Material Quantification Using Spectral Computed Tomography

Abstract

The aim of this work is to evaluate a linear algebra technique for materials quantification using spectral Computed Tomography (CT). The MARS spectral microCT system incorporating Medipix3 was used to acquire spectroscopic CT data from phantoms containing (i) calcium chloride solutions of various concentrations and (ii) sunflower oil and discrete solutions of iodine, ferric nitrate and calcium chloride. These data were used to establish the linearity of the system and to calibrate the spectroscopic response for different materials of interest. The validity of the proposed materials analysis method was determined by analysis of the information entropy and degrees of freedom associated with the inverse calibration matrix. It is concluded that materials analysis is viable using the proposed linear algebra method for some of the materials of interest and the efficacy of the method is improved with the use of appropriate volume constraints. However the method may not be able to independently distinguish iron, calcium, oil and water without additional data and/or constraints. 