title: Polynomial dual energy inverse functions for bone Calcium/Phosphorus ratio determination and experimental evaluation.
abstract: An X-ray dual energy (XRDE) method was examined, using polynomial nonlinear approximation of inverse functions for the determination of the bone Calcium-to-Phosphorus (Ca/P) mass ratio. Inverse fitting functions with the least-squares estimation were used, to determine calcium and phosphate thicknesses. The method was verified by measuring test bone phantoms with a dedicated dual energy system and compared with previously published dual energy data. The accuracy in the determination of the calcium and phosphate thicknesses improved with the polynomial nonlinear inverse function method, introduced in this work, (ranged from 1.4% to 6.2%), compared to the corresponding linear inverse function method (ranged from 1.4% to 19.5%).
authors: Department of Medical Physics, Medical School, University of Patras, Rion, 26500 Patras, Greece.
authors: P
authors: P
authors: Sotiropoulou
authors: Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo, 12210 Athens, Greece. Electronic address: gfoun@teiath.gr.
authors: G
authors: G
authors: Fountos
authors: Department of Medical Physics, Medical School, University of Patras, Rion, 26500 Patras, Greece.
authors: N
authors: N
authors: Martini
authors: Department of Medical Physics, Medical School, University of Patras, Rion, 26500 Patras, Greece.
authors: V
authors: V
authors: Koukou
authors: Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo, 12210 Athens, Greece.
authors: C
authors: C
authors: Michail
authors: Radiation Physics, Materials Technology and Biomedical Imaging Laboratory, Department of Biomedical Engineering, Technological Educational Institute of Athens, Egaleo, 12210 Athens, Greece.
authors: I
authors: I
authors: Kandarakis
authors: Department of Medical Physics, Medical School, University of Patras, Rion, 26500 Patras, Greece.
authors: G
authors: G
authors: Nikiforidis
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D000465:Algorithms; D001842:Bone and Bones / Q000737:chemistry*; D002118:Calcium / Q000032:analysis*; D003198:Computer Simulation; D006801:Humans; D015233:Models, Statistical; D009716:Numerical Analysis, Computer-Assisted; D019047:Phantoms, Imaging; D010758:Phosphorus / Q000032:analysis*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D010758:Phosphorus; D002118:Calcium
keywords: Bone; Calcium/Phosphorus ratio; Dual energy; Polynomial inverse functions; X-ray