Digital Subtraction Angiography (DSA) is a medical imaging technique used to visualize blood vessels in the body. It involves taking two X-ray images: one before a contrast dye is injected and another after. The computer then subtracts the first image from the second, highlighting the blood vessels and making them easier to see. This method is particularly useful for diagnosing conditions like arterial blockages or aneurysms. By providing clear images of the blood vessels, DSA helps doctors plan treatments and monitor the effectiveness of procedures, ensuring better patient outcomes and safer interventions.