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.

This test is used to identify and locate blood clots in the veins of the legs.

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The catheter is then withdrawn, and the puncture site is bandaged.

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.

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.