X-ray spectra optimization using lanthanide and non elements for bone quality assessment with Dual Energy method

• Κύριος συγγραφέας: Μαρτίνη, Νίκη
• Άλλοι συγγραφείς: Νικηφορίδης, Γιώργος
• Μορφή: Thesis
• Γλώσσα: English
• Έκδοση: 2013
• Θέματα: Dual energy; Ca/P ratio; HAp/Col ratio; Διπλή ενέργεια; Λόγος Ca/P; Λόγος HAp/Col; 616.716 075 72

Osteoporosis is a disease of the bones. It is often called the “silent disease," because someone could have it now or be at-risk without even realizing it. As a result, bones become weak and can break from a minor fall or, in serious cases, even from simple actions, like sneezing or bumping into furniture. Breaking a bone is often the first clue that someone suffers from osteoporosis. The diagnosis of osteoporosis can be made using conventional radiography and by measuring the Bone Mineral Density (BMD). The most popular method of measuring BMD is Dual-Energy X-ray Absorptiometry (DXA). In conventional methods the measurement of bone does not give information about the bone quality but for the bone quantity. A non-invasive method that will have the ability to determine the bone quality is of interest. Such a method will contribute to the prediction or even the prevention of bone malfunction. In this study, two quality parameters, that are designed to contribute to improved diagnostic methods of osteoporosis, are determined. Those bone quality parameters are the Calcium/Phosphate (Ca/P) and Hydroxyapatite/Collagen (HAp/Col) ratios. The algorithm developed allows us to trace the spectral changes which take place when an x-ray beam passes through filters based on the Lambert and Beer’s law. A large number of filters were applied to spectra so as to obtain pseudo-monoenergetic spectra. The optimum energy pair would derive from two quasi-monoenergetic spectra with sufficient number of photons which will result in the minimization of the Coefficient of Variation (CV) of the aforementioned ratios. Dual Energy x-ray method is used in order to obtain this energy pair. Both Single and Double exposure techniques are used.