What Is a Venogram?
A venogram is a test that lets your doctor see your veins on an X-ray. Veins typically cannot be seen on a normal X-ray. This test involves the injection of a liquid called contrast dye. The dye is an iodine-based solution that allows your veins to be seen on X-ray.
Venography allows your doctor to assess the size and condition of your veins. It can also be used to diagnose medical conditions like blood clots and tumors. The test can also show your doctor any vein abnormalities that may be causing pain or swelling in your limbs.
Types of Venography
A venography is usually used to visualize the veins in the legs or stomach, but it can be used on any area of the body. Your doctor will choose which type of venography is appropriate for you depending on the reason for your test. The types of venography include the following:
- Ascending venography allows your doctor to see the location of deep vein thrombosis, or blood clots, in your legs.
- Descending venography allows your doctor to measure the function of the valves in the deep veins.
- Upper extremity venography allows your doctor to look for blockages, blood clots, or vascular abnormalities in the veins in your neck and arms.
- Venacavography allows your doctor to assess the function of your inferior vena cava, which brings blood to your heart
Each type of venography uses the same contrast dye and X-ray machine.
Preparing for a Venography
You and your doctor should discuss all of your medications and allergies before undergoing a venography. People who are allergic to shellfish or iodine may be especially sensitive to the contrast dye.
Let your doctor know if you’re pregnant. Radiation exposure from X-ray is minimal but carries a slight risk to a developing fetus.
You might be advised to fast for four hours before the venography. Make sure to remove all jewelry before the venography.
You’ll be given a hospital gown to wear during the venography to make the testing areas easy to access. A healthcare provider will clean one of your feet with a sterile fluid and insert an intravenous line. Then, they’ll inject the vein with the contrast dye.
You might feel warm, develop a slight headache, or feel nauseated as the contrast dye travels through your body. Let them know if you have trouble breathing or feel itchy after the injection of the dye. This could indicate an allergic reaction.
People who have multiple food or drug allergies are more likely to display an allergic reaction to contrast dye. Those who have hay fever or asthma also have an increased risk of allergy. People who have kidney disease are also at risk.
You most likely won’t be tested for allergies to contrast dye before you have a venography. This is why it’s important to let your doctor know if you have previously reacted to the dye. The doctor might give you an antihistamine before using contrast dye to prevent itching or they may decide not to risk a reaction and will not use the dye.
X-rays will be taken at regular intervals as the contrast dye moves throughout your legs and lower body. The exam generally takes between 30 to 90 minutes. After the X-rays are finished, they’ll bandage the injection site.
You’ll rest for a short period after the venography, and your vital signs will be monitored. You can usually go home the same day as your venography. Make sure to drink lots of water following your procedure to stay hydrated and clear out the contrast dye from your body.
The following symptoms may indicate an infection or allergies to the contrast dye:
- redness at the injection site
- swelling at the injection site
- a fever
If you have any of these symptoms, your condition may need to be monitored for a longer period in the hospital.
Results of Venography
Your doctor will get a report of the results from a radiologist. A radiologist is a doctor who is trained to read the radiology results. Your doctor will discuss any abnormal findings, such as blood clots, blockages, or dysfunctional valves, with you. Your doctor can treat these abnormalities or monitor them at follow-up appointments.
Risks of Venography
People who have kidney disease, diabetes, or take the drug metformin (Glucophage) to control glucose levels may be at a higher risk for going into kidney failure after a venography. Studies reported in the American Academy of Family Physicians have noted that between 0.1 percent and 13 percent of people who have contrast dye during medical procedures can experience kidney failure.
Other factors may make venography more difficult to perform, especially if you’re obese, you cannot lie still during the X-ray process, or you have severe swelling in your legs.
Obesity and excessive swelling in your limbs make the veins harder to locate and see during a venography. You must also be able to remain still for the length of the test so the X-ray technician can get accurate images.
Discuss your overall health with your doctor to determine if the benefits of venography outweigh the risks.