| Autor: |
Saparin, Peter I., Gowin, Wolfgang, Kurths, Ju¨rgen, Felsenberg, Dieter |
| Předmět: |
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| Zdroj: |
AIP Conference Proceedings; 2000, Vol. 502 Issue 1, p550, 7p, 10 Graphs |
| Abstrakt: |
We introduce a generalization of symbolic dynamics to analyze two-dimensional objects and propose measures of complexity to quantify the structure of symbol encoded images. This technique is applied to evaluate the architecture of human cancellous bone by analyzing computed tomography images of vertebrae acquired from specimens and in vivo. The pixels of the preprocessed images are encoded using a mixture of static and dynamic encoding. The architecture of encoded cancellous bone is evaluated as a whole using measures of complexity. A set of new parameters are introduced to quantify the different aspects of structure: complexity and degree of disorder of the architecture as a whole, or spatial arrangements of hard or soft elements of the bone separately. It is found that the complexity of the bone structure relates to its density exponentially. Normal bone has a complex ordered structure, while the architecture during the initial stage of bone loss is characterized by lower complexity and a maximal level of disorder. Increased bone loss leads again to ordered structure, however, its complexity is minimal. This phenomenon was observed in a series of osteoporotic specimens as well as in vivo in patients treated with fluor, and hormone replacement therapy. We found that different bone diseases demonstrate distinctive features captured by the measurements of complexity of the bone’s structural composition. It is shown that the application of the proposed technique leads to new insights for understanding of the bone’s response on medical treatment and provide important additional information for the diagnostics of bone diseases. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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