Occipital artery arising from the superior aspect of the carotid bifurcation identified by three-dimensional computed tomography angiography

Variation of the branches of the external carotid artery is well known, but it is extremely rare for the occipital artery (OA) to arise from the carotid bifurcation (CB). A 73-year-old man was found to have this anatomical variation on the right side by three-dimensional CT angiography for vascular mapping of the carotid arteries before superselective intra-arterial catheterization. The OA arose from the CB and the inner diameter of the origin of the OA was 1.5 mm. The CB was located at the level of C3-C4 and 7.9 mm above the tip of the greater horn of the hyoid bone. (C) 2017 Anatomical Society of India. Published by Elsevier, a division of RELX India, Pvt. Ltd. All rights reserved.