When Anatomy Mimics Pathology: Basilar Artery Web on CT Angiography

A 40-year-old woman with severe headache and a family history of cerebral aneurysm underwent non-contrast head CT, which showed nonspecific findings. Intracranial CT angiography revealed a focal intraluminal defect in the proximal third of the basilar artery, consistent with a thin intraluminal membrane, characteristic of a basilar artery web. The patient was managed conservatively and remains under clinical follow-up.