Intracranial aneurysm (localized dilatation in weakened blood vessel wall) rupture is a catastrophic disease, with half of the victims died and many of the survivors disabled. There is currently no data in the literature for the Chinese population concerning the prevalence, characteristics (location and size) and risk of harboring an unruptured intracranial aneurysm. In this study, the investigators aim to study the population prevalence and characteristics (location and size) of intracranial aneurysm in Hong Kong Chinese, and its cost-effectiveness. The screening is carried out using magnetic resonance angiography (MRA), with a 3-T magnetic resonance system, which is a well-established non-invasive method for intracranial aneurysm detection.

As charted below.

Inclusion Criteria:

• Healthy adults aged between 21 and 65 years

Exclusion Criteria:

• Contraindications to MRI
• History of known intracranial pathologies

Hong Kong Chinese without a history of known intracranial pathologies