Quantitative Imaging of Element Composition and Mass Fraction Using Dual-Energy CT: Three Material Decomposition


In principle, dual-energy CT can only accurately decompose a mixture into two materials. To decompose a mixture into three constitute materials using dual-energy CT measurements, a third criteria must be provided to solve for three unknowns with only two spectral measurements. One solution is to assume that the sum of the volumes of three constituent materials is equivalent to the volume of the mixture (i.e., volume conservation), but this is not always true. A more generalized solution is to use the principle of mass conservation, which assumes that the sum of the masses of the three constituent materials is equivalent to the mass of the mixture. In this article, a mass-conservation based, three-material decomposition dual-energy CT algorithm is described and experimental validation of the accuracy of the technique presented. The results demonstrate that the proposed method can accurately measure elemental concentrations under low noise imaging conditions. Clinically, this may be applied to measure the mass fraction of any chemical element in a three-material mixture of solutions without the requirement of volume conservation.


Nuclear Engineering and Radiation Science

Keywords and Phrases

Computed Tomography; Medical Imaging; Iron; Solution Processes; Medical X-Ray Imaging

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Document Type

Article - Journal

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© 2009 American Association of Physicists in Medicine (AAPM), All rights reserved.

Publication Date

01 Jan 2009