Table 2.

Image data sets acquired from dual-energy CT (DECT), basic principles and the advantages over single-energy CT (SECT)

Images	Basic principle	Advantages
High-kV and low-kV images	Two sets of information derived from different energy levels; main characteristic of DECT	Provides attenuation value of every voxel at two energy levels
VNC images	Material differentiation property helps in subtracting iodine from the data set	Reduces radiation dose to the patient by avoiding the acquisition of unenhanced images
VMC images	Obtained by extrapolating the DECT data to generate images at specified single-energy levels (range: 40–150 keV)	Helps in metallic artefact reduction and allows lower dose of iodinated contrast material
Weighted average images	Obtained by linear blending of data from two energy levels	The images mimic SECT images and are sent to PACS for interpretation
Iodine overlay images	Colour codes the distribution of iodine within the voxel	Allows objective assessment of contrast enhancement and vascularity
Automated bone removal	Subtraction of calcium from the data set	Quick and accurate bone removal

kV, kilovoltage; PACS, picture archiving and communication system; VMC, virtual monochromatic; VNC, virtual non-contrast.