There are three common methods of cerebral angiography used to diagnose cerebrovascular disease. The first is cerebral angiography (MRA) performed by an MRI machine, the second is cerebral angiography (CTA) performed by a CT machine, and the third is cerebral angiography (DSA) that requires a femoral artery cannula at the root of the thigh and is done under a digital subtraction angiography machine. MRA is non-invasive, can be done without even contrast injection, and can be performed at the same time as an MRI, but has the worst resolution and can be used as a screening method. CTA is also a non-invasive method that requires injection of contrast agent containing iodine and requires knowledge of kidney function before doing so (contrast agent is excreted through the kidneys). It can be done quickly, with less patient pain and improved resolution compared to MRA, and can be used as a method for rapid diagnosis of cerebral aneurysms. DSA is the most accurate method of cerebral angiography with the highest resolution and is the “gold standard” for diagnosing cerebrovascular disease. The disadvantage is that it requires arterial cannulation and is somewhat invasive. In clinical practice, if a case of cerebrovascular disease is considered by MRA or CTA, especially when further treatment is needed, DSA is often needed to make a final diagnosis. For example, in patients with subarachnoid hemorrhage, CTA can be performed in an emergency, and if a cerebral aneurysm is found, DSA can be performed and interventional embolization treatment can be performed at the same time. DSA examination is also necessary for periodic review after craniotomy or interventional embolization for cerebral aneurysm. If the patient really does not want to have DSA examination, personal experience is that for patients after craniotomy, CTA examination can be performed; for patients after interventional embolization, MRA examination can be performed.