Durieux P, et al. - The magnitude of differences between attenuation values measured on virtual and true unenhanced images obtained using third-generation dual-source dual-energy CT (DECT) in patients requiring thoracoabdominal CT for cancer work-up was determined. Abdominal virtual unenhanced images obtained with third-generation dual-source DECT should not replace true unenhanced images due to significant variations in attenuation measurements for fluid, fat, and renal tissues.