Cerebral angiography is a brand-new X-ray examination technique that has been widely used in clinical practice since the 1990s. The basic principle is to select an entry artery (usually the right femoral artery), place an arterial sheath through the arterial sheath, select different catheters through the arterial sheath tube, guided by the guidewire, enter the artery to be displayed, then inject iodine-containing contrast agent, and then continuously take pictures along the vascular track passed by the contrast agent through the electronic computer-assisted imaging of cerebral blood vessels for digital subtraction angiography (DSA). DSA can not only clearly display the blood vessel images of internal carotid artery, vertebral-basilar artery, intracranial blood vessels and cerebral hemispheres, but also measure the blood flow of the arteries, so DSA is of great significance in the examination and diagnosis of head and neck vascular and spinal cord vascular diseases. The following are the main indications for cerebral angiography: (1) Ischemic cerebrovascular disease. This includes cerebrovascular stenosis, transient ischemic attack (TIA), and cerebral infarction found by other diagnostic imaging techniques. Intracranial artery stenosis is an important cause of stroke onset or recurrence, and about 30-70% of cerebral infarction is related to intracranial and extracranial artery stenosis; cervical vascular ultrasound can be used as a preliminary judgment, but DSA must be performed for definitive diagnosis. (2) Hemorrhagic cerebrovascular disease. Young patients with cerebral hemorrhage should be highly suspected of intracranial arteriovenous malformation; middle-aged and old patients with subarachnoid hemorrhage, 90% of the cause of intracranial aneurysm; suspected arteriovenous fistula, etc. should be cerebral angiography for clear diagnosis. (3) The patient has obvious dizziness, especially when vertebrobasilar artery pathology is suspected. Obvious asymmetry of blood pressure in the upper limbs (>20 mmHg) or blood stealing from the subclavian artery. (4) Clinical suspicion of venous sinus inflammatory or non-inflammatory thrombosis. (5) Non-atherosclerotic vascular disease (including neurocutaneous syndromes, hereditary diseases, vasculitis, etc.), and smoky disease. (6) Head and neck trauma, traumatic intracranial hemorrhage, rhinorrhea, craniofacial vascular lesions. (7) Intracranial tumor occupancy. (8) Central retinal arterial and venous thrombosis. In addition to being used for examination and diagnosis, DSA has unique therapeutic significance in the interventional treatment of neurological vascular diseases (including ultra-early thrombolytic therapy for cerebral infarction, stenting of intracranial vascular stenosis, embolization of cerebral aneurysms, embolization of cerebral arteriovenous malformations, and treatment of spinal vascular diseases, etc.). Neurological interventions are less risky than surgical procedures (e.g. cervical vascular plaque debridement, cranial aneurysm clamping, etc.) and are minimally invasive. Clinical practice has shown that dangers and complications of cerebral angiography are relatively rare. Contraindications include: (1) iodine allergy; (2) serious bleeding tendency; (3) serious liver, kidney, heart, lung disease patients; (4) puncture skin or soft tissue infection. Anesthesia method is, adults use local anesthesia, pediatric or uncooperative people can use local anesthesia plus basic anesthesia.