Super-selective intra-arterial infusion chemotherapy for head and neck cancer via the superficial temporal artery is an established procedure. Three-dimensional computed tomography angiography (3D-CTA) has often been used to assess the arterial anatomy. However, 3D-CTA images are sometimes affected by severe metallic artifacts near the oral cavity region, due to the presence of metallic dental materials. This study has evaluated 3-dimensional intravenous digital subtraction angiography (3D-IV-DSA) using a flat panel detector (FPD) system in vascular mapping of the external carotid artery (ECA), in comparison with 3D-CTA. To clarify the vascular anatomy of ECA branches, 15 patients had undergone both 3D-IV-DSA and 3D-CTA. The angiographic images of the ECA were generated using a volume-rendering technique. The 15 patients were also divided into two groups according to the existence of adverse effects due to dental metallic artifacts on 3D-CTA.Images from 3D-IVDSA were statistically significantly superior to 3D-CTA (P < 0.05). In particular, when metallic artifacts affected 3DCTA images, 3D-IV-DSA was able to depict the ECA more clearly. These findings confirm the utility of 3D-IV-DSA, and the technique may be particularly suitable for patients with metallic dental materials.