A venogram is a procedure that uses X-rays to record images of the blood flowing through the veins of the body. It determines the condition of veins and looks for the source of blood clots in patients with suspected embolism. Veins are clearly visible on the X-ray images when a special contrast dye is injected into them. Veins from various parts of your body such as legs, pelvis, arms, heart or kidney can be observed in the venogram. Computed tomography (CT) venography makes use of X-rays emitted by a CT scanner to view images of veins in various parts of the body. This can be done with or without contrast.