What is a venogram?
A venogram is an x-ray test that involves injecting x-ray contrast material (dye) into a vein to shows how blood flows through your veins. This allows a physician to determine the condition of your veins. A venogram is commonly used to:
• find blood clots in the veins
• assess varicose veins before surgery
• find a vein in good condition to use for a bypass procedure
• help a physician place an IV or a medical device, such as a stent, in a vein
• guide treatment of diseased veins.
What to expect
X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special detector. Different parts of the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays to pass through them. As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air appears black.
Veins cannot be seen on an x-ray, so a special dye (called contrast material) is injected into veins to make them visible on the x-ray.
Other than medications, you may be instructed to not eat or drink anything for several hours before your procedure. You may be allowed to drink clear liquids on the day of your procedure. You should inform your physician of any medications you are taking and if you have any allergies, especially to barium or iodinated contrast materials. Also inform your doctor about recent illnesses or other medical conditions.