Angiography is a medical imaging technique used to visualize blood vessels in various parts of the body, particularly those supplying the heart (coronary angiography) or the brain (cerebral angiography). It involves injecting a contrast dye into the bloodstream and then taking X-ray images to capture the flow of blood through the vessels. This procedure helps doctors identify blockages, narrowings, or abnormalities in the blood vessels, which can be indicative of conditions such as coronary artery disease, stroke, or aneurysms. Angiography plays a crucial role in diagnosing and planning treatment for cardiovascular and neurovascular conditions, allowing healthcare professionals to make informed decisions and provide appropriate care to patients.