-CT scanner (µCT 40) at Scanco Medical AG, Switzerland, using a voxel size of 20 µm. The first step of our technique is symbol-encoding of the dataset which preserves the robust and crucial information about the original structure but dramatically decreases th

Quantification of Spatial Structure of Human Proximal Tibial Bone Biopsies Using 3D Measures of Complexity

Changes in trabecular bone composition during development of osteoporosis are used as a model for bone loss in microgravity conditions during a space flight