Our aim was to examine the feasibility of a computed tomographic angiography (CTA) protocol using a reduced dose of high-concentration contrast material on a 16 multidetector-row system to visualize both cervical and cerebral arteries in one session. In 31 consecutive patients, we performed CTA covering the cervical and cerebral arteries. The patients were assigned to one of three groups: group A, 100 mL of 300 mgI/mL; group B, 80 mL of 370 mgI/mL; and group C, 60 mL of 370 mgI/mL followed by a 30-mL saline flush. Arterial enhancements were quantified by measuring attenuation values of the common carotid artery, internal jugular vein, proximal middle cerebral artery (MCA), basilar artery, and straight sinus on source images. Visualizations of the carotid bifurcation and arteries continuing to the circle of Willis were rated on a three-point grading scale on CTA images for qualitative assessment. There were no statistically significant differences in attenuation of all the target vessels among the three groups, with the one exception being a lower attenuation of the MCA in group C than in groups A and B (P < 0.01). Neither were there any significant differences noted among the three groups on the visual assessment. Use of a reduced dose of high iodine concentration contrast material may provide an equal degree of image quality for CTA covering the craniocervical region on a 16 multidetector-row system.