Venography is as study that injects dye into a vein using a catheter that visualizes venous blood flow. As the dye flows through your veins, X-rays are taken. This lets the physician take a look at the condition of your veins, especially in your legs. A venogram can be used to help diagnosed conditions like Deep Vein Thrombosis (DVT). This test takes several minutes, and you can go home the same day of the procedure.