Bone calcium/phosphorus ratio determination using dual energy X-ray method.
Non-invasive dual energy methods have been used extensively on osteoporosis diagnosis estimating parameters, such as, Bone Mineral Density (BMD) and Bone Mineral Content (BMC). In this study, an X-ray dual energy method (XRDE) was developed for the estimation of the bone Calcium-to-Phosphorous (Ca/P) mass ratio, as a bone quality index. The optimized irradiation parameters were assessed by performing analytical model simulations. X-ray tube output, filter material and thickness were used as input parameters. A single exposure technique, combined with K-edge filtering, was applied. The optimal X-ray spectra were selected according to the resulted precision and accuracy values. Experimental evaluation was performed on an XRDE system incorporating a Cadmium Telluride (CdTe) photon counting detector and three bone phantoms with different nominal mass Ca/P ratios. Additionally, the phantoms' mass Ca/P ratios were validated with energy-dispersive X-ray spectroscopy (EDX). Simulation results showed that the optimum filter atomic number (Z) ranges between 57 and 70. The optimum spectrum was obtained at 100 kVp, filtered with Cerium (Ce), with a surface density of 0.88 g/cm(2). All Ca/P ratio measurements were found to be accurate to within 1.6% of the nominal values, while the precision ranged between 0.91 and 1.37%. The accuracy and precision values of the proposed non-invasive method contributes to the assessment of the bone quality state through the mass Ca/P ratio determination.
Department of Medical Physics, Medical School, University of Patras, Rion, 265 00 Patras, Greece.
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Sotiropoulou
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo, 122 10 Athens, Greece. Electronic address: gfoun@teiath.gr.
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Fountos
Department of Medical Physics, Medical School, University of Patras, Rion, 265 00 Patras, Greece.
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Martini
Department of Medical Physics, Medical School, University of Patras, Rion, 265 00 Patras, Greece.
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Koukou
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo, 122 10 Athens, Greece.
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Michail
Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo, 122 10 Athens, Greece.
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Kandarakis
Department of Medical Physics, Medical School, University of Patras, Rion, 265 00 Patras, Greece.
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Nikiforidis
D015502:Absorptiometry, Photon; D015519:Bone Density; D001842:Bone and Bones / Q000378:metabolism* / Q000502:physiology; D019187:Cadmium Compounds; D002118:Calcium / Q000378:metabolism*; D006801:Humans; D010024:Osteoporosis / Q000175:diagnosis; D019047:Phantoms, Imaging; D010758:Phosphorus / Q000378:metabolism*; D013691:Tellurium
D019187:Cadmium Compounds; D010758:Phosphorus; D013691:Tellurium; C028337:cadmium telluride; D002118:Calcium
Bone; CdTe; Dual energy; Hydroxyapatite