A venogram is an X-ray test that takes pictures of blood flow through the veins in a certain area of the body.

During a venogram, a special dye (contrast material) is put into your veins so they can be seen clearly on an X-ray picture. A venogram looks at the condition of your veins and the valves in your veins.

A venogram can show the veins in your legs, pelvis, or arm; the veins leading to the heart; or the veins leaving your kidneys. Venography also may be done to find a blood clot (deep vein thrombosis, or DVT). Blood clots in the deep veins can be serious because the clot or part of it can break off and move through the blood vessels. A clot that blocks an artery in your lung (pulmonary embolus) can be life-threatening.

See pictures of normal blood flow and blood flow blocked by a blood clot (thrombus).

Why It Is Done

Venography is done to:

• Find blood clots in the deep veins of your leg, arm, or pelvis (deep vein thrombosis, or DVT).
• Find healthy veins to be used in coronary artery bypass graft (CABG) surgery.
• Find the right placement in blood vessels for medical devices such as filters or stents.
• Put a thin flexible tube (catheter) in your kidney (renal) vein to collect a blood sample.
• Check the condition of the valves in the veins of your leg when surgery for varicose veins is being considered.
• Guide the placement of a special intravenous (IV) line that is used for long-term medicine or fluid treatment.

How To Prepare

Do not eat for 4 hours before a venogram. You may drink only clear fluids for 4 hours before the test.

Before a venogram, tell your doctor if you:

• Are or might be pregnant.
• Are allergic to any medicines, contrast material, or iodine dye.
• Have bleeding problems or take blood-thinning medicines, such as aspirin, heparin, or warfarin (Coumadin).
• Have asthma.
• Have had a severe allergic reaction (anaphylaxis).
• Have had kidney problems.
• Have diabetes, especially if you take metformin (Glucophage).

You will be asked to sign a consent form for this test. Talk to your doctor about any concerns you have regarding the need for the test, its risks, how it will be done, or what the results may mean. To help you understand the importance of this test, fill out the medical test information form(What is a PDF document?).

How It Is Done

A venogram usually is done in a hospital X-ray department by a radiologist and an X-ray technologist. A nurse may also be present.

Take off all jewelry and metal objects before the test. You will need to take off all or most of your clothes. You will be given a gown to use during the test. You may be asked to urinate just before the test begins.

Arm, pelvis, or leg venogram