Figure 1.

A: Head CT scan shows that the hemorrhage was localized on the pontine cistern and interpeduncular cistern, extending to the right of the ambient cistern, into the posterior horn of the right ventricle. The patient was diagnosed with subarachnoid hemorrhage (SAH). B: Head CT angiograph shows mound-like protuberances at the apex of the basilar artery with a diameter of 3.2 mm, no signal at the bilateral internal carotid artery, and bilateral posterior communicating artery supplying the circulation.