Application of polychromatic μcT for mineral density determination

Accurate assessment of mineral density (md) provides information critical to the understanding of mineralization processes of calcified tissues,including bones and teeth. high-resolution three-dimensional assessment of the md of teeth has been demonstrated by relatively inaccessible synchrotron radiation microcomputed tomography (srμct). while conventional desktop μct (cμct) technology is widely available,polychromatic source and cone-shaped beam geometry confound md assessment. recently,considerable attention has been given to optimizing quantitative data from cμct systems with polychromatic x-ray sources. in this review,we focus on the approaches that minimize inaccuracies arising from beam hardening,in particular,beam filtration during the scan,beam-hardening correction during reconstruction,and mineral density calibration. filtration along with lowest possible source voltage results in a narrow and near-single-peak spectrum,favoring high contrast and minimal beam-hardening artifacts. more effective beam monochromatization approaches are described. we also examine the significance of beam-hardening correction in determining the accuracy of mineral density estimation. in addition,standards for the calibration of reconstructed grey-scale attenuation values against md,including k2pho4 liquid phantom,and polymer- hydroxyapatite (ha) and solid hydroxyapatite (ha) phantoms,are discussed. © 2011 international & american associations for dental research.