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
Best test to determine etiology of SAH
assistant
The correct answer is  C i.e. Intra aerial digital Substraction Once dx is done by CT Scan; digital substraction angiography (DSA) is done to determine etiology. DSA is most sensitive & best inv. for determining etiologyQ. Now DSA is being replaced by noninvasive methods as MRA (MRI - angiography) & CTA (CT - Angiography).