Lower extremity venography is a test used to see the veins in the leg.
X-rays are a form of electromagnetic radiation like light, but of higher energy, so they can go through the body to form an image on film. Structures that are dense (such as bone) will appear white, air will be black, and other structures will be shades of gray.
Veins are not normally seen in an x-ray, so a special dye (called contrast) is used to highlight them.
Phlebogram - leg; Venography - leg
How the test is performed:
This test is done in a hospital. You will be asked to lie on an x-ray table. Local anesthetic is used, and you may ask for a sedative if you are anxious about the test.
The healthcare provider places a needle into a vein in the foot of the leg being looked at, so that an intravenous (IV) line can be inserted. The contrast dye flows through this line into the vein. A tourniquet may be placed on your leg so the dye flows into the deeper veins.
X-rays are taken as the dye flows through the leg.
The catheter is then withdrawn, and the puncture site is bandaged.
How to prepare for the test:
You will wear hospital clothing during this procedure. You will be asked to sign a consent form for the procedure. Remove all jewelry from the area being imaged.
Tell the health care provider if you are pregnant, if you have allergies to any medication, which medications you are taking (including any herbal preparations), and if you have ever had any allergic reactions to x-ray contrast material or iodine substance.
How the test will feel:
The x-ray table is hard and cold, so you may want to ask for a blanket or pillow. You will feel a sharp poke when the intravenous catheter is inserted. As the dye is injected, you may experience a burning sensation.
There may be tenderness and bruising at the site of the injection after the test.
Why the test is performed:
This test is used to identify and locate blood clots in the veins of the legs.
Free flow of the blood through the vein is normal.
What abnormal results mean:
Abnormal results may be due to a blockage caused by blood clots, tumors, or inflammation.
What the risks are:
- Allergic reaction to the contrast dye
- Kidney failure, especially in the elderly or persons with diabetes who take the medicines Glucophage or metformin
- Worsening of a clot in the leg vein
There is low radiation exposure; however, most experts feel that the risk of most x-rays is smaller than other risks we take every day. Pregnant women and children are more sensitive to the risks of the x-ray.
Ultrasound is used more often than this test because it has fewer risks and side effects. MRI and CT scans may also be used to look at the veins in the leg.
Ginsberg J. Peripheral venous disease. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 81.