Ratio of the PFM predictions to the DLC-146 reference cross-section data for selected elements. (a) Total linear attenuation coefficient (single fit); (b) total linear attenuation coefficient (double fit); (c) frequency of photoelectric absorption collisions (double fit); and (d) mass-energy absorption coefficients (double fit).
Ratio of the BVM predictions to the DLC-146 reference cross-section data for the same elements shown in Fig. 1. (a) Total linear attenuation coefficient (single-basis pair); (b) total linear attenuation coefficient (double-basis pair); (c) frequency of photoelectric absorption collisions (double-basis pair); and (d) mass-energy absorption coefficients (double-basis pair). Note that (a) and (b) have a more magnified -axis scale compared with Figs. 1(a) and 1(b), while panels (c) and (d) have the same -axis scale in both Figs. 1 and 2.
The MPAE (mean percent absolute error over the to energy range) of idealized dual-energy scanning of elemental materials as a function of atomic number for (a) the single- and double-basis pair BVM model and (b) the double- or single-fit PFM QDECT analysis. Total attenuation (solid line) and energy absorption (broken line) linear coefficients are shown along with frequency of photoelectric absorption for the BVM QDECT analysis only. Red lines denote double fit or basis pair and blue lines denote single fits or basis pairs.
Ratios of effective to actual atomic numbers and electron densities for elements from the PFM QDECT analysis.
Comparison of simulated QDECT cross-section predictions derived from the double-pair BVM [left column graphs (a), (c), and (e)] and the double-fit PFM [right column, graphs (b), (d), and (f)]. Each graph compares the QDECT prescription with the DLC-146 reference cross section for selected mixtures as a function of energy from . The top, middle, and bottom rows show, respectively, the total linear attenuation coefficient [graphs (a) and (b)], the frequency of photoelectric collisions [graphs (c) and (d)], and the mass-energy absorption coefficient [graphs (e) and (f)].
Percent unexpanded uncertainty of linear attenuation coefficients at the indicated energy for PMMA (blue lines) and a sodium chlorate solution (red lines) for idealized QDECT measurements based on (a) the double basis-pair BVM and (b) the double-fit PFM. The number pairs in parentheses, shown in the legends, denote the standard deviations of the 45- and image intensities, respectively, as percentages of the attenuation coefficient relative to water.
Composition and physical properties of basis substances and selected mixtures used to test the BVM. Aqueous solutions are specified as percent by weight.
Best fit parameters for the PFM model fit to DLC-146 cross-section data for energies of and .
MPAE in , , and values predicted by double-pair BVM and double-fit PFM dual-energy CT analysis over the energy range for selected mixtures. The BVM partial mass densities are also tabulated.
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