X-ray spectra for bone quality assessment using energy dispersive counting and imaging detectors with dual energy method

Abstract

The aim of the present study was the optimization of dual energy x-ray spectra through the estimation of the Coefficient of Variation (CV). The simulation of monoenergetic x-ray beams provides the optimum dual energy pairs minimizing the CV. Single and double exposure methods were used in order to obtain polyenergetic spectra. K-edge filtering was applied to provide quasi-monochromatic beams with equal mean energy to the corresponding monochromatic ones. Furthermore the optimization for the obtained incident spectra was based on a limiting number of counts equal to 105 (CVinc≤0.3%) with minimum peak spectral width. The optimum results for single exposure method obtained from 80kVp with added beam filtration of 850μm Ce achieving a CV value of 0.21%. Whereas for the double exposure technique a CV value of 0.68% was achieved using 50 and 120kVp with added filtration of 400μm Ce and 1000μm Yb respectively. These CV values indicate that this method can be used as a diagnostic tool of great importance in bone quality assessment. © Springer International Publishing Switzerland 2014.