Washio H, et al. - Fifty subjects with head and neck cancer were randomized into two groups, group A, without a saline flush (SF) and group B, with a 30-ml SF by the researchers in order to assess the impact of the SF technique on the imaging of lesions and the reduction of perivenous artefacts in the head and neck region using dual-energy computed tomography (CT) with virtual monochromatic imaging (VMI). All images were obtained via fast kilovolt-switching CT. For group A and for group B, the optimal energy level was 63 keV and 61 keV, respectively. The contrast-to-noise ratios (CNR) was greater for group B, at VMI energy levels ranging from 40 to 80 keV. At the optimal energy level, the highest subjective overall image quality was demonstrated for group B. Subjective delineation of tumors was comparable. For group B, the perivenous artefact score was markedly greater. Hence, an enhancement of lesion CNR and a decrease of perivenous artefacts in VMI using duel-energy CT, especially at 40 keV by the SF technique was concluded.