Table 4.

Percentage difference of the dual-energy ratio (DER) generated at dual-energy virtual monochromatic spectral (60:80 keV) and single-energy CT (80:140 kVp), for each element and phantom size. A positive value indicates a higher DER at DECT VMS.

	Percentage difference between VMS and SECT DERs at a phantom effective diameter of:
Element	257 mm	323 mm	378 mm	438 mm
Calcium	−1.3	−6.2	0.8	5.5
Iodine	−4.7	−9.3	−10.2	−2.6
Barium	−4.8	−7.5	−10.2	−7.5
Gadolinium	−2.1	2.4	−3.6	−7.3
Tantalum	4.5	9.3	−1.3	12.4
Tungsten	5.6	16.6	3.7	13.6
Bismuth	−7.3	−4.6	−4.7	7.6