Intracranial aneurysms are asymptomatic until rupture occurs. Based on previous autopsies and MR or CT angiography of the cerebral vasculature, 1.5 – 7% of unruptured aneurysms can be detected, and the mortality rate of ruptured intracranial aneurysms is as high as 48%, so it becomes important to know who in the normal population needs cerebrovascular examination to rule out intracranial aneurysms. Who needs a cerebrovascular examination to rule out aneurysm? Patients with two or more immediate family members with a history of ruptured aneurysms; 2. Patients who smoke excessively, drink heavily, or have severe hypertension (the risk of hemorrhagic stroke is 4.5 times higher in smokers than in nonsmokers); 3. Patients with vascular disease, including fibromuscular dysplasia and polycystic kidney; 4. Patients between the ages of 50 and 60. Normal people with the above four conditions are at risk of developing intracranial aneurysms and therefore require cerebrovascular examination to rule out intracranial aneurysms. There are two types of cerebrovascular examinations: non-invasive and invasive. The former includes CT angiography and MR angiography, which have an effective detection rate of 90% for intracranial aneurysms up to 2 mm in size and 100% for those up to 5 mm in size. The latter is cerebral angiography, also known as Digital Subtraction Angiography (DSA), which is the gold standard for the detection of aneurysms and other vascular diseases, and the detection rate of intracranial aneurysms is close to 100%.