Angiography is a medical imaging technique used to visualize the blood vessels in the body. It involves injecting a contrast dye into the bloodstream and taking X-ray images to track the flow of blood through the vessels. Angiography is commonly used to diagnose and treat conditions such as blockages, aneurysms, and malformations in the blood vessels. It can also be used to guide minimally invasive procedures such as angioplasty and stent placement. Angiography plays a critical role in the diagnosis and treatment of cardiovascular and vascular diseases.