system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A patient with suspected subarachnoid haemorrhage presents with blood isolated in the fouh ventricle on a CT scan. Aneurysmal rupture is likely to have resulted from
assistant
The correct answer is  *Saccular aneurysm at size of >7mm and at top of basilar aery and at origin of posterior communicating aery are at greater risk of rupture . Ref Harrison20th edition pg 2445