What is a Venogram?

A venogram is an imaging test that can pinpoint the location, size, and shape of an obstruction or blood clot in your veins. The test uses a contrast dye, which is injected into your veins, to help a doctor clearly see blood flow through the veins using an X-ray or computed tomography (CT) scan.

Why is a Venogram Necessary?

A doctor will recommend a venogram to investigate a possible blood clot or obstruction in the veins. This could help identify diseases such as deep vein thrombosis, pulmonary embolism, or venous insufficiency. It can also help diagnose a vein inflammation condition, such as phlebitis, or an arteriovenous malformation, which is an abnormal connection between arteries and veins.

When is a Venogram Used?

Venograms are most often used to investigate suspected venous diseases, although they are sometimes also used to guide procedures, such as placing a catheter in the vein or to assist in a bypass operation. The dye used in a venogram can help a healthcare provider make informed decisions about the treatment of certain diseases.

Venogram Preparation

Prior to your venogram, your doctor will review your medical history and ask about any medications you are taking. He or she may also recommend that you stop taking certain medications before the test or that you discontinue anticoagulant medications for a period of time. It is important to let your doctor know if there is a possibility that you are pregnant.

You may need to fast before the test. This will depend on the type of contrast dye that your doctor is using. Your doctor will instruct you about any preparation instructions prior to your venogram.

Venogram Procedure

During the venogram, you will be asked to lie flat on your back. A contrast dye will be injected into the vein and images will then be taken. The dye can be uncomfortable but should not cause any pain. Depending on the area being assessed, the test may take up to an hour.

Types of Venograms

There are several different types of venograms:

  • Lower extremity venogram – assesses veins in the legs
  • Venous doppler – assesses flow within veins
  • Pelvic venogram – assesses veins in the pelvis
  • Upper extremity venogram – assesses veins in the arms or hands

Risks of a Venogram

The risks of a venogram are typically very low. The contrast dye can sometimes cause an allergic reaction, but this is unusual. Your doctor may advise you to take a medication prior to the test if you have a known allergy to contrast dyes. Other rare complications include an infection at the injection site and a blood clot in the vein.

Venogram Results

Your doctor will review the results of your venogram and provide you with a diagnosis and treatment plan. The venogram images can also be used to measure the amount of blood in the veins, the size, and location of a clot, and the degree of narrowing in the vein.