Fig. 1

Computed tomography (CT) images. A A CT image taken at age one. No identifiable lesion suggestive of aneurysm. B Axial CT image on admission. The plain CT shows brain swelling, hydrocephalus with intraventricular hemorrhage. C Hyperdense material in the basal cistern, intraventricular hemorrhage in the left lateral and fourth ventricles, as well as a round lesion (encircled) at the left pontocerebellar cistern, indicating intracerebral aneurysm. D CT angiography reveals a large dome-shaped aneurysm (arrow) measuring 15 mm of the left posterior cerebral artery. E 3D-reconstruction image shows a saccular aneurysm in the left P2 segment (arrow)